What is Macular Degeneration?
Age related macular degeneration (ARMD) is a vision disorder caused by abnormalities in a portion of the eye’s retina called the macula. The macula is the small area of the retina which is responsible for fine or distinct vision, such as is required for reading. Degeneration of the macula usually results in gradual loss of central vision caused by damage to the light sensitive cells and pigment cells in the retina.
What are the Symptoms of Macular Degeneration?
Early symptoms of ARMD are blurred central vision and a waviness of straight lines. The blurriness may progress to blind spots, affecting reading, TV watching, and recognizing faces. Therefore, it robs affected individuals of their independence in their retirement years.
Who is at risk for Macular Degeneration?
Age is the single greatest risk factor for macular degeneration. An estimated 15 million Americans have decreased vision from ARMD. That number is expected to increase to by 50% by 2020. The prevalence of all forms of ARMD increases significantly with age. It affects approximately 17% of all individuals between the ages of 55 and 64, and the prevalence rises to 37% in those 75 and older. The more advanced, disabling forms affect 1 percent of Caucasian patients in their 50s, rising to more than 15% of those in their 80s. Approximately 1.75 million Americans have the advanced or late forms of the disease, exudative/wet ARMD and geographic atrophy/dry. Also, there are environmental, systemic diseases, and genetic factors associated with ARMD.
Cigarette smoking is the single most important modifiable environmental risk factor associated with the development of all forms of ARMD.
What are the Different Types of Macular Degeneration?
There are two stages of ARMD. Early macular degeneration is far more common, but late ARMD has a far greater impact on vision. Early macular degeneration is characterized by tiny clusters of soft, plaque-like deposits called drusen. Early ARMD progresses slowly and the central vision typically remains intact. Early disease can advance to late ARMD.
Late ARMD can be subdivided into the dry, or non-neovascular form, and the wet, or neovascular form. Dry ARMD is characterized by more extensive pigmentary abnormalities in the macula and by a somewhat extensive loss of pigment cells and vision cells in the central macula. It is called dry because it is not associated with abnormal blood vessels or leakage of blood or fluid.
Wet ARMD occurs in about 10% of patients who have late disease. It is characterized by an overgrowth of blood vessels just behind the macula. These abnormal blood vessels, technically described as choroidal neovascularization, leak blood or fluid or both into the macular which leads to damage of the vision cells or photoreceptor cells.
What Things can I Do to Influence Macular Degeneration?
Current and past smokers have increased risk of ARMD. Moderate or high blood pressure appears to be linked to wet ARMD. Nutritional supplements have been found to be effective in reducing the risk of ARMD vision loss in patients with moderate drusen. Lowering dietary fats may reduce the risk of advanced ARMD. Some studies show that aspirin and cholesterol lowering
statins may help prevent ARMD. Findings show that more frequent fish intake and high levels of omega-3 fatty acids reduce the risk. Blue light blocking sunglasses or intraocular lenses may also reduce the risk of macular degeneration.
What Treatments are Available for Macular Degeneration?
For forms of dry macular degeneration, one should control any systemic disorders, change their diet, wear UV protection glasses, and have regular comprehensive eye examinations by your eye care specialist. There have been numerous treatments for the wet form. If the neovascularization is not under the central macula, regular laser photocoagulation can be effective. Other types of laser include the Visudyne, which does not burn the retinal tissues. Treatment options for ARMD are expanding. Special drugs called anti-VEGF agents, Macugen, Lucentis and Avastin, are coming to market and show promise in halting the growth of the excessive and leaky blood vessels that damage the macula. Time will tell how well these new treatments work on wet degeneration.