Probably the most dreaded two words uttered in our office is "macular degeneration". This condition strikes fear the moment it is spoken. Macular degeneration is associated with severe loss of vision and dramatic impairment in function.
There are two types of age-related macular degeneration (ARMD) - dry and wet. Dry ARMD results from a deterioration of the thin layer of cells at the back of the eye called Bruch's membrane. This layer essentially separates the blood supply of the retinal and its nerve layer. In the area of the macula (latin word for "spot"), the nerve fiber layer is so tightly packed (to afford the best vision) that there is no space for many blood vessels. So the capillary layer behind this membrane "oozes" nutrients which are usually conducted across the membrane to nourish the nerve cells and surrounding tissue. For reasons which are not, even yet, entirely clear, this membrane will become lumpy. In doing so, the lumps (also called drusen - german word meaning rubbish or trash interestingly) distort the retina above it and disturb the vision.
If the membrane develops a leak and allows some of the "ooze" to go through to the nerve fiber layer, it occupies space, there is inflammation and a scar usually results. This is so-called "wet" macular degeneration.
Dry ARMD is a slowly progressive condition, tending to run in families like many diseases, and there is not apparent cure for it. It is thought that the "trash" might be products of metabolism that get caught between the layers so an hypothesis that antioxidant vitamins might help to prevent or at least slow the progress of the condition. The AREDS (Age Related Eye Disease Study) conducted some years ago by the National Eye Institute, seemed to indicate that vitamin/mineral products containing Vitamins A, C and E, and Lutein and Zeaxanthine, were capable of making a difference IF used during certain phases of development of the disease but not all. We feel that vitamins can't really hurt if taken at appropriate dosages, so we recommend them.
Wet ARMD, formerly the scourge of Ophthalmology because it proceeded rapidly and disastrously to blindness, can now be treated if caught early enough. Certain cancer fighting drugs, Avastin and Lucentis, can be injected into the eye (not as bad as it sounds) and macular damage can be arrested. Scar tissue is not reversed with these medications, but fluid and blood can be made to resorb using them, demonstrating how important early diagnosis is. So now, we actually have an effective treatment for wet ARMD caught early enough, before significant scarring has occurred.
To help up help individuals susceptible to ARMD, genetic testing is now available. It helps to predict whether an individual will get ARMD in the future. There are presently five (5) genetic markers known to be associated with ARMD, some of them more than others. A simple genetic test (if you watch CSI you have seen the cheek swab used to collect genetic material) can be done to detect these markers. Some controversy exists as to the actual value of this test, but if nothing else, it prompts closer patient monitoring, advice to avoid smoking and alcohol consumption (which seems to increase risk), use of AREDS vitamins and genetic counseling.
Certainly, more is expected about this subject from ongoing research. We'll keep you informed.