Prevention of Blindness Society...

MACULAR DEGENERATION NETWORK NEWS

DECEMBER 1999

MACULAR DEGENERATION:

No Sure Cure, But Hopeful Studies Continue

Richard Garfinkel, M.D., a retina-vitreous surgeon and the Macular Degeneration Network’s medical advisor, opened the Prevention of Blindness Society’s Annual Meeting on November 20^th at Sibley Memorial Hospital with, "Nothing I see on the horizon is a cure right now." He told the crowd of 200 that Tom Brokaw has reported on the Nightly News that there is a cure for macular degeneration (AMD), but to date, that cure doesn’t exist.

Michael Osman, M.D., also a retina-vitreous surgeon and a colleague of Dr. Garfinkel’s, highlighted the current studies, their benefits and pitfalls. He started off by stating that

AMD is a degenerative disease that affects the macula, the portion of the retina that allows sharp, central vision. Wet AMD is the advanced form of the disease, which causes abnormal blood vessels to grow under the macula, leading to rapid vision loss.

Dr. Osman advises patients to regularly check vision with the Amsler Grid. If the lines look crooked that could indicate AMD. If there appears to be pieces of the grid missing, then wet AMD is a possibility. In either scenario, a prompt visit your eye doctor or a retinal specialist is in order. Dr. Osman also recommended that patients can benefit from eating spinach, broccoli, and kale. A daily multivitamin may also help, but he cautions that before patients start dietary changes or vitamin supplements that they check with their primary care doctor. Such changes might negatively affect other conditions.

An experimental study, PTAMD, is now underway. This study uses a low power laser to treat areas of drusen for those with dry AMD. The procedure takes five minutes during which the patient sees bright flashes of light. It is different than the traditional laser treatment, and has shown actual dissipation of drusen. In addition to its use as a treatment, PTAMD might also be useful as a preventive measure.

Conventional lasers can often treat wet AMD if the abnormal blood vessels are not in the central vision. To determine where the leakage is, fluorescein dye is injected. The dye will highlight where the leakage is occurring.

Dr. Osman compared responding immediately to signs of AMD to putting out a kitchen fire before it spreads throughout the house. Often retinal ophthalmologists don’t see patients until the leakage has spread to the central vision and the treatment and loss of vision is more complex and severe. This highlights the advantage of using the Amsler Grid daily to quickly notice changes in vision. If the abnormal blood vessels are in the central vision, then laser treatment will reduce bleeding and leakage, but does not improve central vision significantly.

For patients with wet AMD, photodynamic therapy has shown treatment benefits. The procedure begins by injecting photodynamic solution into a vein that highlights the abnormal bleeding vessels. The physician then uses a different type of laser. This laser is low-powered, and will not directly destroy the central vision, but does stop the bleeding. After photodynamic therapy, patients must avoid direct sunlight, because the solution is light sensitive. This procedure is pending FDA approval, which is expected approximately in mid 2000. This procedure is now only available under trial protocol.

Dr. Osman noted that for some patients with wet AMD, there is surgery available that removes the vitreous jelly in order to take out the abnormal blood vessels. This procedure is done in an outpatient setting, and takes between one to two hours. It is relatively painless, however occasionally during removal of the abnormal vessels some pigment cells are removed. Patients with large amounts of bleeding maybe the best candidates for this, however, the procedure does not significantly improve vision.

Macular translocation surgery involves detaching the entire retina in order to "translocate" the macula to a new area. If successful, the patient will have good results. However, in some cases the macula does not translocate, and sometimes the retina does not reattach causing a complete loss in vision. Other possible complications include folds forming in the macula or while detaching the retina, a hole or tear could occur. Both scenarios result in vision loss.

Patients with large lesions are not good candidates for translocation surgery or photo-dynamic therapy. For these patients, thermo therapy is a fairly new method that uses another laser beam to heat the blood vessels. This new procedure is still in trials.

© 2000 Prevention of Blindness Society of the Metropolitan Area, Washington, DC. All Rights Reserved.