Macular degeneration is a visually devastating disease that primarily affects poeple over the age of 75. Waste products produced by the retina are normally filtered out of the eye. In macular degeneration, however, the waste products are not properly filtered from the eye and are left in the retina. In early stages of the disease, pockets of waste product begin to build up in the outer layers of the retina. As the disease progresses, those pockets get bigger, leading to distorted vision. Eventually, the retinal tissue begins to die and tiny blood vessels start to grow into the retina in an attempt to keep the retina alive. Once these tiny vessels begin to grow, the macular degeneration becomes “wet macular degeneration” as opposed to “dry macular degeneration”.
Wet macular degeneration is the most visually devastating form of macular degeneration. It’s thought that if the formation of new blood vessels can be stopped, then vision will be preserved. So, in an effort to preserve vision, doctors have been injecting anti-growth hormone, called anti-VEGF, into the eyes of wet macular degeneration patients. The anti-VEGF targets the newly growing blood vessels and prevents them from growing more. Typically, patients will get anti-VEGF injections into the eye once every 1-3 months. Patients may be getting injections once a month for 1-2 years depending on their specific cases. Side effects of these injections are relatively low, but some patients report pain or discomfort. Because a needle is inserted into the eye in order to deliver the drugs, there is a potential risk of a bacterial infection in the eye which can have devastating consequences including blindness.
One way to avoid these potential complications is to find a drug delivery system that wouldn’t involve injection. Until now, there hasn’t been any drug that was able to penetrate through the cornea all the way back to the retina. Recently, there was an exciting study done on rat corneas that could possibly lead to a topical anti-VEGF drop. Scientists put a new compound onto rat corneas and were able to measure therapeutic quantities of it in the retinal tissue. While this study only shows that this new compound may be used as a carrier for anti-VEGF in the future, it is still quite exciting to think that one day macular degeneration could be managed with topical drops rather than injections! Until then, protect your maculas by wearing UV protection, not smoking and eating plenty of green leafy vegetables!