By Richard P. Holm, MD
The first hint that I had glaucoma, came when I was at the eye doctor and it was discovered by machine testing that I had lost vision in the peripheral areas around but not including the center point of vision on my left eye. Loss of peripheral vision is a sign that glaucoma might be occurring, and indeed, when they measured the pressure within my eyes, it was increased on the left. I had no idea something was wrong.
An estimated three million people in the U.S. have glaucoma, one-half have no idea something is wrong, and 120,000 are blind as a result. Glaucoma is the second leading cause of blindness in the world, especially for those coming from African origins. Once discovered, we have treatment, so the best preventive move is to get routine glaucoma testing.
Glaucoma causes peripheral vision loss and preserves central vision until late in the disease. Central vision is that concentrated view we have of the object at which we are staring. It is the eye of the needle into which we are trying to put the thread; the subtle smile of the mysterious woman about which we are painting; the target into which we are aiming our arrow. Say it again, early on, central vision is preserved in glaucoma.
Remember, glaucoma causes progressive loss of peripheral vision. Peripheral vision is important, allowing us to see the shooting star that flashes suddenly from the eastern horizon, while we stare at the big dipper and the northern star; to see the ball and boy that might jet out from behind that car, while we drive down the road; to see the guy across the room who has captured our attention, while we secretly watch him with peripheral vision.
For comparison, macular degeneration, causes the opposite kind of loss to that of glaucoma, specifically, loss of central vision while preserving peripheral vision. Both conditions affect the retina, that blanket of nerves covering the back side of the eye, which, like a camera, captures the image of an autumn moon rising on a South Dakota lake, a wind wave of grass moving on a prairie hill, or the surprised face of discovery on a visiting grandchild.
Take home message: people don’t realize there is peripheral vision loss resulting from glaucoma, until the damage has been done. Get in to have routine eye testing. You may have no idea something is wrong.