Macular Degeneration (AMD)
The macula is the central part of the retina that has a very high concentration of cones. Our macula is used for our central vision, in fact, you are using your macula to read this passage. As we age, some patients develop an increasing atrophy or loss of function in their macula, leading to macular degeneration. Increasing age, oxidative stresses such as poor diet, poor circulation, and ultraviolet light may add to genetic factors, leading to macular degeneration.
“Dry” vs. “Wet” Macular Degeneration
There are 2 types of macular degeneration- dry refers to non-vascular and wet refers to vascular.
Dry macular generation occurs in about 85-90% of patients with macular degeneration. In this condition, the cells that support macular metabolism called the RPE (retina pigment epithelium) either are lost (called geographic atrophy), develop waste products called drusen or develop an increase in pigment (hyperpigmentation). It is not understood why these developments occur, but usually the changes slowly occur over several years. A landmark study called the AREDS1 and AREDS2 study proved that supplementing with Ocuvite Preservision vitamins reduced progression of certain types of dry macular degeneration. The role of omega 3s were only important in a small group of patients.
Wet macular degeneration is defined with the growth of abnormal blood vessels and subsequent leakage of fluid into the macula with a more sudden loss of central vision. 10-15% of patients with dry generation will progress to wet with time. Often wavy lines, blurry vision or missing areas are noted by the patient either with reading or on an Amsler grid. Prompt diagnosis and referral to a retinal specialist will help reduce the chances of visual loss now that there are monthly injectable medicines such as Avastin, Lucentis, Eyelea and others.
Although most cases of macular degeneration are genetic, modifiable behaviors include eating a diet rich in antioxidants (fruits and vegetables), supplementing with lutein, stopping cigarette smoking, exercising, and regular use of UV-protective sunglasses.