When Dr. Mark Kleinman was offered the chance to come to the University of Kentucky Department of Ophthalmology and Visual Science for a fellowship in vitreoretinal surgery, he didn’t hesitate. “The university has one of the top eye research centers in the world led by Dr. Jayakrishna Ambati,” he says, “and I wanted the opportunity to work with such a strong team.” That team also includes Drs. Andrew Pearson, Sheila Sanders, and Woodford Van Meter, all of whom were recently named among the best doctors in the United States. High on the research team’s list of priorities — finding a way to beat Age-Related Macular Degeneration (AMD).
The macula is a layer of light sensitive tissue in the center of the retina. It is what enables us to distinguish certain colors, discern fine details, and notice contrasts. Macular Degeneration is the breaking down of that layer of tissue. There are two distinct types of the disorder. Wet Macular Degeneration occurs when blood vessels leak fluid or blood underneath the retina. Dry Macular Degeneration occurs when the cells that comprise the macular tissue break down and disintegrate.
As of 2010, according to the National Eye Institute, an estimated 2,000,000 Americans suffered some form of AMD, which is the leading cause of vision loss in the nation. While many suspected cases are referred by optometrists, there are a number of warning signs that family physicians should be aware of, especially since early detection is key. These warning signs include:
- Age. Most cases occur in people over 50.
- Family history. There is growing evidence that more than 50 percent of those with AMD have a genetic predisposition to the disease.
- Tobacco use. Smoking increases the risk of developing the advanced forms of the disease nearly four-fold.
- Auto-immune diseases such as Rheumatoid Arthritis or Lupus. Some medications used to treat these diseases, such as Plaquenil, may increase the risk of toxicity in the retina resulting in early-onset macular degeneration.
AMD is usually painless but a range of symptoms may develop, including blurred vision, distorted images, difficulty noticing colors or contrasts, or the presence of blood in the eye. Since AMD looks different in every patient, Kleinman emphasizes the importance of an ophthalmologist referral sooner rather than later.
To make a diagnosis, the ophthalmologist will collect a detailed medical history of both the patient and family members. This is followed by a set of vision tests, dilation, and other exams to inspect the retina. For example, a Spectral-Domain Optical Coherence Tomography (SD-OCT) is a non-invasive imaging procedure that provides a series of detailed cross-sections of the retina, thereby allowing the specialist to look for disruptions in the retinal tissue layers and other abnormalities. An Amsler grid test can check for distorted vision and be used at home by the patient to remotely monitor for the development of sub-retinal fluid. Also, an angiogram may be performed, injecting dye into the arm so that its path into the eye may be followed, checking for the abnormal blood vessels that are linked to Wet AMD.
But what of treatment? Any prescribed plan will depend largely upon two key factors: the type of AMD (wet or dry) and the level of advancement. As always, the earlier AMD can be detected, the earlier a plan of action can be put into place. Sadly, there is no treatment to reverse the effects of Dry AMD, although that is the focus of an intense translation research program at UK. However, the ophthalmologist will recommend ongoing checkups to track any vision deterioration. He or she may also suggest a course of vitamins and supplements to help slow the condition’s progression depending on clinical staging of the disease. Similar regular checks will be required with a diagnosis of Wet AMD. In addition, recombinant antibody technology can help slow the disease’s progression or perhaps even reverse some vision loss. Kleinman estimates that, after beginning treatment, one third of patients with Wet AMD respond very well and regain significant vision (3-lines or 15 letters) while one third will eventually go blind (20/200 or worse) in the affected eye.
While those odds may not be ideal, they offer hope to millions. Meanwhile, patients can rest assured that Kleinman and his colleagues are working hard to improve those odds for everyone.
By Fiona Young Brown, Editor