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)
