Fox News pundit Glenn Beck's announcement that he is losing his vision shed light on an eye condition rarely discussed. Macular dystrophy, not to be confused with its more common cousin macular degeneration, is a genetic disorder that can cause legal blindness.
We spoke with Dr. Blaine Cribbs, an ophthalmologist and retina specialist with Emory Eye Center, and optometrist Dr. Tom Spetalnick, clinical director of the Woolfson Eye Institute in Atlanta, about the condition and what it means for eye health.
What is macular dystrophy?
Dr. Spetalnick: Macular dystrophy is a general term that includes a lot of different conditions that have different levels of aggressiveness. Essentially the short answer is it's any of a group of disorders that are inherited and progressive.
Dr. Cribbs: Without knowing exactly what his diagnosis is, it is impossible to guess what is going on with Mr. Beck, but the most common form of macular dystrophy is vitelliform, which can present early onset in children or as adults.
How does it differ from macular degeneration?
TS: Macular degeneration is something not necessarily inherited. Macular dystrophy is more likely to be traceable to a gene or an inherited pattern. When young patients [have] macular problems, it’s more likely to be a dystrophy, as opposed to macular degeneration, which is an age–related loss of function and change of anatomy.
How does macular dystrophy affect one’s vision?
TS: It can vary. Some people will have minor loss of vision that is minimally progressive and others will have complete loss of the central vision. The retina is the seeing part of the eye and the macula is the central part of that, which is responsible for the greatest detail vision. When you need to see detail, you point your macula at that, so people with a type of dystrophy will have some loss of whatever they are looking at directly. Macular dystrophy could certainly cause legal blindness, which means you can’t see any better than 20/200 out of both eyes.
BC: Macular dystrophy won't take away night vision or peripheral vision, but it can cause severe impairment or blind spots.
What are early warning signs?
BC: The first things people notice are small blind spots or maybe a distortion of the vision when they are trying to read; the lines or letters would be crooked or missing.
TS: It could present harmlessly with a routine eye examination. [Or] symptoms would most likely be their vision would be blurred and they would think they need new glasses, but then you discover [more] vision loss.
Do you see this problem often?
TS: Macular dystrophies are not very common. We see a lot of macular degeneration and age-related changes in the macula.
So we don't know exactly what Glenn Beck might have?
TS: No. He might also have macular corneal dystrophy, which is treatable. Assuming he has macular corneal dystrophy, that is a clouding of the cornea that can be treated and the most extreme treatment would be a corneal transplant.