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| Screen And Diagnosis Of Age Related Macular Degeneration |
The eye examination includes a simple test of your central vision using an Amsler grid. If you have macular degeneration, when you look at the grid some of the straight lines may seem faded, broken or distorted. By noting where the break or distortion occurs - usually on or near the center of the grid - your eye doctor can better determine the location and extent of your macular damage.
This helpful test can be done outside a doctor's office. If you're looking for early symptoms of macular degeneration, you can administer the test yourself at home.
To evaluate the extent of the damage from macular degeneration, your eye doctor may use fluorescein angiography. In this procedure he or she injects fluorescent dye into a vein in your arm and takes photographs as the dye passes through blood vessels in your retina and choroid. Your doctor then uses these photographs to detect changes in macular pigmentation or the existence of abnormal blood vessels in your macula that may not be visible to the bare eye.
Treatment
Currently there's no treatment for dry macular degeneration. However, this doesn't mean you'll eventually lose all of your sight. Dry macular degeneration usually progresses slowly, so many people with this condition are able to live relatively normal, productive lives, especially if only one eye is affected.
If you have wet macular degeneration, some treatment options are available. But the success of the treatment depends on the location and the extent of the abnormal blood vessels, or choroidal neovascularization (CNV). Be aware that successful treatment means stopping further progress of the disease. In most cases the damage already caused by AMD can't be reversed. The sooner CNV is detected, the better your chances of treatment preserving what's left of your central vision.
The three treatments currently available are photocoagulation, photodynamic therapy (PDT) and macular translocation surgery, each of which can be done as an outpatient procedure. Experimental procedures using an infrared laser (transpupillary thermotherapy, or TTT) or radiation therapy are being tested but are still unproven to benefit people with macular degeneration.
Photocoagulation
Photocoagulation can seal off and destroy the CNV that has developed under your macula. It can prevent further damage to the macula and halt continued vision loss. Only about 20 percent of people who have wet macular degeneration are candidates for this procedure. Whether it's right for you depends on the location and appearance of the CNV, the amount of blood that has leaked, and the general health of your macula. Even if photocoagulation is a viable option for you, the results can be disappointing. Laser surgery to destroy the CNV is successful only about 50 percent of the time. And even successfully destroyed CNV has a tendency to recur. Repeat laser treatment may not be possible in such an event.
If you noticed a dark or gray spot in or near your central vision before laser treatment, the procedure will make vision in that spot completely and permanently blank. With time you may not notice the blank spot any longer, especially when you use both eyes. And if you closely monitor your vision and have frequent follow-ups with your doctor, you're likely to retain more sight than if you had received no treatment at all. Photocoagulation is the only proven treatment for CNV when it's not located directly under the fovea at the center of your macula.
Photodynamic therapy
Photodynamic therapy (PDT) is a new treatment for CNV that's located directly under the fovea. The fovea lies at the center of your macula and in healthy eyes provides your sharpest vision. If conventional hot-laser surgery were used at this location, it would destroy all central vision. PDT increases your chances of preserving some of that vision.
This procedure combines a cold laser and a light-sensitizing drug that's injected into your bloodstream. The drug concentrates in the CNV under the macula. When the doctor directs cold laser light at it, the drug releases substances that close off the abnormal blood vessels without damaging the macula, and the CNV transforms into a thin scar. The overlying rods and cones are largely preserved, resulting in better vision than if you had had hot-laser surgery or no treatment at all. The therapy can be repeated if the CNV doesn't close or if it reopens after initial closure.
The Food and Drug Administration recently approved the drug verteporfin (Visudyne) for use in photodynamic therapy. Studies involving verteporfin demonstrate that over a 2-year period, multiple treatment sessions reduced vision loss for two-thirds of the people who had clearly defined CNV under the fovea. Though these results are promising, other long-term benefits are still under study. For example, further research will determine if this treatment also helps people who have poorly defined or hidden areas of CNV.
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| Screen And Diagnosis Of Age Related Macular Degeneration |
Macular translocafion surgery
Macular translocation surgery is an experimental treatment for wet macular degeneration. This surgery can be used if the abnormal blood vessels are located directly under the fovea. To start the procedure, the surgeon detaches the retina, shifts the fovea away from the CNV and relocates it over healthy tissue. When the CNV is exposed, the surgeon can then use a hot laser to destroy blood vessels without damaging the fovea. This surgery can be performed only if your vision loss is recent (usually within 1 to 3 months), the extent of CNV is limited and the tissue around the fovea is healthy. To find out more, you can check out Screen And Diagnosis Of Age Related Macular Degeneration.