Macular Disease
Macular Translocation Surgery
A very common cause of decreased vision, especially in patients with macular degeneration, is choroidal neovascularization (CNV). CNV means abnormal blood vessels are developing under the retina. If you imagine the retina as wallpaper lining the back wall of the eye, CNV represents abnormal blood vessels growing between the wallpaper and the underlying plaster. These abnormal blood vessels have a tendency to leak clear fluid or blood and generally grow, leaving a large scar under the center of the retina. When this scar forms, the central vision is severely impaired. The peripheral vision, however, is almost always preserved.
When CNV forms under the retina, doctors try laser treatment to seal the blood vessels closed to minimize the damage caused by scarring. Laser treatment for CNV is an effective, proven treatment. Unfortunately, laser treatment is not helpful for CNV that grows under the central focusing spot of the retina. The scarring caused by the laser will damage the focusing spot rather than protect it.
The goal of macular translocation surgery is to move the center focusing spot of the retina away from the CNV. This will then allow for laser treatment to be successfully performed on the CNV, without damaging the central focusing spot of the retina.
Laser Photocoagulation for AMD
Laser photocoagulation may be used to treat age-related macular degeneration (AMD). For this procedure, a laser produces a finely focused beam of powerful light.
During the treatment, the patient sits in front of the laser with his or her chin on a chin rest. After both eyes have been numbed by anesthetic eye drops, a contact lens is placed on the eye that is to be treated, and the laser beam is focused through it. Using photographs obtained from the fluorescein angiogram as a reference, the ophthalmologist aims the beam at the site of choroidal neovascularization (CNV). A burst of light is seen for a fraction of a second. When the laser's light is absorbed by the back of the eye, it is converted to heat, which clots the abnormal vessels. Laser treatments for AMD are not painful.
In approximately one-third of patients, the first treatment does not eliminate all of the abnormal vessels. Retreatment is then required. Each procedure takes approximately five to 15 minutes, after which the patient is allowed to go home. Blurred vision after laser treatment is normal. The patient may resume normal activities. The patient is usually requested to return for a followup examination, at which time a repeat fluorescein angiogram may be done to review the results of treatment.
Please note that even successfully treated patients must keep regular appointments with their ophthalmologist because there is a 50 percent chance of recurrent CNV.
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