Johns Hopkins Health Alerts - Vision

Eye on the Eyedrops

Tue, 02 Mar 2010 06:00:00 CST

If you have glaucoma, you probably use eyedrops at least once a day to lower the pressure within your eye. Although using eyedrops may sound simple enough, in reality, it's not always easy to get them in your eye or to remember to take them. This guide offers tips on the best ways to get your eyedrops exactly where they're supposed to be.

The first barrier for many people is remembering to use their eyedrops. If you find that you're forgetting your eyedrops, try using these strategies.

Develop a routine. Associate using eyedrops with another activity that you do each day, such as brushing your teeth.

Use reminders. Stick a note on your bathroom mirror or refrigerator or ask your spouse or other family members to remind you to use your eyedrops.

Simplify your regimen. Ask your doctor to simplify your eyedrop regimen; for example, you may be able to switch to once-a-day drops or a combination product that contains two types of eyedrops in one bottle.

Following these simple tips can help you get your eyedrops into your eye.

Lie down. The more horizontal your face, the better the chances that the eyedrop will go in your eye and stay there. Even if you only hit the eyelids, by staying horizontal and blinking after the drops hit the corner of your eyelids, enough will get in your eye.

Position the bottle and your eyelid. Hold the bottle vertically between your thumb and index finger and about an inch above your eye. With your other hand, carefully pull down your lower eyelid with your index finger, creating a small pocket, which increases the amount of eye surface available to catch the eyedrop.

Carefully close your eye. After the eyedrop gets in your eye, close it, but don't squeeze or close it too tightly. Gently press the inside corner of your eyelid at your tear duct, for at least one minute. This will allow your eye to absorb the medicine.

Wait before using other drops. If you use several kinds of eyedrops or more than one drop of a single medication, wait at least one minute before applying the next drop.

Troubleshooting: Shaky hands? If your hands are too shaky, try resting your palm on your cheek as you apply the eyedrops. Eyedrops still not going in? Lie down, turn your head to the side and gently close your eyes. Place a drop on the inside corner of your eyelid, then open your eyes slowly. The drop should go in. If it's unclear whether a drop went in, try another. Your eye can only hold about one eyedrop, so any excess will roll away.

Do Antioxidants Prevent Cataracts and Age-Related Macular Degeneration?

Fri, 19 Feb 2010 06:00:00 CST

It's not just what you take out of your diet that might help your eye health, it's also what you add. New research suggests that foods rich in the antioxidants lutein and zeaxanthin (pronounced loo-tein and zee-uhzan- thin), and vitamins E and C may lower your risk of developing cataracts. Lutein- and zeaxanthin- containing foods also appear to help protect against advanced age-related macular degeneration. Here’s what the research shows.

Researchers speculate that free radicals -- molecules that damage healthy cells -- may lead to the formation of cataracts and worsening age-related macular degeneration. Antioxidants help prevent the damage free radicals cause.

Lutein and zeaxanthin. These carotenoids, the kind of antioxidants that color yellow and leafy dark green vegetables, such as kale, spinach, and carrots, are also found in the lens and retina of the eye. Data from the 10-year Women's Health Study, which began in 1993 and involves more than 35,000 women, found that those who ate almost 7 mg of lutein and zeaxanthin -- approximately the amount in one half cup of cooked spinach -- per day were 18% less likely to develop cataracts that those who ate only about 1 mg per day.

Researchers believe that this pair of antioxidants may help build and maintain the pigment layer of the retina. Another theory is that they help filter out blue light, protecting the eye from sunlight damage.

Vitamins E and C. The same investigators who reported the cataract-carotenoid findings also looked at the effect of vitamins E and C. They found that women who consumed the most vitamin E from food and supplements, about 262 mg a day -- approximately the equivalent of 3 cups of almonds -- were 14% less likely to develop cataracts than those who consumed only 4 mg a day. Several other studies have found similar results.

This study found little association between vitamin C and lowered risk of cataracts. But several other epidemiological studies, including the Nurses' Health Study and the Beaver Dam Eye Study, have found a lower risk of cataracts or cataract progression in those who took high levels of vitamin C.

Practical Advice to Help You See Better When You Drive

Fri, 06 Nov 2009 06:00:00 CST

Do you sometimes have trouble seeing clearly when you drive? The American Academy of Opthalmology recommends that everyone between ages 40 and 65 have an eye exam every two to four years. If you're over age 65, you should see your eye doctor every one to two years, particularly to check for conditions such as cataracts, glaucoma, and age-related macular degeneration. Between check ups, if your vision changes or you have trouble driving at night, let your eye doctor know right away. What else can you do? In this Health Alert, Johns Hopkins provides practical advice to help you see better when you drive …

Upgrade Your Eyewear -- You may also want to investigate antireflective lenses for your eyeglasses. These lenses minimize glare and allow more light to enter the eye than regular plastic lenses, which let only 91% of available light enter. Antireflective lenses are especially helpful at night, cutting the reflections on your lenses from streetlamps and headlights.

Polarized sunglasses also may be helpful especially for reducing glare. Polarized lenses have a laminated surface that contains vertical stripes, which allows the light to enter a lens vertically, blocking the horizontal bright light.

Prepare Your Car and Know Your Limits -- There are a number of steps you can take for a safer driving experience.

Keep your headlights, taillights, mirrors, and windshields clean. These may sound like housekeeping details, but they can improve your road vision. Give your eyeglasses a shine before you set out as well.

Keep a spare pair of eyeglasses and sunglasses in your glove compartment so that you never find yourself driving without a pair handy.

If you're buying a car, skip the darkened or tinted windows. Also, pick a model with easy-to-read symbols, large dials, and an instrument panel that brightens well at night. In addition, ask for a rearview mirror that automatically filters out glare.

When you have your car serviced, make sure the lights are at full power and properly aligned so they don't affect the vision of drivers coming toward you.

Plan long road trips with your eyes in mind, stopping every few hours to rest your body and your eyes.

Avoid traveling at night, dawn, and dusk, especially in places you don't know well. And skip the crowded highways for quieter routes.

If you know you're uncomfortable driving, consider taking a refresher class. Refresher classes are offered by the AARP, The Automobile Association of America (AAA), and the National Safety Council. Another option is to work on improving your driving skills with a driving instructor or vision rehabilitation specialist.

If you take prescription medicines, such as antihistamines or blood pressure medication, check with your doctor about whether they may affect your vision.

7 Tips to Help You Stay Safe With Low Vision

Fri, 29 Jan 2010 06:00:00 CST

Dealing with vision loss is challenging. For people with glaucoma, macular degeneration, or another vision problem, low-vision aids can help optimize remaining vision and improve the ability to perform daily activities.

Some examples of low-vision aids are telescopes, closed-circuit televisions (a small television camera is mounted on a movable tray; documents or other objects are moved under the camera and viewed on a small monitor), magnifying glasses, clocks and phones with large numbers, and large-print reading materials. Telescopes and closed-circuit televisions require an evaluation and prescription from an eye care professional as well as training in how to use them.

Ophthalmologists and low-vision counselors recommend these simple, practical strategies to help patients with low vision maintain their independence.

Always leave doors completely open or completely closed. This reduces the risk of accidentally walking into the door edge if you have low vision.

Tack down loose rugs and use non-slip mats beneath them. Or you can hold down rugs with furniture to prevent slipping and tripping.

Tape a colorful piece of paper to all clear glass doors. If you have low vision, this will help you determine whether the door is open or closed and prevent collisions.

Avoid using glass-topped coffee or end tables. The edges are extremely difficult to see, making bumping injuries more likely if you have low vision.

Mark the important settings on the dials of the stove, washer, dryer, and other appliances using brightly colored tape.

Mark the outer edge of all indoor and outdoor stairs. Use a strip of paint or non-skid material in a color that contrasts with the rest of the step. The strip should extend about two inches from the edge -- both horizontally and vertically -- and should go across the full width of the step. This reduces the chances of tripping or falling on the stairs if you have low vision.

Have someone help you arrange clothing if you have color-vision problems. Separate items according to color and then use labeled dividers to identify them.

What Causes Dry Eye?

Fri, 08 Jan 2010 06:00:00 CST

Do you have dry eye? Dry eye syndrome is a condition in which your eye produces too few tears or poor quality tears. Although it rarely causes blindness, it can affect the quality or sharpness of your vision. Left untreated, dry eye syndrome can make it difficult to read or drive, for instance, producing a significant adverse effect on your quality of life. What causes dry eye? Here’s an explanation, in brief.

Age is often the culprit behind dry eye. As we age, our bodies -- especially those of females -- produce less oil. At age 65, for instance, we make 60% less oil than we did at age 18. Without oil to seal the watery layer of the eye, the tear film evaporates more quickly, leaving dry spots on the cornea.

Aging also decreases the amount of tears we produce. And in women, menopause and its hormonal shifts also bring less tear production. Moreover, aging can be associated with several alterations in the eyelid position, which produce structural problems that may cause the lower eyelid to turn out (ectropion) or turn in (entropion).

In both cases, the eyelids do not close properly, leaving them exposed to the air, which may exert a drying effect. Tear ducts, too, can have structural problems that can cause dry eye, although these are not associated with aging.

Other causes of dry eye syndrome include:

Medications. Some medicines interfere with the secretions of eye glands, leading to or exacerbating dry eye.

Environmental factors. Sunny, dry, or windy weather; high altitudes; heaters; smoke and other air pollutants; hair dryers; air travel; and air conditioners can all dry out the tear film covering your eye. Logging in a lot of TV, computer, driving, and reading time can dry out this film as well, because during these activities, you blink less, priming you for dry eye.

Contact lenses. As the lenses lose moisture when you wear them, they absorb tear film, leading to dryness.

Diseases. Dry eye is associated with thyroid disease, rheumatoid arthritis, and systemic lupus. Some people who have skin conditions, such as psoriasis, eczema, and rosacea, also may be at risk. Dry eye is also prevalent among people who have Sjögren's syndrome, a condition that dries the mouth and mucous membranes.

Blepharitis. An inflammation of the edges of the eyelids, this condition occurs when eye glands don't produce enough oil, a common cause of dry eye.

Refractive eye surgery. Eye surgeries, such as laser-assisted in situ keratomileusis (LASIK), that correct near- and farsightedness and astigmatism can sever the nerves that stimulate tear production. But the resulting dry eye generally improves as the eye heals.

Protect Your Eyes With Omega-3s

Fri, 18 Dec 2009 06:00:00 CST

Is there anything you can do to protect your eyes against age-related macular degeneration? The importance of omega-3 fatty acids, found in fatty fish and other foods, in heart disease prevention is well documented. Now research suggests that eating oily fish can help slow or prevent age-related macular degeneration. Read what the experts have found.

The causes of age-related macular degeneration -- both non-neovascular (also known as nonexudative, atrophic, or dry) and neovascular (also called exudative or wet) -- are unknown, although there are known risk factors for both forms of the disease.

Increasing age, farsightedness, cigarette smoking (and possibly exposure to secondhand smoke), a light-colored iris, obesity, and a family history of age-related macular degeneration all raise the risk of both types. In addition, high blood pressure appears to be linked to a greater risk of neovascular age-related macular degeneration, as are high levels of C-reactive protein a marker of inflammation in the body.

Studies published in the Archives of Ophthalmology (Volume 124, pages 981) point to fish oil as a potent anti-inflammatory, protecting high-risk individuals against age-related macular degeneration.

Eating oily fish like salmon, herring, tuna, and mackerel one to three times a week appears to cut the risk of age-related macular degeneration, according to two studies. In a study at the University of Sydney Eye Clinic in Australia, researchers followed nearly 3,000 men and women for five years. Those who ate fish once a week had a 40% reduced risk of early age-related macular degeneration compared with those who ate fish only once a month; those who ate fish three times a week had a reduced risk of late age-related macular degeneration.

In another study of almost 700 male twins by researchers at the Massachusetts Eye and Ear Infirmary and Harvard Medical School, those who ate fish at least twice a week lowered their risk of age-related macular degeneration by 45% compared with people who ate fish less than once a week.

Researchers believe the protection stems from the omega-3 fatty acids that are plentiful in oily fish. Other studies have shown that omega-3s reduce inflammation that results from free radicals, molecules that damage healthy cells, including those in the retina.

Should You Take Avandia for Diabetic Retinopathy?

Fri, 25 Sep 2009 06:00:00 CDT

If you have diabetic retinopathy, what can you do to slow its progression? Of course, tight blood glucose control lessens the risk that retinopathy will get worse. And treating other conditions, such as high blood pressure and abnormal cholesterol levels, may also slow progression. What about Avandia? A reader asks: I’ve heard that the diabetes medication Avandia can slow the progression of diabetic retinopathy. Should everyone with this condition be taking it?

Johns Hopkins answers: Not necessarily. Rosiglitazone (Avandia) is currently prescribed to control high blood sugar in people with type 2 diabetes. Recently, a study in the Archives of Ophthalmology reported that it may also inhibit the growth of new blood vessels in the eye, delaying the onset of a more advanced stage of diabetic retinopathy known as proliferative diabetic retinopathy (PDR).

Researchers reviewed the medical records of 282 people with diabetes. This included 124 people treated with Avandia and 158 who were not. A total of 38 people were at significant risk of progression to PDR. Both groups were followed for an average of three years. Among the high-risk group, those who took Avandia had a 60% lower risk of PDR than those who didn’t take it. Also, fewer people in the Avandia group had a loss of three or more lines on a standard vision chart.

The news isn’t all good, however. The FDA now requires Avandia to carry a label warning that it has been shown to increase the risks of heart attack and heart failure.

The bottom line: It’s premature to recommend taking Avandia to prevent the progression of diabetic retinopathy. There are many other effective oral medications for type 2 diabetes. For now, if your condition is under control while using another medication, there’s no reason to switch -- even if you have diabetic retinopathy.

Advance in Glaucoma Diagnosis

Fri, 16 Oct 2009 06:00:00 CDT

An eye examination for glaucoma involves measuring IOP (intraocular pressure – the pressure exerted by the fluids inside the eyeball), viewing the optic nerve, and testing the visual fields. Now a new test may aid in the detection and treatment of glaucoma.

Using new technology called Fourier-domain optical coherence tomography (FDOCT), researchers have obtained high-resolution images of the front of the eyeball, allowing them to clearly see the angle between the iris and the cornea without touching the eye.

Currently, doctors perform a test called gonioscopy using a special contact lens that is pressed into the eye to see if the angle is open, thereby allowing aqueous fluid to drain, or is narrow and at risk for closing because of fluid back up. FDOCT also allows them to see the trabecular meshwork and Schlemm's canal -- parts of the eye that play a crucial role in the development of glaucoma.

The researchers were able to scan the eyes of six healthy patients and six with glaucoma at an imaging depth of 6.3 mm, a significant improvement over the 3- to 4-mm depth of traditional OCT. And the high-speed, high-resolution capabilities resulted in clear, unobstructed images.

If FDOCT moves from the lab to doctors’ offices, ophthalmologists will be better able to assess changes in the eye's structures, improving the accuracy of glaucoma diagnosis and treatment. And they will be able to observe changes in glaucoma progression. Glaucoma surgeries, dependent on finding the exact location of Schlemm's canal, also may become more accurate, easier, and more efficient.

Reported in Archives of Ophthalmology (Volume 126, page 765)

Fight Cataracts With Antioxidants

Fri, 04 Sep 2009 06:00:00 CDT

Cataracts can occur at any age, but they are most common later in life. In the United States, 75% of people over age 60 have some sign of cataracts. It is estimated that more than 20 million Americans over age 40 have had a cataract. That number is anticipated to reach about 30 million by the year 2020. Is there anything you can do to avoid cataracts?

Recent research reported in the Archives of Ophthalmology (Volume 126, page 102) reveals that women who eat lots of yellow or dark leafy vegetables -- which contain high amounts of lutein and zeaxanthin compounds -- and consume more vitamin E from foods and supplements may have a lower risk of developing cataracts than those who consume lower amounts of these antioxidants.

Researchers analyzed dietary information from almost 36,000 women in the Women's Health Study. During the study, 2,031 developed cataracts. Those with the highest intake of lutein-zeaxanthin were 18% less likely to develop cataracts than those with the lowest intake.

Vitamin E lowered cataract risk by 14% in those who had the highest intake. However, results from other studies of vitamin E have been mixed, and findings from five randomized, controlled trials yielded little evidence that the vitamin is protective. Vitamin C did not appear to lower risk in this study, but results from other investigations also have been mixed.

Bottom line: Evidence that nutrient intake can help prevent cataracts is weak and inconsistent. And more studies are needed before scientists can recommend supplement use. However, enjoying foods that contain lutein and zeaxanthin (spinach and other leafy greens as well as egg yolks) and vitamin E (leafy greens, nuts, and vegetable oils) won't hurt your eyes and is a boon to your overall health.

Cataract Basics

Fri, 24 Jul 2009 06:00:00 CDT

While there’s currently no effective drug therapy to prevent cataracts from forming, cigarette smoking, certain drugs, eye injuries, sunlight, diabetes, and even obesity can increase your risk.

If you’re in your forties or fifties, you probably know someone who has cataracts. That’s because while cataracts can occur at any age, they are most common later in life. About 75% of people in the United States over age 60 have some sign of cataracts. And it is predicted that by 2020 approximately 30.1 million Americans will have cataracts. Cataract surgery is the most commonly performed surgical procedure in the United States. More than 1.5 million cataract operations are performed each year.

What is a cataract? A cataract is an opacification (cloudiness) of the eye’s normally clear crystalline lens. Derived from the Latin word meaning “waterfall,” the term cataract arose from the ancient misconception that cataract symptoms were caused by evil liquids that mysteriously flowed into the eye.

The cause of most cataracts is unknown, but at least two factors associated with aging contribute to cataract development:

First, clumping of proteins in the lens leads to scattering of light and a decrease in the transparency of the lens.

Second, the breakdown of lens proteins leads to the accumulation of a yellow-brown pigment that clouds the lens.

Researchers have found certain chemical changes in the eyes of people with cataracts. These changes include a reduced uptake of oxygen by the lens and a rise in the water content of the lens, which is later followed by dehydration. When cataracts form, levels of calcium and sodium in the lens increase, and levels of potassium, vitamin C, and protein decrease. In addition, lenses with cataracts appear to be deficient in the antioxidant glutathione. However, studies on the use of medications or vitamins to alter the levels of these substances in the lens have not produced promising results. Currently, there is no effective drug therapy to prevent cataracts from forming. But cigarette smoking, certain drugs, eye injuries, sunlight, diabetes, and even obesity can increase the risk of cataracts.

What are the symptoms of cataracts? Cataracts form painlessly. The most common symptom is cloudy or blurry vision. Everything becomes dimmer, as if seen through glasses that need cleaning. Most often, both eyes are affected, though vision is usually worse in one eye than in the other. Other symptoms include glare, halos, poor night vision, a perception that colors are faded or that objects are yellowish, and the need for brighter light when reading.

In some cases, double vision occurs. This is caused by the passage of light through a lens that has irregular areas of opacity, which can split the rays of light from a single object and focus them on different parts of the retina. Another symptom of cataracts is the need for frequent changes in eyeglass and contact lens prescriptions. These symptoms can develop in a matter of months or almost imperceptibly, over many years.

Living Better With Poor Vision

Fri, 03 Jul 2009 06:00:00 CDT

Taking a brisk walk is tough to do when you can’t see well. Still, some people with limited vision clip along quite well, and researchers at Johns Hopkins are trying to understand why some with poor vision fare better than others and which of their lessons can be passed along.

The Johns Hopkins studies are part of the Salisbury Eye Evaluation Project (SEE) begun in 1993, when scientists at Johns Hopkins began gathering the vision and health data of roughly 3,000 elderly residents of Salisbury, MD. In the past, research has focused on common problems such as reading, face recognition, and sharpness of vision, measurements that can be taken from seated subjects.

But within the last five to 10 years, technology has improved the ability to measure vision in motion (through virtual environments, portable eye trackers, and faster computers), enabling SEE researchers to concentrate on a relatively new area: the effect that limited peripheral vision has on movement.

What the studies make clear is that vision alone does not determine how well one navigates a trail. In the studies those who were able to walk most quickly and efficiently used both external and internal cues to guide their walks. In other words, they were better able to create a mental map of the environment to augment their sense of where they were.

Lessons to share -- People can learn to compensate for poor peripheral vision by using nonvisual cues such as sounds, muscle responses, and body systems that let them know where they are in space. Those with compromised vision can learn to draw on internal maps of where they are, lessening dependence on visual cues. For instance, when you enter a room through one door, observing a chair on the right and a lamp on the left, and then enter the next time by another door, you can rotate the room in your mind, reorienting yourself to the new entrance.

Visual aids are available as well. In addition to the traditional white cane, there are now sonar devices that provide audible cues about what’s in the immediate environment. Image enhancers like the Low Vision Enhancement System developed by Johns Hopkins and NASA can enlarge images of surroundings. And at key locations like public restrooms in a number of cities in the United States and other countries, Talking Signs are now in use, transmitting voice messages about their location to small handheld boxes.

Perhaps the best news from the SEE studies is that with training and aids, poor vision doesn’t have to mean the end of travel, exercise, or independence.

Remedies for Allergy Eyes

Fri, 12 Jun 2009 06:00:00 CDT

Do your eyes turn red and itchy every spring and summer? It could be allergic conjunctivitis – a treatable, but uncomfortable allergy condition.

Allergic conjunctivitis is a common cause of red, itchy eyes. Although allergies are best known for causing nasal symptoms, they also can be irritating to the eyes. In allergic conjunctivitis, the affected part of the eye is the conjunctiva, the thin, elastic tissue that covers the white of the eye and lines the inside of the eyelid. Fortunately, doctors and patients have an array of therapies at their disposal to prevent or treat allergic conjunctivitis.

Conjunctivitis can be caused by either allergies or infection. In allergic conjunctivitis, the eyes become red and itchy, with a watery, stringy, or ropelike discharge. Both eyes are usually affected. In addition, people with allergic conjunctivitis often have a history of allergic rhinitis, asthma, or eczema. Infectious conjunctivitis also leads to eye redness but is more likely to produce tearing and discharge in one or both eyes. People with these symptoms may need antibiotics and should see an eye doctor.

Allergic conjunctivitis can be seasonal (occurring only at specific times of the year) or perennial (occurring year-round). Seasonal allergic conjunctivitis is typically caused by outdoor allergens, such as pollen, and the perennial form is usually caused by indoor allergens, such as cockroaches, dust mites, or pet dander. Skin or blood testing by an allergist can pinpoint a patient’s specific triggers.

Treatments for allergic conjunctivitis
To prevent symptoms of allergic conjunctivitis, patients should learn to avoid or limit their exposure to triggering substances. When symptoms do erupt, cold compresses on the eyes may help relieve conjunctivitis symptoms in the short term.

Medications are a mainstay of treatment for allergic conjunctivitis. Some doctors recommend using artificial tears, which provide a barrier between allergens and the eye; they also help dilute and flush out the allergens that contact the eye. Other conjunctivitis medications include:

Antihistamine eyedrops -- for acute treatment of ret, itchy eyes

Oral antihistamine medication -- to reduce itchy eyes

Vasoconstrictors -- for short-term treatment of redness and swelling

Nonsteroidal anti-inflammatory eyedrops -- for reducing symptoms in some patients

Mast-cell inhibitors -- to treat a range of symptoms, including itching, swelling, and watery eyes

Doctors usually prescribe corticosteroid eyedrops only for severe cases of allergic conjunctivitis and only for short periods because of the risk of side effects, including cataract and elevated eye pressure, which may lead to glaucoma. For some conjunctivitis patients, allergy shots may be a useful way to prevent allergies from recurring.

How Floaters and Flashers May Signal a Detached Retina

Fri, 22 May 2009 06:00:00 CDT

From time to time nearly everyone experiences floaters -- small dots, lines, clouds, or "cobwebs" across the visual field. This phenomenon is caused by shadows cast on the retina by microscopic structures within the vitreous humor (a thick, gel-like substance that fills the back of the eyeball behind the lens). In most cases, flashes and floaters are harmless, but they may they indicate that the retina (the innermost layer of the eye that consists of light-sensitive nerve tissue) is tearing or in danger of detaching from the underlying layers of the eyeball. Detached retina may be a medical emergency that can result in blindness.

As you edge over age 40, the vitreous -- the clear gel-like substance inside your eyes -- begins to liquify and shrink. Within the gel are millions of fibers attached to the retina, the light-sensitive nerve tissue lining the interior of the eye. As the gel shrinks, the fibers break, allowing the vitreous to peel away from the retina, a process called posterior vitreous detachment (PVD).

Most of the time, the development of a PVD doesn't cause any problems for eye health, and typically no treatment is needed. When a PVD occurs you may develop floaters that move or swim as you move your eyes.

Many older people get floaters without PVD. But their sudden appearance or an increase in the number of typical floaters may announce PVD, as may flashes of light. These arise as the separating vitreous tugs on the retina, stimulating cells that send a message of light to the brain. In some cases, this pulling may break a blood vessel on the retina, resulting in what's called a vitreous hemorrhage.

To check for PVD, an eye doctor will dilate your pupil with eye drops and use a special lens to see the vitreous and the retina. If you do have PVD, often the physician will see a ring of the vitreous fibers floating in the vitreous cavity (a Weiss ring). This represents the site where the vitreous was formerly attached to the retina.

In 10-15% of people who have PVD with symptoms, some of the vitreous fibers pull so hard as they naturally separate from the retina that they create a tear or hole, especially in the thin retinal peripheral tissue. Vitreous fluid then has the opportunity to leak through the tear, which can cause the retina to detach from the back wall of the eye. This is a sight-threatening situation: If the tear is not repaired, the retina can detach completely.

Bottom line: Although you can't prevent or treat PVD, you can try to prevent its repercussions by alerting your doctor at the first sign of floaters, flashes of light, or any change in side vision. It is usually possible to repair a retinal tear, but a tear can also evolve quickly to retinal detachment. So don't wait to see whether floaters discontinue when you suddenly begin to notice lots of them. Even if no retinal tear appears, your doctor can help you stay alert for that possibility.

Steps to Help You Avoid Medication Mistakes

Fri, 10 Apr 2009 06:00:00 CDT

When you consider how many different medications many of us take every day, it's not surprising that mistakes happen. According to a report from the Institute of Medicine, some 1.5 million preventable adverse drug events occur in the United States every year. As dire as this sounds, there is much you can do to avoid medication errors. Here are some tips from Johns Hopkins.

If low vision makes it difficult for you to read labels, discriminate between similarly shaped pills, and read the information sheets that come with medications, or if memory problems hinder your ability to remember when to take medication, you can still avoid adverse drug events by trying some of these helpful tips:

If You Have Vision Loss:

Use a medication organizer or "dosette" to keep track of your pills, and put larger-type labels on each compartment so that you can read the days of the week and the times of day. Ask a family member or friend to fill the medication organizer for you each week.

Keep a magnifier handy with your pills.

Ask your pharmacist to use different-size bottles when dispensing similarly shaped pills. Or ask about talking pill bottles. They play a recorded message telling you the name of the medication and your prescription information.

If You Have Memory Loss:

Try wrapping rubber bands around each pill bottle equaling the number of daily doses. Remove one band each time you take the medication, and then replace all of the bands for the following day.

Keep a medication chart in order to record whether you have taken your pills. This can be a simple dry-erase board on the refrigerator door; put a check next to each medication after you take it.

Use an alarm on your watch or cell phone to remind you when it's time to take your medication. Some fancier versions of dosettes come with built-in alarms. There are even automated medication dispensers that announce when it's time to take your medication, then dole out the appropriate pill.

Slowing the Progression of Diabetic Retinopathy

Fri, 20 Mar 2009 06:00:00 CST

It is estimated that 70% of people with type 2 diabetes will eventually develop diabetic retinopathy. If you have diabetes, you should know that there are steps you can take to prevent diabetic retinopathy from developing or to slow its progression. Johns Hopkins provides advice.

About 21 million Americans have diabetes, a condition characterized by abnormally high levels of glucose (sugar) in the blood. Although no cure exists for diabetes, blood glucose levels can be controlled by carefully following a program of diet, exercise, and (if necessary) medication.

High blood glucose levels can damage small blood vessels in the retina, a condition called diabetic retinopathy. Diabetic retinopathy affects more than 4.1 million Americans age 40 and over and is more common in people with poorly controlled diabetes. One out of 12 people over age 40 with diabetes has diabetic retinopathy severe enough to cause vision loss.

If you have type 1 or type 2 diabetes, you can take several steps to prevent diabetic retinopathy from developing or to slow its progression. Precautions include getting regular eye examinations and keeping your blood glucose and blood pressure under tight control. Blood glucose levels are considered well controlled when levels of hemoglobin A1c (used to measure blood sugar levels over time) are less than 7%.

Two large studies have proven the benefits of controlling blood glucose levels when it comes to eye health. In the Diabetes Control and Complications Trial, people with type 1 diabetes who gave themselves multiple insulin injections each day to attain a hemoglobin Alc level of 7% reduced their risk of developing diabetic retinopathy by 76% and the risk of their diabetic retinopathy getting worse by 54%, compared with people who followed a less rigorous treatment regimen.

In the United Kingdom Prospective Diabetes Study, people with type 2 diabetes maintaining a hemoglobin Alc level of 9% who controlled their blood glucose levels with medication were 30% less likely to have diabetic retinopathy that required laser treatment than people who relied on diet and exercise alone. As for lowering blood pressure, a recent study found that every 10-mm Hg reduction in systolic blood pressure (the top number) decreased the incidence of diabetic retinopathy and other diabetic complications by 12%.

Coping With Dry Eye

Fri, 27 Feb 2009 06:00:00 CST

If you're one of the approximately five million Americans who suffers with dry eye syndrome, you know if can affect everything you do – even driving. Now a report in the American Journal of Ophthalmology takes a closer look at this troublesome, but often overlooked condition.

Dry eye affects quality of life. That's no surprise to people who have dry eye syndrome, a condition that affects the amount of tears produced as well as the quality of the tear film that covers the front part of the eye.

In a study reported in the American Journal of Ophthalmology (Volume 143, page 409), researchers reviewed questionnaire responses from 690 participants, age 49 or older, in the Women's Health Study and the Physicians' Health Study, a third of whom were identified clinically as having dry eye or severe symptoms of dry eye.

They found that people with dry eye syndrome who were not using artificial tears had five times as many difficulties with everyday tasks as those without dry eye syndrome. Although individuals with dry eye syndrome who were using artificial tears had some improvement, these individuals still reported three times as many difficulties with everyday tasks as those without dry eye syndrome. Also of concern are the possible effects of dry eye syndrome on vision while driving: a reduced ability to see contrasts, an increased sensitivity to glare, a fluctuating clarity of vision.

Currently, dry eye syndrome affects almost five million people age 50 or over in the United States. And yet, according to this study, because dry eye doesn't lead to blindness, doctors may overlook its potentially serious effect on day-to-day life. If your eyes feel dry, tired, and irritated or if your vision seems unstable, see your eye doctor so he or she can determine if you have dry eye syndrome and help minimize its effect on your daily life.

Are You an Eyedrop Dropout?

Fri, 06 Feb 2009 06:00:00 CST

On your daily list of things to do, seeing your eye doctor and taking your glaucoma medicine might not be a high priority, especially if you're not experiencing any symptoms. According to several recent studies, many people who have just learned they have glaucoma or who are suspected of having it fail to keep up with recommended guidelines for follow-up appointments and treatment. This is disturbing news, given that early identification and treatment of glaucoma can slow the progression of this potentially blinding disease.

Q. My doctor prescribed eyedrops for glaucoma. Will I have to use them for the rest of my life?

A. Most likely, yes.

Glaucoma is a chronic condition that cannot be cured. It occurs when the fluid in the eye, the aqueous humor, is not draining properly, raising the intraocular pressure (IOP) high enough to begin to damage the optic nerve.

The most common form, open-angle glaucoma, progresses slowly and can be detected through eye exams before a patient is aware of any glaucoma symptoms. The purpose of the eyedrops your doctor recommends is to lower the IOP and keep it at a level that prevents damage to the optic nerve and visual field, usually at least 25% below the level at your diagnosis.

Most people with glaucoma have to use eyedrops from one to four times a day, depending on the type of drop. In some cases, it may be necessary to use one or several different types of drops simultaneously. Although some people take oral medications for glaucoma, those tend to have side effects, such as numbness or tingling in the hands and feet, depression, or loss of appetite. Doctors tend to prescribe oral medications for glaucoma only if the IOP can't be controlled by drops.

Laser trabecular surgery or filtration surgery are also options if medications don't work. However, after surgery, you would still likely need to use daily drops, although at a lower dose.

The Causes of Double Vision and What You Can Do About It

Fri, 26 Dec 2008 06:00:00 CST

Double vision, or diplopia, is not the same as blurry vision. People who have double vision see two distinct clear images of a single object, rather than one blurred image. Seeing double can interfere with even the simplest of activities and make complicated tasks impossible. In this Health Alert, Johns Hopkins Professor Susan B. Bressler, M.D. discusses the causes and treatment options of double vision.

There are two types of double vision -- binocular and monocular. Binocular double vision is present only when both eyes are open. The double vision disappears if either eye is closed. Binocular double vision is caused by problems with the extraocular muscles that control the eyeball or the nerves that signal these muscles. If the eyeballs aren’t correctly aligned and moving in synchrony with one another, the images generated from each eye are focused on a different point and don’t match up. Double vision is the natural result.

According to Susan B. Bressler, M.D., Professor of Medicine in the Department of Ophthalmology at Johns Hopkins, the two most common causes of binocular double vision in people over 50 are thyroid conditions, such as Graves’ disease, and cranial nerve damage. Graves’ disease can affect the extraocular muscles directly. In most cases, however, underlying nerve damage causes the extraocular muscles to malfunction. Multiple sclerosis, a brain tumor, head trauma, or stroke can all damage the cranial nerves, but the most common cause is diminished blood flow due to high blood pressure or diabetes.

Monocular double vision is present with both eyes open but, unlike binocular double vision, persists when the problematic eye is open and the contralateral (fellow) eye is closed. Monocular double vision is caused not by misalignment, but rather by problems in the eyeball itself. Astigmatism, dry eye, and some retinal problems or certain cataracts can all cause monocular double vision.

Getting Treatment for Double Vision -- Some cases of double vision resolve after a change of eyewear prescription. Binocular double vision may be treated with prisms incorporated into glasses or with an eye patch. If the condition doesn’t improve using these measures, surgery may be considered. Monocular double vision is addressed by treating the underlying condition, using anything from eyedrops (for dry eyes) to surgery (for cataracts).

Bottom line on double vision: Over time, binocular double vision may seem to go away on its own, as the brain eventually learns to suppress one of the mismatching images to avoid seeing double. While the symptom of double vision improves, you may still be suffering from whatever condition caused the double vision in the first place. If you’re experiencing double vision, make an appointment with an ophthalmologist as soon as possible. With so many possible causes, the sooner you seek help, the better your chances of seeing clearly in the future.

Cataract Surgery and Macular Degeneration

Fri, 05 Dec 2008 06:00:00 CST

Cataract surgery is the most commonly performed surgical procedure in the United States. More than 1.5 million cataract operations are performed each year. In this Health Alert Johns Hopkins answers the question: Will cataract surgery worsen my age-related macular degeneration?

A cataract is an opacification (cloudiness) of the eye's normally clear crystalline lens. Derived from the Latin word meaning waterfall, the term "cataract" arose from the ancient misconception that evil liquids flowing into the eye were the cause of cataract symptoms.

Cataracts can occur at any age (in fact, babies can be born with cataracts), but cataracts are most common later in life. In the United States, 75% of people over age 60 have some sign of cataracts. It is estimated that more than 20 million Americans over age 40 (approximately 17%) have had a cataract. That number is anticipated to reach about 30 million by the year 2020.

Q. Is it true that cataract surgery might worsen my age-related macular degeneration?

A. So far, no evidence proves that cataract surgery worsens age-related macular degeneration. The suggestion that it might arose largely from several small studies and the large Beaver Dam Eye Study, which found that advanced age-related macular degeneration developed more often in eyes that had cataract surgery than in those that did not. Researchers speculated that perhaps inflammation from the surgery spurred the progression of age-related macular degeneration.

Another theory suggested that the replacement lens inserted in the eye during cataract surgery did not protect the eye from "blue light," light waves that may increase the risk of age-related macular degeneration. But neither of those theories has panned out.

Some researchers suspect that many of the people had undetected age-related macular degeneration at the time of the cataract surgery, which may have been causing their vision problems.

A cataract can obscure a detailed view of the retina, making it difficult to identify subtle features of advanced age-related macular degeneration The seven-year Age-Related Eye Disease Study (AREDS), which involved 4,700 people, found no link between cataract surgery and a progression from dry age-related macular degeneration to the more severe wet form.

7 Tips To Help You Cope With Vision Loss

Fri, 14 Nov 2008 06:00:00 CST

Dealing with vision loss is challenging. For people with glaucoma, macular degeneration, or another vision problem, low-vision aids can help optimize remaining vision and improve the ability to perform daily activities.

Some examples of low-vision aids are telescopes, closed-circuit televisions (a small television camera is mounted on a movable tray; documents or other objects are moved under the camera and viewed on a small monitor), magnifying glasses, clocks and phones with large numbers, and large-print reading materials. Telescopes and closed-circuit televisions require an evaluation and prescription from an eye care professional as well as training in how to use them.

Many low-vision aids are available through low-vision clinics and low-vision rehabilitation services. Researchers are also testing implantation of a miniature telescope into damaged eyes.

Mild vision impairment has little effect on day-to-day activities, but moderate to severe vision impairment can make it difficult for people to perform common household tasks. Ophthalmologists and low-vision counselors recommend these simple, practical strategies to help patients with low vision maintain their independence.

Always leave doors completely open or completely closed. This reduces the risk of accidentally walking into the door edge if you have low vision.

Tack down loose rugs and use non-slip mats beneath them. Or you can hold down rugs with furniture to prevent slipping and tripping.

Tape a colorful piece of paper to all clear glass doors. If you have low vision, this will help you determine whether the door is open or closed and prevent collisions.

Avoid using glass-topped coffee or end tables. The edges are extremely difficult to see, making bumping injuries more likely if you have low vision.

Mark the important settings on the dials of the stove, washer, dryer, and other appliances using brightly colored tape.

Mark the outer edge of all indoor and outdoor stairs. Use a strip of paint or non-skid material in a color that contrasts with the rest of the step. The strip should extend about two inches from the edge -- both horizontally and vertically -- and should go across the full width of the step. This reduces the chances of tripping or falling on the stairs if you have low vision.

Have someone help you arrange clothing if you have color-vision problems. Separate items according to color and then use labeled dividers to identify them.

How Do You Know When It's Time For Cataract Surgery?

Fri, 24 Oct 2008 06:00:00 CDT

Cataracts form painlessly. The most common cataract symptom is cloudy or blurry vision. Everything becomes dimmer, as if seen through glasses that need cleaning. Surgery is the only way to cure cataracts, but surgery is not always necessary. Some people can improve their vision with lifestyle changes. In this Health Alert, Johns Hopkins answers the question, "How can you tell it's time to undergo cataract surgery?"

Cataracts cause cloudy, even double vision, and a problem with glare. At first, many people can switch eyeglass prescriptions, use magnification, and add to their home lighting to address any loss of vision. But it's time to consider cataract surgery when changes in vision begin to interfere with day-to-day activities such as driving and reading. In that sense, the decision is personal, and in most cases, you won't harm your vision by taking your time to decide.

However, in young people or in those with diabetes, a cataract can develop rapidly, making the need for a decision more immediate. In other cases, cataracts may interfere with the treatment of another eye problem such as age-related macular degeneration, diabetic retinopathy, or retinal detachment. In those cases, the cataract may need to be removed to allow effective treatment of a retinal disorder, even if the cataract is not con- tributing to the vision deficit.

Before recommending cataract surgery, your eye doctor will ask you about functional difficulties you may be having with reading, driving, or other activities and measure your visual acuity. Your doctor may also test your eyes for loss of contrast sensitivity or the effects of glare. In addition, he or she may ask you to complete a quality-of-vision questionnaire to help assess your ability to do different daily tasks like reading. Your answers and the results from these tests can help determine whether it's time to consider cataract surgery.

Need Reading Glasses? Perhaps You Should You Try Multifocal Contact Lenses.

Fri, 12 Sep 2008 06:00:00 CDT

If you've reached your mid-40s or beyond, you're likely to experience difficulty focusing on tasks at a close distance such as reading fine print. More likely than not, you need "reading" glasses. The problem is particularly exasperating if you already use glasses or contact lenses to correct your distance vision. If you don't want to wear bifocal spectacles or reading glasses on top of your contact lenses or to have separate prescriptions for distance and near vision, multifocal contact lenses offer an attractive alternative.

Multifocal contact lenses correct both distance and near vision by including two or more prescriptions in one lens. Most multifocal contact lenses are available as ordinary soft contacts lenses or as rigid gas permeable (GP) contact lenses that allow oxygen to pass through them, much as silicone hydrogel soft lenses do. There are two types of multifocal contact lenses: translating and simultaneous vision.

Translating contact lenses. These contact lenses resemble bifocal glasses, with a line separating the distance prescription on top from the near-vision prescription below. A third prescription for intermediate distance (for instance, the working distance from a computer) also can be added, making them similar to trifocal spectacles.

The advantage of translating contact lenses is that they stay in place when you blink because they are weighted at the bottom. To use the near-correction prescription, you simply lower your gaze. The drawback is that because they're made of a more rigid material than traditional soft lenses, they may not be comfortable initially.

Simultaneous contact vision lenses. These contact lenses enable you to look through the distance and near powers of the contact lenses simultaneously. The lenses may be concentric or aspheric in design.

Concentric lenses. Contact lenses with this pattern have one vision prescription in a ring at the center, which is surrounded by larger rings that alternate between the near and distance prescriptions. An additional ring can be added to improve vision at intermediate distances.

Aspheric lenses. With these contacts lenses, both the near and distance prescriptions are placed on or close to your pupil. When you look at something that is far away, your eyes learn to ignore objects that are close by. Conversely, when you focus on an object that is close, your eyes learn to ignore things that are far away. The challenge is to learn to pick the part of the lens you need from moment to moment.

What's best? The best type of contact lenses for you depends on the size of your pupils and the strength of your near-vision prescription. You may have to try several kinds to find the one that's most comfortable.

Low Vision Patient Resources

Fri, 22 Aug 2008 06:00:00 CDT

Do you have trouble reading the newspaper even with your glasses on? Do you often bump into things? Do you have trouble moving about at night? When you pay with cash, is it hard to read the denomination on the bill? If you answered “yes” to any of these questions, you may have low vision. Here's advice you can use.

Performing household chores, reading, driving, recognizing the face of a family member -- daily activities that the average person takes for granted -- are tasks that can be difficult to accomplish when you have low vision. But vision rehabilitation specialists can teach you new ways to complete these and other day-to-day tasks, often with the aid of low-vision devices, such as magnifiers, electronic reading systems, and specially adapted computers.

Although Medicare has covered low-vision services performed by an ophthalmologist, optometrist, or occupational therapist since 2002, the number of service providers is limited, leaving many people without needed help. The Low Vision Demonstration Project offers some relief by expanding Medicare’s coverage to include services provided by low-vision therapists, orientation and mobility specialists, and vision rehabilitation therapists.

These specialists must work under the supervision of an ophthalmologist or optometrist, and they must be certified by the Academy for Certification of Vision Rehabilitation and Education Professionals (ACVREP). Although these changes represent a major step forward in meeting the needs of people with low vision, the major shortcoming -- at least for now -- is that the projects are limited to people who reside in one of the six demonstration sites: Kansas, New Hampshire, North Carolina, Washington state, New York City (all five boroughs), or Atlanta, Georgia.

If you live in one of the six areas involved in the project, contact your local Medicare office and ask how to take advantage of the program. The National Council of Private Agencies for the Blind and Visually Impaired (www.ncpabvi.org; or call 866-645-2449) can also identify participating agencies in each area.

If you do not live in one of the six demonstration areas, low vision rehabilitation services are available but be aware that some may not be covered by Medicare or private insurance. Your eye doctor is a good resource for the rehabilitation services in your area.

Another option is to go to www.visionconnection.org to use the “VisionConnection Help Near You Locator,” which was put together in partnership with the American Academy of Ophthalmology, the American Optometric Association, and Lighthouse International. The locator will help you find low-vision rehab professionals nearby. Another resource is the American Foundation for the Blind website (www.afb.org), which lists low-vision service organizations in each state.

LASIK Surgery Safe and Effective, Even at Middle Age and Beyond

Fri, 01 Aug 2008 06:00:00 CDT

Considering LASIK eye surgery? The good news is that middle-aged patients in their 60s respond well to this popular vision correction surgery. Here's what the experts report.

Laser eye surgery is not just for the young. It can also help people in their 40s, 50s, and 60s who have presbyopia (an inability to focus on near objects), according to a recent study reported in the journal Ophthalmology (Volume 114, page 1303 ).

The researchers examined 710 eyes of 424 people between the ages of 40 and 69 after LASIK surgery. About half of the people had undergone a monovision correction: One eye was corrected to see distant objects (such as those seen while driving) and the other eye was corrected to see near objects (for example, reading).

To compensate for the less vigorous healing that comes with age, the surgeons modified the technique slightly based on the person’s age. After surgery, 80–100% of the eyes (depending on the age group) had 20/30 vision without the use of corrective lenses. No one lost more than two lines of best-corrected vision on the standard vision chart, and only nine eyes lost two lines of vision that could not be corrected with glasses or contact lenses. Vision correction without eyeglasses was not quite as good for those in their 60s compared with the younger groups, and the older individuals were more likely to need a repeat procedure, but the differences between groups weren’t significant.

If you’re over 40 and thinking about laser eye surgery, go ahead and talk with your doctor. Your eyes are likely to do almost as well as those in the younger set.

Soothing Dry Eye

Fri, 11 Jul 2008 06:00:00 CDT

Blink! Feel better? Every time you blink, you refresh the layer of tears that covers and protects your eyes from irritants and infection. If your body fails to produce enough tears or produces less-than-perfect tears, your eyes can burn and feel itchy, gritty, or irritated -- like you have an eyelash or dust in your eye. This condition is called dry eye and affects millions of Americans.

Dry eye rarely causes blindness, but dry eye can affect the quality or sharpness of vision; also, living with constant eye fatigue and irritation can raise stress levels and limit activities like reading and driving. In rare instances, if severe dry eye isn’t treated, scarring can occur and can affect vision -- especially if it’s located in the central cornea.

Artificial tears are the primary treatment for dry eye. They are sold over-the-counter; some contain preservatives, some do not. The preservatives found in artifical tears won’t harm your eyes, but they may irritate the eye’s surface. If you experience a lot of burning, you might try switching to nonpreservative formulations. Preservative-free teardrops contain fewer chemicals, but they are only available in single-use applications and, as a result, are more expensive than tears with preservatives. There are also thicker gel lubricants that stay on your eye longer. Your ophthalmologist can help determine which product is best for you.

A prescription medication called Restasis (cyclosporine) was approved to treat dry eye in 2004; it reduces inflammation on the surface of the eye, but it doesn’t work for everyone with dry eye. Sometimes, the use of mild steroid drops for short periods of time also can be effective. However, steroids used for long periods can increase the risk of glaucoma and cataracts.

Tears drain into channels at the corner of your eye that empty into your nasal cavity. If artificial tears and prescription medications don’t adequately alleviate symptoms, your eye doctor can block the tear drainage system in at least one eye either temporarily or permanently with silicone plugs or other techniques. This procedure is called punctal occlusion.

A note of warning: Using over-the-counter eyedrops that “get the red out” may aggravate your dry eye condition. If your eyes are red and irritated from dry eye, artificial tears will help offer relief, whereas these other types of eyedrops “bleach” the so-called white of your eye by constricting ocular blood vessels, and this may contribute to your symptoms.

Treating Women With Glaucoma

Fri, 30 May 2008 06:00:00 CDT

Are you receiving optimal treatment for your glaucoma or other eye condition? A study in Ophthalmology shows that often women and younger people are less likely to get glaucoma treatment than men.

Most forms of glaucoma are chronic conditions that cannot be cured. Open-angle glaucoma can often be treated safely and effectively with medication or surgery, but lifelong use of medication is almost always necessary. Decisions on when to start treatment are based on the amount of optic nerve damage and visual field loss, as well as risk factors such as elevated intraocular pressure, increasing age, and black or ethnic background.

Acute closed-angle glaucoma is a medical emergency. If you have symptoms of closed-angle glaucoma (severe pain in the eye, nausea and vomiting, blurred vision, and rainbow-colored halos around lights), contact your ophthalmologist immediately.

Unfortunately not everyone receives the same level of treatment for glaucoma, according to a study in the journal Ophthalmology (Volume 112, page 1494). The study observes that women and younger people are much less likely to receive glaucoma treatment than older men.

Researchers looked at who received treatment with either surgery or medication from a cohort of patients that included 35,754 people suspected of having glaucoma, 5,265 diagnosed with glaucoma, and 2,633 with signs of early glaucoma.

What they found was that treatment in people with glaucoma or suspected of having glaucoma was initiated less often in women, especially if they were younger and not followed-up at their doctor’s office. Other variables associated with greater likelihood of treatment were having a diagnosis of glaucoma and the region of the country where the patients were treated.

Women were 24% less likely to be treated for glaucoma than men, and younger people of both sexes were far less likely to be treated than older people. Since the reasons for the disparity in treatment are unclear, the authors note that understanding the sources of variation in treatment will improve treatment for people with glaucoma or suspected of having glaucoma.

Diabetes and Cataract Surgery

Fri, 09 May 2008 06:00:00 CDT

For people with diabetes, cataract surgery poses serious risks, as a recent British study explains.

Surgery for cataracts involves removing all or part of the lens and replacing it with an intraocular lens implant (IOL). Cataract removal is the most frequently performed surgery in people over age 65 and is considered by many doctors to be the most effective surgical procedure in all of medicine. If the eye is normal except for the cataract, surgery will improve vision in more than 95% of cases.

Cataract surgery is remarkably safe. Significant post-surgical complications, such as inflammation, infection, bleeding, swelling, retinal detachment, and glaucoma are rare: They occur in only 1-2% of people. People with other eye diseases and serious medical problems are most at risk for complications.

For example, cataract surgery in diabetics is often followed by complications such as macular edema, retinopathy, and iris neovascularization (abnormal blood vessel growth in the iris). In a recent British study, reported in the British Journal of Ophthalmology (Volume 90, page 697), researchers were able for the first time to correlate such outcomes with a rise in levels of blood vessel growth factors following cataract surgery.

The researchers used fluorescein angiography, an eye test that uses orange dye and a camera to take pictures of the retina, and measured growth factor levels in water-based samples taken from six diabetic patients before cataract surgery and three times following cataract surgery, on days one, seven, and 90.

In four patients, retinopathy in the macula, the center of the retina, worsened. Levels of two factors that promote blood vessel growth -- vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) -- also increased significantly. A different growth factor -- pigment epithelial derived growth factor (PEGF), which discourages new blood vessels from forming -- decreased after cataract surgery. An inflammatory chemical messenger called interleukin 1B also increased, which is normal after cataract surgery but can stimulate the release of VEGF and HGF. The next step, researchers say, is to study whether new anti-VEGF treatments ranibizumab and bevacizumab can control growth factor levels following cataract surgery.

Reeling in Fatty Fish for the Eyes

Fri, 28 Mar 2008 06:00:00 CST

The importance of omega-3 fatty acids, found in fatty fish and other foods, in heart disease prevention is well documented. Now new research suggests that eating oily fish can help slow or prevent age-related macular degeneration. Read what the experts have found.

The causes of both non-neovascular (also known as nonexudative, atrophic, or dry) and neovascular (also called exudative or wet) age-related macular degeneration are unknown, although there are known risk factors for both forms of the disease. Increasing age, farsightedness, cigarette smoking (and possibly exposure to secondhand smoke), a light-colored iris, obesity, and a family history of the disorder all raise the risk of both types. In addition, high blood pressure appears to be linked to a greater risk of neovascular age-related macular degeneration, as are high levels of C-reactive protein a marker of inflammation in the body.

Is there anything you can do to protect your eyes against age-related macular degeneration? Recent studies that appeared in the Archives of Ophthalmology (Volume 124, pages 981) points to fish oil as a potent anti-inflammatory, protecting high-risk individuals against age-related macular degeneration.

Eating oily fish like salmon, herring, tuna, and mackerel one to three times a week appears to cut the risk of age-related macular degeneration, according to two recent studies. In a study at the University of Sydney Eye Clinic in Australia, researchers followed nearly 3,000 men and women for five years. Those who ate fish once a week had a 40% reduced risk of early age-related macular degeneration compared with those who ate fish only once a month; those who ate fish three times a week had a reduced risk of late age-related macular degeneration.

In another study of almost 700 male twins by researchers at the Massachusetts Eye and Ear Infirmary and Harvard Medical School, those who ate fish at least twice a week lowered their risk of age-related macular degeneration by 45% compared with people who ate fish less than once a week. Researchers believe the protection stems from the omega-3 fatty acids that are plentiful in oily fish. Other studies have shown that omega-3s reduce inflammation that results from free radicals, molecules that damage healthy cells, including those in the retina.

How Common Diseases Affect The Eyes

Fri, 18 Apr 2008 06:00:00 CDT

The eye is a made up of numerous parts that work together to make vision possible. Here is a brief introduction to the anatomy of the eye and an explanation of four common eye diseases that afflict many of us.

How does the eye work? When you look at something, you are able to see it because the surface of the object reflects light rays. These rays pass sequentially through the cornea, the pupil, and the lens of your eye. The cornea and the lens focus the light rays onto a precise point on the retina (the fovea). Light-sensitive cells within the retina translate the patterns of light into chemical signals that are conveyed to the brain via impulses in the optic nerve. In essence, the eye works in much the same way that the lens of a camera focuses light onto film. The sclera, the conjunctiva, and the choroid are tissues that protect and nourish the eye. Diseases of the eye can perturb this process at many different points to interfere with vision. The four most common causes of blindness and vision loss are:

Eye Condition 1: Cataract. A cloudy or opaque area in the lens can interfere with its ability to transmit light rays from the front of the eye to the back of the eye. This can cause cloudy or filmy vision, the appearance of halos around lights, and loss of contrast or brilliance of colors.

Eye Condition 2: Glaucoma. Buildup of aqueous humor, a fluid that occupies the space between the cornea and the lens, can damage the optic nerve by increasing pressure within the eye, often because its normal drainage is blocked. The result is loss of side vision and, eventually, of vision directly in the center, with poor visual clarity and, if the problem is not treated effectively, gradual blindness.

Eye Condition 3: Age-related macular degeneration (AMD). The macula, the central part of the retina, is responsible for central (as opposed to peripheral) vision and for perception of detail and colors. In the less common and more severe type of AMD, called neovascular or “wet” AMD, abnormal blood vessels from the choroid grow and may bleed and leak fluid under and within the macula. As they heal, they typically leave scars that prevent the macula from functioning well. More common is the non-neovascular or “dry” form of AMD, in which deposits called drusen collect under the retina and may lead to thinning or loss of retinal cells. This can result in blank spots in the central vision.

Eye Condition 4: Diabetic retinopathy. Some people with diabetes gradually develop damage to small blood vessels in the retina, which can lead to leakage of fluid and swelling of the macula. This itself can blur vision in the eye. In advanced stages, fragile blood vessels grow from the retina into the vitreous humor in the back of the eye. These may bleed and form scar tissue, which can eventually cause the retina to detach, leading to blindness. Adequate blood sugar control can minimize this damage and may prevent its progression.

Experimental Treatments for Age-Related Macular Degeneration

Fri, 15 Feb 2008 06:00:00 CST

Scientists look to human stem cells to enable the retina to repair itself.

Several new treatments that may help prevent vision loss in people with age-related macular degeneration are under investigation. Besides continuing development of treatments to prevent new blood vessel growth as well as leakage from blood vessels in the eye, researchers are also studying drugs known as angiostatic corticosteroids (such as anecortave acetate, tramcinolone, and flucinolone), sometimes in conjunction with other treatments such as photodynamic therapy.

What’s on the horizon? Human retinas damaged by diseases, such as age-related macular degeneration and diabetic retinopathy, are unable to repair themselves. But now in a report from the National Academy of Sciences (Volume 103, page 12769 ), researchers at the University of Washington and elsewhere suggest that the regeneration of damaged cells in the retina may someday be possible. Their optimism is based on successful treatment of diseased retinas in mice using human stem cells.

The University of Washington scientists first grew human embryonic stem cells (from a cell line approved in the United States) in a lab, then added growth factors -- proteins that enable cell growth -- central to the development of both human and mouse heads as well as a growth factor essential to a frog’s sprouting of large eyes. Within two weeks -- twice as fast as human cell development -- the embryonic cells became progenitor (forerunner) cells for retinal cells. The scientists injected these into a damaged mouse retina, where they developed into cones (the retinal cells responsible for color), rods (the cells that allow night vision), and other cells.

The scientists' next step will be to measure the nerve reactions within the repaired mouse retinas to see if vision has improved. If the research proceeds well, the researchers speculate that human tests might begin in two to three years.

Cornea Thickness and Glaucoma

Fri, 25 Jan 2008 06:00:00 CST

Are you at risk for glaucoma? Hopkins specialists explain this common eye condition and report research that links cornea thickness with severity of the glaucoma.

Glaucoma occurs when the clear liquid in the front of the eye, called the aqueous humor, places enough pressure on the optic nerve to damage it. Often this damage is caused by elevated pressure within the eye, but in some cases normal pressure damages the nerve.

Internal pressure in the eye, or intraocular pressure (IOP), is primarily regulated by the aqueous humor. Continually manufactured by the ciliary body (a ring of tissue that is located behind the iris), aqueous humor flows through the pupil into the anterior chamber. After delivering nutrients to the lens and cornea, the fluid drains from the eye through a spongy network of connective tissue known as the trabecular meshwork. From these tiny channels, the fluid passes into a larger opening and eventually drains into the veins of the sclera (episcleral veins) for disposal.

Normally, the steady production and drainage of aqueous humor maintain a stable balance of fluid in the eye and keep IOP within a safe range. Open-angle glaucoma caused by high IOP may develop when, for unknown reasons, the trabecular meshwork becomes partially blocked, hindering the outflow of aqueous humor and throwing off the eye’s fluid balance.

A study reported in the Archives of Ophthalmology (Volume 122, page 17) reveals that the thickness of the cornea is strongly correlated with the severity of the glaucoma. Researchers examined medical records that contained information on 190 patients and 350 eyes afflicted by glaucoma. They found that patients with thinner corneas consistently had worse cases of glaucoma and greater eye damage than those with thicker corneas. Corneal thickness was not, however, associated with the number of glaucoma medications taken by patients.

This study was the first to demonstrate that thinner corneas are predictive of more severe glaucoma. In addition, family history of glaucoma was associated with worse disease. The authors concluded that measuring corneal thickness may help ophthalmologists identify patients who are at higher risk for developing severe glaucoma-related problems and prompt them to treat their glaucoma more aggressively.

Silencing Genes To Halt Age-Related Macular Degeneration

Fri, 04 Jan 2008 06:00:00 CST

Can interfering with RNA shut down the macular degeneration process?

Imagine that age-related macular degeneration had an off switch. In fact, researchers may have found one for the most severe stage of age-related macular degeneration, by shutting down the genes that control vascular endothelial growth factor (VEGF). This molecule plays an important role in the abnormality known as wet (neovascular) age-related macular degeneration, in which new blood vessels grow under the retina.

Several biotechnology firms have succeeded in switching off blood-vessel growth using a technique that scientists call RNA interference, or RNAi. The common term for the process is more descriptive: gene silencing. The scientists who worked out the details of this process of RNA interference won the Nobel Prize for Physiology and Medicine in 2006.

RNA is a chemical responsible for translating the genetic code within DNA into proteins, the molecules that are the basis for cell structure and molecular signaling between cells. Most of the time, RNA exists in a single strand. But when RNA appears in a double strand (one RNA strand matching the other as a chemical mirror image), cells destroy it and any other RNA like it. This process may have arisen to guard against viruses, which sometimes create double-stranded RNA.

Eventually, the process of RNA interference may prove useful against diseases such as cancer, AIDS, and hepatitis. But age-related macular degeneration has proven an easier target, partly because researchers already know some genes to block, such as the ones that control VEGF production. Also, although it is a major challenge to deliver siRNA to the right cellular target in diseases that affect the entire body, in the case of age-related macular degeneration this is straightforward. The siRNA can be introduced directly into the eye, by injecting it into the vitreous cavity (the jelly-like substance in the center of the eye).

Much remains to be determined, such as how long RNAi will suppress the VEGF gene, how much is required and how often, and whether this treatment is safe and effective against wet age-related macular degeneration. Several new clinical studies designed to resolve these questions are well underway.

Two Promising Drugs For Diabetic Vision Problems

Fri, 14 Dec 2007 06:00:00 CST

Corticosteroids Improve Vision in Diabetics With Macular Edema

Results from a two-year clinical trial at the University of Sydney in Australia further establish the drug triamcinolone acetonide, a corticosteroid, as a promising treatment for people with diabetic macular edema.

Following an injection of the drug into the eye of 4 mg of triamcinolone, 19 eyes (in 34 patients) showed a five-letter improvement on a standard eye chart, compared with only nine eyes treated with a placebo. The average improvement was 5.7 letters. The drug also reduced the thickness of the macula. Benefits of the drug lasted up to two years with repeated treatment.

The standard treatment for macular edema is laser photocoagulation, a procedure that closes the new blood vessels with a laser. But the treatment only improves vision in about 10% of cases. Researchers believe that the drug triamcinolone may block the growth and movement of cells necessary for forming new blood vessels. And the drug may prevent leakage by conserving the tight spaces between cells in the blood vessel walls.

The treatment isn’t without complications, however -- specifically, the development of cataracts and elevation of intraocular pressure, although the researchers say these are manageable with surgery and other drugs. They are conducting an additional clinical trial combining laser treatment with triamcinolone. Results from this study were reported in the journal Ophthalmology (Volume 113, page 1533).

New Drug Stems Blood Vessel Growth in Diabetic Retinopathy

In proliferative diabetic retinopathy -- when new blood vessel growth blocks vision -- the best treatment has been photocoagulation, using lasers to close new blood vessels. Three small studies now suggest that the drug bevacizumab (Avastin), which blocks the activity of a protein that increases blood vessel growth, may be safe and effective.

In the largest study of 45 eyes in 32 patients, the drug reduced blood vessel leakage completely or in part within a week of injection. Leaking had not recurred at an 11-week follow-up in all but one case. One concern: At the largest drug dose, the fellow eye was affected, suggesting the drug was affecting the patient’s entire system, not just the treated eye. Lower doses of the drug did not have that effect.

In a smaller study of three patients, blood vessel growth halted within one to three weeks of injection. And in a study of seven eyes in five patients who had blood vessel growth in the iris after photocoagulation, growth halted after one week of treatment, although two eyes needed a second injection later. These studies were reported in Ophthalmology (Volume 113, page 1695) and in the American Journal of Ophthalmology (Volume 142, page 685).

Is Poor Eyesight Slowing You Down?

Fri, 21 Sep 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Is Poor Eyesight Slowing You Down

Johns Hopkins researchers find that some people with poor vision can compensate for their poor eyesight by creating a mental map of their environment.

Taking a brisk walk is tough to do when you can’t see well. Still, some people with limited vision clip along quite well, and researchers at Johns Hopkins are trying to understand why some with poor vision fare better than others and which of their lessons can be passed along.

The Johns Hopkins studies are part of the Salisbury Eye Evaluation Project (SEE) begun in 1993, when scientists at Johns Hopkins began gathering the vision and health data of roughly 3,000 elderly residents of Salisbury, MD. In the past, research has focused on common problems such as reading, face recognition, and sharpness of vision, measurements that can be taken from seated subjects.

But within the last five to 10 years, technology has improved the ability to measure vision in motion (through virtual environments, portable eye trackers, and faster computers), enabling SEE researchers to concentrate on a relatively new area: the effect that limited peripheral vision has on movement.

What the studies make clear is that vision alone does not determine how well one navigates a trail. In the studies those who were able to walk most quickly and efficiently used both external and internal cues to guide their walks. In other words, they were better able to create a mental map of the environment to augment their sense of where they were.

Lessons to share -- People can learn to compensate for poor peripheral vision by using nonvisual cues such as sounds, muscle responses, and body systems that let them know where they are in space. Those with compromised vision can learn to draw on internal maps of where they are, lessening dependence on visual cues. For instance, when you enter a room through one door, observing a chair on the right and a lamp on the left, and then enter the next time by another door, you can rotate the room in your mind, reorienting yourself to the new entrance.

Visual aids are available as well. In addition to the traditional white cane, there are now sonar devices that provide audible cues about what’s in the immediate environment. Image enhancers like the Low Vision Enhancement System developed by Johns Hopkins and NASA can enlarge images of surroundings. And at key locations like public restrooms in a number of cities in the United States and other countries, Talking Signs are now in use, transmitting voice messages about their location to small handheld boxes.

Perhaps the best news from the SEE studies is that with training and aids, poor vision doesn’t have to mean the end of travel, exercise, or independence.

Johns Hopkins Health Alerts | Vision | Is Poor Eyesight Slowing You Down

Preventing Corneal Abrasions

Fri, 02 Nov 2007 06:00:00 CST

Johns Hopkins Health Alerts | Vision | Corneal Abrasions

Fortunately, most abrasions -- painful as they may be -- leave vision intact. But it’s important to seek medical attention as soon as an abrasion occurs.

Although no one knows just how many corneal abrasions occur, abrasions are among the most common of eye injuries. You may not know exactly how an abrasion happened. But you will feel it. Human beings are equipped to react quickly when the eye is threatened. The epithelium, the outermost of five layers of tissue in the cornea, has thousands of tiny nerve endings that create a hotbed of sensitivity. You’ll probably feel pain, sensitivity to light, and a feeling that something is in your eye. You may also have tearing, blurred vision, a headache, and difficulty keeping your eye open.

If you do have such symptoms of abrasion-- especially pain -- get to an ophthalmologist as soon as possible. But first, if you wear contacts, take them out immediately, with clean hands. You should also wash out your eye with clean water or a saline solution, using a clean eye cup or clean glass. Blinking several times may also help wash out the offending object. Try pulling your upper eyelid over the lower lid: The lashes of the lower lid may brush the particle from the underside of the upper lid. The resulting tears may do this as well. But do not rub your eye or try to remove an object stuck there. This could make the injury worse.

Obviously, the best course is to avoid the abrasion altogether. Here's some advice:

If you’re working with wood, metals, chemicals, or even puttering in the garden or mowing the yard, wear eye protection -- goggles or safety glasses, available at hardware and home supply stores.

Cut down overhanging branches you pass by each day and keep your nails (and those of any babies in the house) well trimmed.

If you wear contact lenses, check with your doctor to make sure they fit well. Wash your hands and lenses before you put in your lenses.

It’s also a good idea to wear sunglasses that shield your eyes from ultraviolet rays, summer and winter.

Johns Hopkins Health Alerts | Vision | Corneal Abrasions

Statins and Cataract Risk

Fri, 31 Aug 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Statins and Cataract Risk

Can certain medications reduce cataract risk? The answer is “yes,” according to researchers at the University of Wisconsin.

Cataracts form painlessly. The most common symptom of a cataract is cloudy or blurry vision. Everything becomes dimmer, as if seen through glasses that need cleaning. Most often, both eyes are affected with cataracts, though vision is usually worse in one eye than in the other. Other symptoms of cataracts include glare, halos, poor night vision, a perception that colors are faded or that objects are yellowish, and the need for brighter light when reading. In some cases, double vision occurs with cataracts.

Another symptom of cataracts is the need for frequent changes in eyeglass and contact lens prescriptions. These symptoms can develop rapidly (in a matter of months) or almost imperceptibly, over many years.

In the early stages of a nuclear cataract, some people may temporarily have an improvement in vision. For example, a person who previously needed reading glasses for presbyopia is able to read without them. This change, which is referred to as second sight, occurs because the cataract alters the shape of the lens, making it better able to focus on nearby objects. Over time, however, this improvement in vision is lost, and progression of the cataract impairs vision.

Recently an article in the Journal of the American Medical Association (Volume 295, page 2752 ) reported that statins, normally used to lower cholesterol, may also lower the risk of nuclear cataracts, the most common type of cataract, occurring in the center of the eye lens.

Some animal studies had earlier suggested that statins might actually increase cataract risk. However, subsequent animal studies and a large British health survey found no risk.

Now, in a five-year follow-up of 1,299 people at risk for developing nuclear cataracts within five years, researchers at the University of Wisconsin, analyzing data from the Beaver Dam Eye Study, found that 12.2% of the statin users had developed nuclear cataracts compared with 17.2% of people who did not use statins. After adjusting for factors like diabetes and smoking, which increase nuclear cataract risk, statin users had a 40% lower the risk of developing nuclear cataracts than nonusers.

The investigators believe it may be the antioxidant effects of the statins that protect eyes. Other studies have shown a link between antioxidants and lowered risk of age-related cataracts. Statins, however, did not lower risk of the other two types of cataracts, cortical (affecting the lens cortex, the layer surrounding the nucleus) and posterior subcapsular (affecting the rear of the lens capsule).

Johns Hopkins Health Alerts | Vision | Statins and Cataract Risk

Research on Age-Related Macular Degeneration

Fri, 12 Oct 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Age-Related Macular Degeneration

Diets High in Simple Carbs May Boost Risk of Age-Related Macular Degeneration

Passing on the fries may do more than manage your waistline: Such restraint may also protect your eyes. In a study at Tufts University reported in the American Journal of Clinical Nutrition (Volume 83, page 880), researchers examined the eyes of 526 women between ages 53 and 73. They also examined 10 years’ worth of data about the women's diets, collected as part of the Nurses Health Study.

Women whose diets had the highest glycemic index, they found, had double the risk of the early form of age-related macular degeneration called age-related maculopathy (ARM) of women who ate low-glycemic index diets. Glycemic index measures how quickly a food makes blood sugar rise. White or refined carbohydrates -- sugar, potatoes, white flour -- have a much higher glycemic index than brown rice, whole-wheat breads and pastas, or legumes like lentils. The amount of carbohydrates that a woman ate, however, made no difference -- suggesting that the quality of carbohydrates, not their quantity, matters most. Still, the researchers are quick to point out that the study does not necessarily mean that simple carbohydrates like sugar cause age-related macular degeneration. It could be that those who pile their plates with fries tend to have an overall health pattern that isn’t healthy -- although researchers adjusted their findings to exclude other high-risk factors for age-related macular degeneration such as cigarette smoking and obesity.

Genetic Factors plus Lifestyle Influence the Risk of Age-Related Macular Degeneration

For some time, researchers have known that age-related macular degeneration has a genetic component. A group of Boston researchers has identified a new gene variant as well as the link between variants in three genes, all of which seem to play a part in causing age-related macular degeneration.

In 2005, scientists found that variations in a gene coding for the protein Complement Factor H (CFH) were common in people with age-related macular degeneration, one of which appeared to account for 43% of the risk for age-related macular degeneration. CFH itself likely protects blood vessels -- including those in the eye -- from inflammation and damage.

Further research identified variants of another gene, BF/C2, that also affect age-related macular degeneration. In the more recent Boston study the researchers have located yet another CFH variant associated with age-related macular degeneration by analyzing samples from more than 2,000 people of European descent over age 60, more than half of whom had either wet or dry age-related macular degeneration.

Another study by members of the same team showed that, among patients in the major AREDS trial (Age-Related Eye Disease Study) these genetic subtypes interact strongly with lifestyle risk factors for age-related macular degeneration such as smoking and body mass index. Overweight smokers with one genetic type had the highest risk of all. Not only may these findings someday help explain age-related macular degeneration, but they might inspire new treatments, too. These findings were reported in the journal Nature Genetics (Volume 38, page).

For more Alerts and Special Reports, please visit the Vision Topic page.

Johns Hopkins Health Alerts | Vision | Age-Related Macular Degeneration

Food for the Eyes

Fri, 20 Jul 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Food for the Eyes

Johns Hopkins doctors discuss the role that nutrients, such as lutein, beta carotene, zinc, and omega-3 fatty acids play in slowing the progression of age-related macular degeneration.

That tempting grilled fish and spinach salad may come with a side of eye protection. In 2006, the National Eye Institute (NEI) began to enroll 4,000 people with varying levels of age-related macular degeneration in a five-year study that will test whether two nutrients in green leafy vegetables and in fish can slow progression of the age-related macular degeneration.

Called AREDS (Age-Related Eye Disease Study) II, the study is somewhat similar to an earlier one, AREDS I, which established that other nutrients -- high-dose oral supplements containing beta carotene, zinc, copper, and vitamins C and E -- decrease age-related macular degeneration progression rates and vision loss.

Here’s a rundown on nutrients that may be serving your sight:

Age-related macular degeneration and lutein and zeaxanthin -- These may sound like exotic European surnames, but they are carotenoids, the antioxidants found in brightly colored fruits and vegetables. Lutein and zeaxanthin (pronounced zee-uh-ZANthin) form the visible yellow pigment of the macula, the small spot at the center of the retina essential for central and detailed vision (such as reading vision).

Scientists believe that lutein and zeaxanthin may protect eyes from age-related macular degeneration. For one thing, they seem to act as a sunscreen, filtering out blue light, a harmful form of sunlight. Lutein and zeaxanthin also do what all antioxidants do: They protect cells from damage by free radicals, imbalanced oxygen molecules that attack healthy cells. And the nutrients may bulk up the macular pigment, also a factor associated with lower risk of age-related macular degeneration.

Macular degeneration and fish oil -- Oily fish like salmon, tuna, and sardines are delicious picnics of omega-3 fatty acids, essential nutrients our bodies can’t manufacture. Some studies suggest an association between one of the acids, DHA (docosahexaenoic acid), and a lower risk of age-related macular degeneration, dry eye (lack of eye moisture), and glaucoma, an eye disease that damages the optic nerve. In fact, the first AREDS revealed that individuals who ingested foods richest in DHA -- the equivalent of two or more servings of fish per week -- had a 40% lower risk of having age-related macular degeneration. Although scientists are not certain how DHA protects the eye, both DHA and its fatty-acid partner eicosapentaenoic acid (EPA) are essential for the development and functioning of the retina, which is packed with DHA, and the brain.

Macular degeneration and beta-carotene, vitamins C and E, zinc, and copper -- This combination of nutrients is the first effective treatment for slowing the progression of age-related macular degeneration. Scientists had suspected that these nutrients might help, based on early small studies. But in 2001, the NEI completed its first seven-year AREDS clinical trial, in a group of subjects that included people at risk for advanced age-related macular degeneration, cataracts, or both. More than 4,000 participants, most of whom had some degree of age-related macular degeneration, took high daily doses of the nutrients. The risk of age-related macular degeneration progression was reduced by 25% for those using the combination supplement who had been considered at greatest risk for progression.

This combination is now sold over-the-counter under the brand names Ocuvite PreserVision and Icaps AREDS Formula, but it is not appropriate for everyone with AMD. If you have AMD, talk to your eye doctor before taking either of these supplements, particularly if you are a smoker or have recently quit smoking. Beta carotene, one of the nutrients in the supplement, may increase the risk of lung cancer in smokers.

For more Alerts and Special Reports, please visit the Vision and Eye Care Topic page.

Johns Hopkins Health Alerts | Vision | Food for the Eyes

Dry Eye Research Update

Fri, 29 Jun 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Dry Eye Research Update

Autologous serum eye drops – promising therapy for dry eye

Autologous serum eye drops, which are derived from a person’s own blood, are gaining ground as a potential treatment for severe dry eye disease that doesn’t respond to conventional treatment. Japanese researchers divided a group of 20 people with severe dry eye disease into two subsets. One group of dry eye patients used only preservative-free artificial tears and the second group of dry eye patients used only autologous serum eye drops for two weeks of treatment. At the end of the treatment period, those who had used the autologous eye drops showed significant improvement of dry eye on several clinical measures of the health of the eye’s surface and reported greater improvement on subjective measures of comfort.

Autologous serum eye drops, contain essential tear components, such as vitamin A and several growth factors. They have been found to be beneficial in treating several eye surface diseases, in addition to dry eye. As for their use in treating dry eye, the researchers say that the next step is to evaluate a larger group of patients over a longer treatment period. This research was reported in the American Journal of Ophthalmology, Volume 139, page. 242.

The connection between dry eye and diabetes

People with diabetes, especially those with poor glycemic control, are more likely than non-diabetic patients to have dry eye, according to an article in the American Journal of Ophthalmology, Volume 139, page 498. Researchers followed the medical records of 159,624 people who belonged to an Israeli HMO for one year. All of the participants were older than age 50, and 22,382 had diabetes. The researchers tracked the use of artificial tears among the patients with diabetes and those who did not have the disorder. At the end of the year, 20.6% of the patients with diabetes and 13.8% of those without diabetes had used artificial tears.

Moreover, the researchers found a clear trend of greater use of artificial tears as glycemic control (measured by levels of HbA1c) declined. The researchers note that dry eye in people with diabetes may be due in part to damage to the microvasculature of the lacrimal gland (which secretes tears) in the eye. Sensory neuropathy (a nerve disorder) in the cornea also may play a role, as may side effects of medications used to control diabetes.

Johns Hopkins Health Alerts | Vision | Dry Eye Research Update

Remedies for Red Eye

Fri, 18 May 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Remedies for Red Eye

Do your eyes turn red and itchy every spring and summer? It could be allergic conjunctivitis – a treatable, but uncomfortable allergy condition.

Allergic conjunctivitis is a common cause of red, itchy eyes. Although allergies are best known for causing nasal symptoms, they also can be irritating to the eyes. In allergic conjunctivitis, the affected part of the eye is the conjunctiva, the thin, elastic tissue that covers the white of the eye and lines the inside of the eyelid. Fortunately, doctors and patients have an array of therapies at their disposal to prevent or treat allergic conjunctivitis.

Conjunctivitis can be caused by either allergies or infection. In allergic conjunctivitis, the eyes become red and itchy, with a watery, stringy, or ropelike discharge. Both eyes are usually affected. In addition, people with allergic conjunctivitis often have a history of allergic rhinitis, asthma, or eczema. Infectious conjunctivitis also leads to eye redness but is more likely to produce tearing and discharge in one or both eyes. People with these symptoms may need antibiotics and should see a doctor.

Allergic conjunctivitis can be seasonal (occurring only at specific times of the year) or perennial (occurring year-round). Seasonal allergic conjunctivitis is typically caused by outdoor allergens, such as pollen, and the perennial form is usually caused by indoor allergens, such as cockroaches, dust mites, or pet dander. Skin or blood testing by an allergist can pinpoint a patient’s specific triggers.

Treatments for allergic conjunctivitis -- To prevent symptoms of allergic conjunctivitis, patients should learn to avoid or limit their exposure to triggering substances. When symptoms do erupt, cold compresses on the eyes may help relieve conjunctivitis symptoms in the short term.

Medications are a mainstay of treatment for allergic conjunctivitis. Some doctors recommend using artificial tears, which provide a barrier between allergens and the eye; they also help dilute and flush out the allergens that contact the eye. Other conjunctivitis medications include:

Antihistamine eyedrops -- for acute treatment of redness and itching

Oral antihistamine medication -- to reduce itching

Vasoconstrictors -- for short-term treatment of redness and swelling

Nonsteroidal anti-inflammatory eyedrops -- for reducing symptoms in some patients

Mast-cell inhibitors -- to treat a range of symptoms, including itching, swelling, and watery eyes

Doctors usually prescribe corticosteroid eyedrops only for severe cases of allergic conjunctivitis and only for short periods because of the risk of side effects, including cataract and elevated eye pressure, which may lead to glaucoma. For some conjunctivitis patients, allergy shots may be a useful way to prevent allergies from recurring.

For more Alerts and Special Reports, please visit the Vision Topic page.

Johns Hopkins Health Alerts | Vision | Remedies for Red Eye

Are You at Risk for Diabetic Retinopathy?

Fri, 08 Jun 2007 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Are You at Risk for Diabetic Retinopathy

Diabetic retinopathy usually has no symptoms, so if you have diabetes it’s important to follow these five steps to reduce your risk of developing retinopathy.

Diabetic retinopathy, a potential long-term complication of diabetes, is an eye disorder caused by damage to blood vessels in the retina, the light-sensitive tissue at the back of the eye. Mild forms of the disorder are common: Almost all people with type 1 diabetes and more than 70% of people with type 2 diabetes will experience some degree of retinopathy. Without treatment, diabetic retinopathy can progress from mild, nonproliferative retinopathy to more serious proliferative retinopathy, which can lead to blindness.

What can you do? People with diabetes can take these steps to help reduce their risk of developing retinopathy or having their retinopathy progress.

Retinopathy Tip 1: Have Regular Eye Exams. Regular visits to an ophthalmologist are essential to detect early retinal damage so it can be monitored and, if necessary, treated with laser therapy. An annual eye exam is recommended for people who have had type 1 diabetes for more than five years. Everyone with type 2 diabetes should have an eye exam as soon as diabetes is diagnosed, and annually thereafter.

Retinopathy Tip 2: Control Blood Glucose. The most important way to prevent diabetic retinopathy is to keep blood glucose levels as close to normal as possible. This is because high blood glucose levels can damage blood vessels in the retina. The best way to achieve tight glucose control and reduce your risk of developing diabetic retinopathy is to measure your blood glucose levels frequently with a glucose monitor and to follow the advice of a doctor who manages diabetes aggressively. It is also important to have a hemoglobin A1c (HbA1c) test every three to six months to evaluate your blood glucose control. Experts recommend that people with diabetes maintain an HbA1c level below 7%. Studies have found that every 10% reduction in elevated HbA1c levels is associated with a 39% reduction in the risk of diabetic retinopathy.

Retinopathy Tip 3: Control Blood Pressure. High blood pressure can also damage blood vessels in the retina and cause retinopathy. Research shows that keeping blood pressure as close to normal as possible can help prevent the onset and progression of retinal damage. Experts recommend that people with diabetes keep their blood pressure at or below 130/80 mm Hg to prevent long-term complications.

Retinopathy Tip 4: Control Cholesterol Levels. Studies have reached conflicting conclusions as to whether high blood cholesterol is associated with the development or progression of diabetic retinopathy. However, lowering blood cholesterol levels is already a priority for people with diabetes because of their increased risk of heart attack and stroke, and preserving vision may be an added benefit of taking steps to lower cholesterol.

Retinopathy Tip 5: Stop Smoking. Some -- but not all -- studies find that smoking cigarettes is a risk factor for diabetic retinopathy. Even if there is no direct link, the blood pressure-raising effect of smoking can increase the risk of retinopathy.

Recognize the Warning Signs of Retinopathy: Diabetic retinopathy usually has no symptoms. However, any of the following visual changes could indicate retinal damage, and you should contact your eye doctor immediately if you experience any of them:

sudden loss of vision in one eye

blurred vision

problems reading

double vision

pain in one or both eyes

pressure in your eyes

the appearance of spots or floaters

problems seeing things with your peripheral vision

Johns Hopkins Health Alerts | Vision | Are You at Risk for Diabetic Retinopathy

Neuroprotection -- New Frontier in the Treatment of Glaucoma

Fri, 06 Apr 2007 06:00:00 CDT

UPDATE

As part of our ongoing effort to ensure that this website is up to date, we have determined that the information in the article Neuroprotection -- New Frontier in the Treatment of Glaucoma is no longer current, and has therefore been removed.

If you would like to read related articles about vision, please go to the Vision and Eye Care Topic page. Thank you.

Primer on Cataracts

Fri, 16 Mar 2007 06:00:00 CST

Johns Hopkins Health Alerts | Vision | Causes and Symptoms of Cataracts

While there’s currently no effective drug therapy to prevent cataracts from forming, cigarette smoking, certain drugs, eye injuries, sunlight, diabetes, and even obesity can increase your risk.

If you’re in your forties or fifties, you probably know someone who has cataracts. That’s because while cataracts can occur at any age (in fact, babies can be born with them), they are most common later in life. About 75% of people in the United States over age 60 have some signs of cataracts. An estimated 20.5 million Americans over age 40 (approximately 17%) had a cataract. That number is expected to reach 30.1 million by 2020. Cataract surgery is the most commonly performed surgical procedure in the United States. More than 1.5 million cataract operations are performed each year.

A cataract is an opacification (cloudiness) of the eye’s normally clear crystalline lens. Derived from the Latin word meaning “waterfall,” the term cataract arose from the ancient misconception that cataract symptoms were caused by evil liquids that mysteriously flowed into the eye.

The cause of most cataracts is unknown, but at least two factors associated with aging contribute to cataract development:

First, clumping of proteins in the lens leads to scattering of light and a decrease in the transparency of the lens.

Second, the breakdown of lens proteins leads to the accumulation of a yellow-brown pigment that clouds the lens.

Researchers have found certain chemical changes in the eyes of people with cataracts. These changes include a reduced uptake of oxygen by the lens and a rise in the water content of the lens, which is later followed by dehydration. When cataracts form, levels of calcium and sodium in the lens increase, and levels of potassium, vitamin C, and protein decrease. In addition, lenses with cataracts appear to be deficient in the antioxidant glutathione. However, studies on the use of medications or vitamins to alter the levels of these substances in the lens have not produced promising results. Currently, there is no effective drug therapy to prevent cataracts from forming. But cigarette smoking, certain drugs, eye injuries, sunlight, diabetes, and even obesity can increase the risk of cataracts.

Cataracts form painlessly. The most common symptom is cloudy or blurry vision. Everything becomes dimmer, as if seen through glasses that need cleaning. Most often, both eyes are affected, though vision is usually worse in one eye than in the other. Other symptoms include glare, halos, poor night vision, a perception that colors are faded or that objects are yellowish, and the need for brighter light when reading.

In some cases, double vision occurs. This is caused by the passage of light through a lens that has irregular areas of opacity, which can split the rays of light from a single object and focus them on different parts of the retina. Another symptom of cataracts is the need for frequent changes in eyeglass and contact lens prescriptions. These symptoms can develop rapidly (in a matter of months) or almost imperceptibly, over many years.

Johns Hopkins Health Alerts | Vision | Causes and Symptoms of Cataracts

Exercise and Glaucoma: Staying fit benefits your eyes

Fri, 23 Feb 2007 06:00:00 CST

Johns Hopkins Health Alerts | Vision | Glaucoma Exercise

Simply going for a walk three or more times a week may be all you need to protect against glaucoma progression.

If you’ve just been diagnosed with glaucoma, you undoubtedly want to do everything you can to be as healthy as possible for as long as possible. As part of that, you may wonder whether changes in your overall lifestyle, including changes in the amount or type of exercise you get, may help control the disease.

While the mainstay of glaucoma therapy remains lowering intraocular pressure (IOP) with medication, laser treatment, or surgery, some evidence does suggest that a regular exercise program can help support your medical therapy. But what kind of exercise is best? Is there anything in particular you should -- or shouldn’t -- do? Here’s an overview of what’s known.

Overall, exercise has been found to lower IOP. Studies also have found that it improves blood flow to the retina and optic nerve. In one study, jogging for 20 minutes lowered IOP by 1 mm Hg to 8 mm Hg. In another, weight lifting also led to decreases in IOP, with IOP dropping by 14.5% after the third set of chest presses and 13.2% after the third set of leg presses. While the jogging and weight training studies were conducted in healthy, athletic people without glaucoma, exercise has also been found to benefit sedentary people with ocular hypertension. For instance, three months of moderate exercise for nine sedentary people suspected of having glaucoma decreased mean IOP by 4.6 mm Hg (20% for these particular patients).

If you aren’t already active, there’s no need to adopt a hard-core exercise program. Simply going for a walk three or more times a week can protect against glaucoma progression. The catch? The exercise benefit continues only as long as you continue exercising. In the study of the sedentary glaucoma suspects, just three weeks of deconditioning undid the beneficial effects.

Caveats to consider. It’s important to avoid the Valsalva effect (the technical term for what happens when, after an inhalation, you hold your breath and apply pressure against your epiglottis), as this appears to have a negative impact on IOP. Thus, if you’re interested in weight lifting or other forms of resistance exercise, be sure to get proper training on breathing techniques. The same holds true for yoga and Pilates, as people sometimes incorrectly hold their breath either going into or coming out of a pose.

Another concern regarding yoga: It’s best to avoid all inverted poses if you have glaucoma. This includes headstand, shoulderstand, and the plow. While few studies have been conducted on yoga and glaucoma, there is some evidence that inverted poses increase IOP, so be sure to discuss alternative poses or modifications with your yoga instructor.

Bottom line on glaucoma and exercise. A regular program of moderate exercise will have multiple benefits for your overall health. While its long-term impact on your glaucoma progression is unknown, it is likely to support your current treatment program. If you have any questions about your existing exercise program, or any concerns about starting a new activity, check with your ophthalmologist.

For more Alerts and Special Reports, please visit the Vision and Eye Care Topic page.

Johns Hopkins Health Alerts | Vision | Glaucoma Exercise

Macular Degeneration Drug Update

Fri, 02 Feb 2007 06:00:00 CST

Johns Hopkins Health Alerts | Vision | Macular Degeneration Drug Update

Dr. Susan Bressler talks about two new medications for age-related macular degeneration – Avastin and Lucentis.

Q. I’ve heard that new medications to treat wet age-related macular degeneration (AMD) are available. Are these new medications better than current treatments?

A. Two new medications—Avastin (bevacizumab) and Lucentis (ranibizumab) -- are now in use to treat macular degeneration. These new macular degeneration treatments are exciting because they offer the opportunity to slow vision loss and may restore vision, to a degree, in some people with wet macular degeneration. Older drugs for wet macular degeneration, like Macugen (pegaptanib), also offer the possibility of decreasing further vision loss but rarely lead to the restoration of vision.

Both new wet macular degeneration medications inhibit angiogenesis—the process by which the body creates new blood vessels. Wet macular degeneration is caused by the abnormal growth of blood vessels below the retina. These fragile vessels often burst, and blood, fluid, and the vessels themselves cause damage to the eye.

Avastin was approved by the FDA in 2004 for intravenous administration to treat colon cancer, but many ophthalmologists found that very small doses of it injected into the eye appeared effective against wet macular degeneration. Genentech, the company that produces Avastin, tested and reformulated the drug as a specific treatment for wet macular degeneration. The result is Lucentis, which was FDA approved for wet macular degeneration in 2006.

Genentech claims the newer macular degeneration drug can more easily pass through the retina, but perhaps the biggest difference between the two Genentech drugs is their cost—a dose of Avastin for wet macular degeneration costs from $30–$200, while treatment with Lucentis can cost thousands of dollars. Medicare covers Lucentis, but it still may cost more than Avastin depending on your particular prescription plan.

Neither macular degeneration medication has a very long track record, so which one is the best choice? According to ophthalmologist Susan Bressler, MD., the Julia G. Levy, Ph.D., Professor of Ophthalmology at Johns Hopkins University School of Medicine, "The advantage of Lucentis is that its safety and efficacy in people with wet macular degeneration have been more firmly established than those of Avastin.” However, Dr. Bressler adds, “I would recommend Avastin for many individuals who have wet macular degeneration and cannot afford to receive Lucentis.” The National Institutes of Health is sponsoring a study that will compare the safety and effectiveness of the two drugs in AMD patients.

According to Dr. Bressler, "Among the available treatment options, these two medications offer the greatest chance of stabilization or recovery of vision for wet macular degeneration patients.”

Johns Hopkins Health Alerts | Vision | Macular Degeneration Drug Update

Herbs and Your Eyes

Fri, 15 Dec 2006 06:00:00 CST

Johns Hopkins Health Alerts | Vision | Herbs and Your Eyes

8 herbs and supplements that could mean trouble for your eyes

Are you taking herbs or nutritional supplements for your health? If so, it’s important to be aware of the potential for side effects. A study that included case reports submitted to the National Registry of Drug-Induced Ocular Side Effects highlighted several adverse ocular effects linked to the use of certain herbs and nutritional supplements.

The side effects of the herbs and supplements ranged from eye dryness to retinal hemorrhages and temporary loss of vision. In most cases, side effects were associated with higher doses of the particular herbs or supplement, and they cleared up once the person stopped taking the herbs and supplements in question. The study linked the following eight herbs and supplements to clinically significant ocular side effects:

Canthaxanthin. This carotenoid is found naturally in certain foods, particularly shellfish and chanterelle mushrooms. It’s used as a coloring to add an orange-red hue to foods, cosmetics, and animal feed.

Chamomile (Matricaria recutita, Camomilla recutita). Chamomile is often used to treat insomnia, indigestion, and skin problems.

Datura (Datura stramonium and D. wrightii). This supplement is sometimes used to treat asthma, bronchitis, and coughs.

Echinacea (Echinacea purpurea). This top-selling herb is used primarily to treat upper respiratory infections.

Ginkgo (Ginkgo biloba). This supplement is extremely popular, used to boost memory and to treat a number of conditions, including asthma, tinnitus, vertigo, and varicose veins.

Licorice (Glycyrrhiza glabra). Licorice is often used to treat a variety of conditions, including respiratory tract infections and constipation.

Niacin. In tablet form, niacin is used to treat cardiovascular disease. It also can be found naturally in certain foods, including red meat, nuts, and grain.

Vitamin A. This vitamin is so important to health that you’d be hard-pressed to find a daily vitamin supplement without it. The daily recommended intake of vitamin A is 700 IU for women and 900 IU for men.

With some of these herbs, there are data on interactions with other medications or cautions about discontinuing them before surgery. For instance, the herb ginkgo interacts with haloperidol (Haldol), and it can increase the side effects of antidepressants and certain antibiotics. And because it’s a blood thinner, you have a greater risk of bleeding when you take it with other anticlotting drugs, such as aspirin or warfarin (Coumadin). Ginkgo also increases the risk of bleeding during surgery. In the case of licorice, do not take it if you are taking a diuretic, digoxin (Lanoxicaps, Lanoxin) , or insulin.

If you are facing eye surgery (or any other type of surgery), be sure to tell your physician which herbs or supplements you are taking. While the recommended time for discontinuing herbs or supplements before surgery varies, the typical recommendation is two weeks. That should allow enough time for the herbs or supplements to clear your body, thus decreasing the likelihood of any drug interactions or other side effects, including problems with anesthesia. The bottom line: Any product that has a therapeutic effect can also have a side effect. Herbs and supplements are no exception.

Johns Hopkins Health Alerts | Vision | Herbs and Your Eyes

Seeing Double? See a Doctor

Fri, 12 Jan 2007 06:00:00 CST

Johns Hopkins Health Alerts | Vision | The Causes and Symptoms of Double Vision

Johns Hopkins Professor Susan B. Bressler, M.D. discusses the causes and treatment options of double vision.

Double vision, or diplopia, is not the same as blurry vision. People who have double vision see two distinct clear images of a single object, rather than one blurred image. Seeing double can interfere with even the simplest of activities and make complicated tasks impossible. There are many reasons you might have double vision and treatments are readily available once the cause is identified. Because an underlying health problem may be to blame, it is very important to seek medical help.

Binocular double vision -- There are two types of double vision -- binocular and monocular. Binocular double vision is present only when both eyes are open. The double vision disappears if either eye is closed. Binocular double vision is caused by problems with the extraocular muscles that control the eyeball or the nerves that signal these muscles. If the eyeballs aren’t correctly aligned and moving in synchrony with one another, the images generated from each eye are focused on a different point and don’t match up. Double vision is the natural result.

According to Susan B. Bressler, M.D., Professor of Medicine in the Department of Ophthalmology at Johns Hopkins, the two most common causes of binocular double vision in people over 50 are thyroid conditions, such as Graves’ disease, and cranial nerve damage. Graves’ disease can affect the extraocular muscles directly. In most cases, however, underlying nerve damage causes the extraocular muscles to malfunction. Multiple sclerosis, a brain tumor, head trauma, or stroke can all damage the cranial nerves, but the most common cause is diminished blood flow due to high blood pressure or diabetes.

Giant cell arteritis, an inflammation of the arteries that often affects blood vessels in the head, can also cause double vision. If you suspect that you have giant cell arteritis (other symptoms are fever, weakness, weight loss, headaches, temple pain, and stiffness of the neck, hips, and shoulders) you should promptly contact your physician. Immediate treatment with corticosteroids is typically recommended to avoid blindness and other serious complications.

Monocular double vision -- Monocular double vision is present with both eyes open but, unlike binocular double vision, persists when the problematic eye is open and the contralateral (fellow) eye is closed. Monocular double vision is caused not by misalignment, but rather by problems in the eyeball itself. Astigmatism, dry eye, and some retinal problems or certain cataracts can all cause monocular double vision.

Getting Treatment for Double Vision

Some cases of double vision resolve after a change of eyewear prescription. Binocular double vision may be treated with prisms incorporated into glasses or with an eye patch. If the condition doesn’t improve or resolve using these measures, surgery may be considered. Monocular double vision is addressed by treating the underlying condition, using anything from eyedrops (for dry eyes) to surgery (for cataracts).

A word of warning: Over time, binocular double vision may seem to go away on its own, as the brain eventually learns to suppress one of the mismatching images to avoid seeing double. While the symptom of double vision improves, you may still be suffering from whatever condition caused the double vision in the first place. If you’re experiencing double vision, make an appointment with an ophthalmologist as soon as possible. With so many possible causes, the sooner you seek help, the better your chances of seeing clearly in the future.

Johns Hopkins Health Alerts | Vision | The Causes and Symptoms of Double Vision

Diagnosing Cataract Disease

Tue, 17 Oct 2006 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Symptoms of Cataracts

Is your vision blurry, especially at night or in very bright light? It could be an early symptom of cataracts.

A cataract is a clouding of the lens of the eye that interferes with clear vision. Unlike a healthy, transparent lens, which focuses light rays precisely onto the retina, a lens clouded by a cataract loses its ability to focus light rays. The light that reaches the retina is scattered and diffuse, causing blurry vision. The amount of vision impairment depends on the size and density of the cataract and where it is located in the lens: the nucleus, cortex, or posterior lens capsule. A cataract in the periphery of the cortex, for example, has little effect on vision because it does not impede the passage of light through the center of the lens. On the other hand, a dense nuclear cataract causes severe blurring, interfering primarily with distant vision (at first). A cataract that develops in the posterior capsule has a greater effect on near vision and also causes sensitivity to glare.

Cataracts form painlessly. The most common symptom of a cataract is cloudy or blurry vision. Everything becomes dimmer, as if seen through glasses that need cleaning. Most often, both eyes are affected, though vision is usually worse in one eye than in the other. Other cataract symptoms include glare, halos, poor night vision, a perception that colors are faded or that objects are yellowish, and the need for brighter light when reading. In some cases, double vision occurs. This is caused by the passage of light through a lens that has irregular areas of opacity, which can split the rays of light from a single object and focus them on different parts of the retina.

Another symptom of cataracts is the need for frequent changes in eyeglass and contact lens prescriptions. These cataract symptoms can develop rapidly (in a matter of months) or almost imperceptibly, over many years. In the early stages of a nuclear cataract, some people may temporarily have an improvement in vision. For example, a person who previously needed reading glasses for presbyopia is able to read without them. This change, which is referred to as second sight, occurs because the cataract alters the shape of the lens, making it better able to focus on nearby objects. Over time, however, this improvement in vision is lost, and progression of the cataract impairs vision.

Individuals with cortical or posterior subcapsular cataracts often have worse vision in bright light; for example, they may have problems with night driving because of the brightness of oncoming headlights. Bright light causes the pupils to contract and restricts the passage of light to the center of the lens (the part that may be most severely affected by the cataract).

Johns Hopkins Health Alerts | Vision | Symptoms of Cataracts

Coping With Prescription Drug Costs

Thu, 16 Nov 2006 06:00:00 CST

UPDATE

As part of our ongoing effort to ensure that this website is up to date, we have determined that the information in the article Coping With Prescription Drug Costs is no longer current, and has therefore been removed.

If you would like to read related articles about vision and eye care, please go to the Vision Topic page. Thank you.

Promising Drug for Age-Related Macular Degeneration

Wed, 16 Aug 2006 14:32:38 CDT

UPDATE

As part of our ongoing effort to ensure that this website is up to date, we have determined that the information in the article Promising Drug for Age-Related Macular Degeneration is no longer current, and has therefore been removed.

If you would like to read related articles about vision, please go to the Vision and Eye Care Topic page. Thank you.

Could Medication Be Causing Your Vision Problems?

Tue, 12 Sep 2006 06:00:00 CDT

Johns Hopkins Health Alerts | Vision | Vision Problems and Drug Side Effects

Many popular drugs can cause side effects, such as blurred vision, light sensitivity, or excessive tearing. Here are seven common culprits.

Vision problems can be an unwanted side effect of many different medications. Most of these drugs will cause only temporary visual disturbances -- such as blurred or double vision, dry eyes, excessive tearing, puffy eyelids, sensitivity to light, seeing a yellow or blue tinge, or a change in eye color -- that disappear with time or once the medication is discontinued. However, long-term use of some medications may result in more serious vision disorders.

Always consider drug side effects when visual symptoms develop, and be sure to tell your ophthalmologist or optometrist about all medications you are taking. Regular use of any drug associated with serious vision disorders merits periodic monitoring of the eyes. Listed below are some of the most common drugs associated with vision problems.

Antiarrhythmia drugs, such as amiodarone (Cordarone) and digoxin (Lanoxin), are used to treat abnormal heart rhythms and may cause visual disturbances such as blurred vision, yellow vision, or blue-green halos around objects.

Antimalarial drugs, such as chloroquine (Aralen) and hydroxychloroquine (Plaquenil), are used not only for malaria, but also for rheumatoid arthritis and lupus. They may cause visual disturbances such as blurred vision, and prolonged therapy may lead to irreversible retinopathy.

Corticosteroids, such as prednisone may lead to glaucoma or cataracts. Oral treatments (commonly used for arthritis) are linked to cataracts, while the inhaled versions used to treat asthma are associated with both cataracts and glaucoma.

Erectile dysfunction drugs, like sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra), can temporarily cause objects to have a blue tinge to them, blurred vision, and sensitivity to light.

Phenothiazines, like chlorpromazine and thioridazine, are used to treat schizophrenia and other conditions. These drugs may lead to blurred vision, changes in color vision, and difficulty seeing at night.

Tamoxifen, which is used to reduce the risk of breast cancer recurrences, may lead to blurred vision, changes to the retina and cornea, and cataracts.

Tamsulosin (Flomax), an alpha blocker commonly prescribed for the treatment of benign prostatic hyperplasia, has been associated with intraoperative floppy iris syndrome (IFIS). In the condition, the pupil can suddenly constrict during surgery, leading to potentially serious complications during the operation. However, if your surgeon knows before surgery that you're taking tamsulosin, he or she can alter the sugical technique to avoid IFIS.

Johns Hopkins Health Alerts | Vision | Vision Problems and Drug Side Effects

Catching Diabetic Retinopathy in Time

Tue, 18 Jul 2006 09:25:07 CDT

Johns Hopkins Health Alerts | Vision | Early Treatment of Diabetic Retinopathy

Because significant retinopathy may be present at the time of diagnosis in people with type 2 diabetes, an eye examination by an ophthalmologist is advised at that time and annually thereafter.

Researchers estimate that more than 40% of middle-aged and older Americans with diabetes have the potentially vision-threatening eye complication retinopathy—damage to small blood vessels in the eye due to high blood glucose levels.

A review of eight diabetic retinopathy studies, a federal health survey, and Census data suggests that retinopathy affects more than four million U.S. adults age 40 and is the most common eye complication of diabetes.

Early treatment of even advanced retinopathy can usually halt vision loss. But diabetic retinopathy often causes no symptoms—so periodic eye exams are necessary to detect retinopathy. Even proliferative retinopathy (the most dangerous form of the disease) does not produce symptoms initially. Symptoms of proliferative retinopathy develop only when there is bleeding—the patient sees spots or showers of small spots called floaters, which can be severe enough to block vision entirely. Sudden bleeding into the vitreous humor can also cause rapid vision loss. Blurring of vision can occur if blood vessel changes cause closure of the small vessels supplying the macula (a small sensitive area at the center of the retina) or macular edema (swelling of the macula caused by leakage and accumulation of fluid).

People with type 1 diabetes should begin seeing an ophthalmologist for annual eye exams no later than five years after diabetes is diagnosed. Because significant retinopathy may be present at the time of diagnosis in people with type 2 diabetes, an eye examination by an ophthalmologist is advised at that time and annually thereafter. More frequent exams are needed for people with more advanced retinopathy.

Johns Hopkins Health Alerts | Vision | Early Treatment of Diabetic Retinopathy

How To Live Better With Low Vision

Thu, 15 Jun 2006 09:21:13 CDT

Johns Hopkins Health Alerts | Vision | Tips for Vision Impaired Patients

7 practical strategies to help visually impaired patients maintain their independence

Mild vision impairment has little effect on day-to-day activities, but moderate to severe impairment from a condition such as glaucoma or age-related macular degeneration can make it difficult for people to perform common household tasks. Ophthalmologists and low-vision counselors recommend these simple, practical strategies to help patients with low vision maintain their independence.

Always leave doors completely open or completely closed. This reduces the risk of accidentally walking into the door edge if you have low vision.

Tack down loose rugs—and use nonslip mats beneath them. Or use furniture to hold rugs down to prevent slipping and tripping.

Tape a colorful piece of paper to all clear glass doors. If you have low vision, this will help you determine whether the door is open or closed and prevent collisions.

Avoid using glass-topped coffee or end tables. The edges are extremely difficult to see, making bumping injuries more likely if you have low vision.

Mark the important settings on the dials of the stove, washer, dryer, and other appliances using brightly colored tape.

Mark the outer edge of all indoor and outdoor stairs. Use a strip of paint or non-skid material in a color that contrasts with the rest of the step. The strip should extend about 2 inches from the edge—both horizontally and vertically—and should go across the full width of the step. This reduces the chances of tripping or falling on the stairs if you have low vision.

Have someone help you arrange clothing if you have color-vision problems. Separate items according to color and then use labeled dividers to identify them.

Johns Hopkins Health Alerts | Vision | Tips for Vision Impaired Patients

How To Prevent Age-Related Macular Degeneration (AMD)

Sun, 16 Apr 2006 13:48:58 CDT

Johns Hopkins Health Alerts | Vision | Slowing Age-Related Macular Degeneration

Steps to prevent age-related macular degeneration or slow its progression include dietary supplements, diet, and, possibly, reduced exposure to sunlight.

Age-related macular degeneration (AMD) affects the macula, the central, most sensitive part of the retina. In the United States, age-related macular degeneration is the leading cause of severe and irreversible loss of central vision in people over age 40, affecting 1.7 million Americans, or 1.47% of people in this age group. Most people in this group have non-neovascular macular degeneration, which often does not seriously impair vision. But neovascular macular degeneration, a more severe form of the disorder, can cause vision loss.

Some studies indicate that people can take steps to prevent age-related macular degeneration or slow its progression. Steps to prevent or slow age-related macular degeneration include dietary supplements, diet, and, possibly, reduced exposure to sunlight.

The effect of dietary supplements on the risk and progression of age-related macular degeneration was investigated in the Age-Related Eye Disease Study, which included more than 3,500 people (age 55 to 80). For an average of six years, participants took dietary supplements (containing antioxidants, zinc, or antioxidants plus zinc) or a placebo. None of the dietary supplements reduced the risk of developing age-related macular degeneration. But in those with intermediate or advanced age-related macular degeneration, the supplement containing antioxidants plus zinc reduced the risk of more advanced age-related macular degeneration by 25%.

The antioxidant plus zinc supplement used in the study contained 500 mg of vitamin C, 400 IU of vitamin E, 15 mg of beta-carotene, 80 mg of zinc oxide, and 2 mg of cupric oxide. It is sold under the brand name Ocuvite PreserVision and is available without a prescription. (Smokers and people who have recently quit smoking should not use this supplement, because the beta-carotene in it has been found to increase the risk of lung cancer in smokers.)

Other studies have suggested that eating fruits and vegetables high in carotenoids, especially those high in beta-carotene (carrots, spinach, and cantaloupes, for example), might help prevent age-related macular degeneration.

In addition, avoiding excessive exposure to sunlight has been found to be protective in some studies. In the Beaver Dam Eye Study, people who spent at least five hours a day in the summer engaged in leisure activities outdoors in their teens and 30s had twice the rate of age-related macular degeneration as those who spent fewer than two hours outside each day. In addition, people who wore hats and sunglasses tended to have a lower rate of age-related macular degeneration.

Johns Hopkins Health Alerts | Vision | Slowing Age-Related Macular Degeneration

Statin Drugs Protect Against Glaucoma

Thu, 20 Apr 2006 13:45:54 CDT

Johns Hopkins Health Alerts | Vision | Statins to Protect Against Glaucoma

Patients who had used statins for two years or longer were 40% less likely to develop glaucoma than those who had used the drugs for less time.

The long-term use of cholesterol-lowering drugs called statins (such as Zocor, Lipitor, and Crestor) appears to reduce the risk of glaucoma among men, particularly those with cardiovascular disease and high cholesterol, according to recent research published in the Archives of Ophthalmology.

Statins have previously been linked to possible decreased risk of age-related macular degeneration, and there are sound scientific reasons why these drugs may also protect against glaucoma.

Researchers evaluated the medical records of 667 men age 50 or older who had recently developed glaucoma, then determined their statin use. For comparison, statin use was also recorded for 6,667 control subjects without glaucoma.

Patients who had used statins for two years or longer were 40% less likely to develop glaucoma than those who had used the drugs for less time. The benefits were most pronounced for men with cardiovascular disease and high cholesterol. A protective effect against glaucoma was also observed for non-statin anti-cholesterol drugs.

The researchers hypothesize that statins might reduce the risk of glaucoma directly, by reducing atherosclerosis in the optic nerve, or indirectly, by improving blood flow in the eye. Statins might also enhance the ability of cells in the trabecular meshwork (a spongy network of connective tissue located just in front of the iris) to drain excess fluid.

Johns Hopkins Health Alerts | Vision | Statins to Protect Against Glaucoma