Macular Degeneration is an inherited deterioration of the Macula. Macular degeneration is the number one cause of permanent vision loss in the United States in those over 65 years of age. The macula is a small area of the retina in the back of the eye that is responsible for the fine vision that we use for reading and driving. The very center of the macula is the fovea. This is a ~1.5 mm area that allows us to see 20/20. Without this area, we are only able to see the “big E” or 20/400. Even though macular degeneration can rob us of our central or reading vision we maintain our peripheral vision and do not go completely blind.
Two types of Macular Degeneration
- Dry (Atrophic) Macular Degeneration
- All Macular Degeneration starts out as Dry Macular Degeneration. Dry Macular Degeneration is a slow deterioration of the macula over time. Vision loss typically occurs slowly over many years. The hallmark clinical signs of Dry macular degeneration are Drusen, Retinal Pigment Epithelial (RPE) Changes and RPE Atrophy. The amount of these clinical signs are used to divide Dry macular Degeneration into Mild, Intermediate and Severe categories. Approximately, 10% of individuals with Dry macular degeneration will progress to Wet Macular Degeneration.
Dry Macular Degeneration
- Wet (Neovascular) Macular Degeneration
- Wet Macular Degeneration occurs when new blood vessels grow into the retina. These are abnormal blood vessels and they are leaky (Like a garden soaker hose). They leak serum and often blood into and underneath the retina. This extra fluid causes the retina to swell and no longer function correctly, resulting in a decrease in vision.
Wet macular degeneration with hemorrhaging and edema
Testing We use two types of photography to demonstrate the new, abnormal blood vessels and the swelling in the retina. We use IVFA (intravenous fluorescein angiography) where fluorescein dye (vegetable dye) is injected into a vein and circulates through the eye to highlight and display the abnormal blood vessels. OCT (Ocular Coherence Tomography) is used to display the amount of swelling (edema) in the retina.
OCT - wet AMD