Age Related Macular Degeneration (AMD) affects millions of people worldwide, most of them elderly. It is a leading cause of vision loss and can significantly impact a person’s quality of life, but continuing medical developments offer new hope in the treatment of this debilitating condition.
“In my 30 years of practice, I’ve never been more excited about the advances in treatments coming our way,” said Dr. Adam M. Katz, an ophthalmologist at Center for Advanced Eye Care.
“AMD affects central vision, making it difficult to drive or recognize faces and up until about 18 years ago there was no effective treatment. Laser therapy, radiation and surgery simply weren’t successful. But with the advent of injectable medications, it’s a different world in which the progression of the disease can be slowed and, in some cases even improved.” New medications are being approved on a regular basis.
There are two types of AMD: Wet and dry.
According to the Academy of Ophthalmology, dry macular degeneration, also known as atrophic or non- neovascular macular degeneration, is the more common form of the disease, accounting for 80-to-90 percent of cases. It occurs when the light-sensitive cells in the macula, the central part of the retina responsible for detailed vision, gradually break down, resulting in a loss of vision.
Wet Macular Degeneration, also called neovascular macular degeneration, is less common but more severe than the dry form. It arises when abnormal blood vessels grow beneath the retina. These fragile vessels can leak fluid or blood, causing sudden and rapid vision loss in the central vision.
“Every case of wet started with a case of dry,” Dr. Katz explained. “All those changes with dry is predisposing to the growth of abnormal blood vessels. Dry AMD progresses slowly and can turn into wet AMD but there are patients who never develop the wet form who [still] end up being legally blind. What happens is geographic atrophy or loss of cells. It’s kind of like a sidewalk that starts developing cracks. Those cracks predispose to the growth of weeds. If you never get weeds in the cracks, it is the dry form. But if the weeds grow through the cracks like abnormal blood vessels it’s the wet form.”
Happily, wet macular degeneration has been effectively arrested with the introduction of anti-VEGF therapy. VEGF stands for vascular endothelial growth factor, a protein that stimulates the growth of abnormal blood vessels. Anti-VEGF drugs are injected into the eye to block VEGF, preventing the growth of these vessels and reducing leakage. These drugs have shown remarkable efficacy in slowing down vision loss and in some cases improving vision.
“Getting a shot in the eye sounds horrific but in fact it is very tolerable,” said Dr. Katz. “I’ve given over 10,000 injections and most patients ask if that’s all it is when I’m done. The basic protocol is one injection spaced a month apart for three months. After the injections, the patient has either active or inactive macular degeneration. If they are active, there is still a lot of fluid in there and regular injections are needed.
“If the patient is inactive there are three options:
“One is to treat and maintain, meaning you may need an injection every six to eight weeks to maintain.
“The second is to treat and extend the intervals between shots with each injection. The patient may get one shot in a month and another in six weeks and another in eight weeks.
“The third option is to treat as needed. If the patient’s [disease] is inactive, I don’t recommend another injection. Instead, I have them come back in another six weeks and get reevaluated. I don’t do another injection unless it becomes active. My goal is to give as few as possible, and typically patients need them less and less. As new medications become available the time between injections may be extended. [However] it’s important to remember that these injections are treatments and not a cure.”
Just three months ago, the FDA approved a new treatment for a specific form of dry macular degeneration. Syfovre is a prescription eye injection used to treat geographic atrophy (GA), the advanced dry form of macular degeneration.
GA can progress when a part of the immune system in your eye overworks and mistakenly damages your retina. It’s called geographic atrophy because the expanded area of the atrophy or loss of cells can resemble a state or country.
“Syfovre is a bit controversial,” Dr. Katz explained. “The injection is given once a month or every two months and studies show that after three years it slowed the progression of the expansion of the atrophy by about 20 percent. But the downside was that after three years there was no difference in visual acuity. It didn’t make you see better. And it increased the chance of developing the wet form of macular degeneration.
“It’s not for everyone, but for someone who has lost their central vision in one eye and the other eye has vision threatening geographic atrophy, I think it makes sense to consider the treatment because slowing down the expansion of the atrophy is better than doing nothing.”
A more promising treatment for GA could be right around the corner, with FDA approval of a drug called Zimura expected by August. The American Academy of Ophthalmology states that Zimura is an injectable drug that “works in the compliment pathway where it directly inhibits formation of substances that cause cell death.”
“Zimura has been shown to decrease the rate of vision loss by 56 percent, which looks like a better treatment option to me,” Dr. Katz said.
Researchers are also investigating gene therapy as a potential treatment for AMD. In this approach, genes are delivered to the retina to counteract the underlying genetic factors responsible for the condition. By targeting specific genes, scientists aim to restore or preserve the health of retinal cells.
Stem cell therapy is another avenue being explored for both dry and wet AMD. Researchers are investigating how to harness the power of stem cells to replace damaged retinal cells and restore vision.
While this field is still in its early stages, gene therapy and stem cell therapy are promising approaches that offer hope for both dry and wet forms of the disease.
“For a long time, I could only slow the progression of the disease, but now I can actually help some of my patients see better,” said Dr. Katz. “The advancements being made in the field of AMD research provide optimism for the future.”
Dr. Adam M. Katz is board certified by the American Board of Ophthalmology and dual fellowship-trained in disorders of the retina and vitreous. He was awarded his medical degree from Albany Medical College in New York and completed his internship in internal medicine at Lenox Hill Hospital in New York City. He completed his residency at Saint Vincent’s Hospital in Manhattan and retina fellowships at NYU and a second one in Memphis. He can be reached at Center for Advanced Eye Care, 3500 U.S. 1, Vero Beach, 772-299-1404.
