What is macular degeneration?
Age-related macular degeneration (AMD) is a medical condition which usually affects older adults and results in the loss of central vision because of damage to the retina, specifically the retina. AMD occurs in "dry" and "wet" forms. It is a major cause of blindness and visual impairment in older adults.
Who is at risk for developing macular degeneration?
Anyone over the age of 60 is at an increased risk of developing the disease. Approximately ten percent of patients between the ages of 65 and 75 will have signs of macular degeneration. The prevalence increases to thirty percent in patients 75 to 85 years of age. People with a family history of macular degeneration are at a fifty percent increased risk, and macular degeneration is more likely to be found in Caucasians than in people of African descent. Smoking, hypertension, excessive exposure to sunlight, and obesity are also factors that increase a person’s risk for developing the disease.
What is Wet AMD?
Wet AMD, as is it commonly known is actually neovascular or exudative AMD. This form of AMD causes vision loss due to choroidal neovascularization, or in layman’s terms, abnormal blood vessel growth, in the choriocapillaris, through Bruch's membrane, which leads to blood and protein leakage below the macula. Bleeding, leaking, and scarring from these blood vessels eventually cause irreversible damage to the macula and permanent vision loss if left untreated.
Thankfully, only about ten percent of patients suffering from macular degeneration have the wet type.
What is Dry AMD?
Dry AMD results from atrophy of the retinal pigment epithelial layer below the retina, which causes vision loss through loss of photoreceptors in the central part of the eye. There is no surgical treatment for this condition, but antioxidant vitamin supplements that build macular pigment, namely lutein and zeaxanthin, have been shown to slow the progression of dry macular degeneration and, in some cases, improve visual acuity.
The earlier macular degeneration is detected and the earlier the disease is treated, the better the outcome. What are some early warning signs people should look for?
People with dry macular degeneration may have no symptoms at all, or they may notice a gradual loss of central vision or blurry vision. Those with wet macular degeneration often notice a rapid onset of vision loss, shadows or missing areas of central vision and distorted vision known as metamorphopsia, in which a grid of straight lines appears wavy and parts of the grid may appear missing. This can be tested with a simple chart known as an Amsler grid.
All macular degeneration patients could have trouble discerning colors, specifically dark colors from other dark colors and light colors from other light colors.
There has been talk about the link between certain vitamins and minerals and the prevention of macular degeneration. Which nutrients should we be consuming (if any), and in what forms?
Adding certain nutrients to your diet every day, either through foods or through supplements, can help prevent or halt the progression of macular degeneration. Researchers have linked eye-friendly nutrients such as lutein, zeaxanthin, vitamin C, vitamin E, and zinc to reducing the risk of certain eye diseases, including macular degeneration. Recommended daily intake is 10 mg Lutein, 2 mg Zeaxanthin, 500 mg vitamin C, 400 mg vitamin E, and 40 to 80 mg of zinc per day to slow AMD progression.
What are some treatment options for macular degeneration?
While there is no cure for dry AMD, doctors now believe there is a link between nutrition and the progression of dry AMD. Dietary changes favoring low-fat content and dark green leafy vegetables can slow vision loss. Nutritional supplements including lutein, zeaxanthin, vitamin C, vitamin E, and zinc also may be beneficial in slowing or stopping the progression of dry AMD.
If detected early enough, wet AMD can be treated with a laser in a procedure called photocoagulation. A laser is used to seal the leaking blood vessels that damage the macula. Photodynamic Therapy (PDT) uses a medication injected into the bloodstream, which is then activated with a laser shone into the eye. A new therapy available, where a medication is injected into the back of the eye, is showing favorable results. These are not permanent cures but are used to slow the rate of central vision loss.
How successful are these treatments?
The success of these treatments depends on the severity of the condition when it was diagnosed.
Are there any new and exciting treatment approaches or technologies on the horizon?
While no current FDA-approved macular degeneration treatment is likely to completely restore vision loss caused by macular degeneration, a new drug, Lucentis, may be able to preserve or even improve remaining vision. Lucentis works by inhibiting proteins called vascular endothelial growth factor (VEGF), which stimulates the growth of new blood vessels in the body. VEGF is thought to contribute to development of macular degeneration by promoting the growth of abnormal blood vessels in the retina, particularly the macula.
What are the most common misconceptions that people have about macular degeneration?
Patients assume that if they are diagnosed with macular degeneration that they will automatically go blind. It is my job as their optometrist to provide them with the most appropriate care or refer them to the proper specialist for treatment.
Is there a cure?
Unfortunately, at this time, there is no cure for macular degeneration.