New Procedures for Macular Degeneration
The slow loss of clear vision is one of many cruel tricks nature plays on us as we age. Ophthalmologists can't turn the tide of Mother Nature, but they have found many ways to hold her back.
ge-related macular degeneration (ARMD) is probably the most common reason we lose clear vision as we age. The macula, or geographic center of the sensitive retina, allows us to see fine details clearly. As we age, the macula breaks down, causing blurriness or darkness in the center of our vision. The two most common types are atrophic (dry) and exudative (wet) macular degeneration.
There is no cure for patients suffering from atrophic macular degeneration, which is the slower, but more common type. Exudative macular degeneration means that abnormal blood vessels have broken through the macula, leaking fluid or blood into the eye. Vision loss is rapid and severe. Luckily, ophthalmologists are able to treat many patients with exudative macular degeneration.
Exudative Macular Degeneration
If the breakdown occurs away from the center of the macula, then traditional laser surgery usually can correct the problem. However, often the breakdown occurs under the center of the macula. Laser surgery is ineffective in those cases because, while it can stop the leakage, it also destroys the retinal tissue, which can decrease vision further.
As a result, researchers are constantly looking for new ways to help patients with exudative macular degeneration. Annapolis ophthalmologist and retina specialist David Watt, M.D., says, "Each year we investigate hopeful new procedures, but frankly, there are no miracle cures for most exudative macular degeneration." He said, however, he is optimistic about several new procedures that may help some patients suffering from exudative ARMD.
Limited Retinal Translocation
In this procedure, retinal surgeons detach the retina by injecting fluid under it, and move the retina about 1/20th of an inch so that a laser can reach the affected area without damaging the center of the retina. The eye wall is shortened and a gas bubble is injected to help reattach the retina. Dr. Watt said, "This procedure will only work for a small number of patients whose leakage occurs in exactly the right location. And because it's still in the experimental stage, we don't know the complications or the long term visual outcomes. We are hopeful about this procedure. We will be offering retinal translocation at AAMC for a select group of motivated patients with exudative macular degeneration."
Dr. Watt is much more optimistic about photodynamic therapy (PDT). This procedure, which is expected to receive Food and Drug Administration approval any day, is a promising laser therapy that treats exudative macular degeneration with less damage to the overlying retina. Ophthalmologists inject a photosensitive dye into the eye through the veins before applying a lower intensity laser. "The dye concentrates in the abnormal vessels growing under the retina. We can seal up the vessels that are under the retina while preserving the overlying retinal tissue. PDT will provide a possibility of restored vision to many more patients. Also, it's a form of laser therapy, which is a procedure we're already familiar with, and it doesn't have the surgical risks associated with it."
Transpupillary Thermotherapy (TTT) is an alternative therapy for patients with occult, or poorly defined, leakage. TTT uses the diode laser with an enlarged spot size and extended treatment time to treat leakage with less overlying retinal damage. TTT avoids the use and expense of the dye used in PDT. The preliminary results for TTT indicate the ability to stabilize vision loss in the majority of patients treated. TTT is already FDA approved.
Dr. Watt said, "I am currently using TTT in my office for patients with otherwise untreatable subfoveal occult leakage. I will be offering PDT when it is approved."