Forms of Macular Degeneration
Macular Degeneration and Age-Related Macular Degeneration occurs in two main forms: a “dry” or atrophic type and a “wet” or exudative type. Everyone with macular degeneration initially has the dry form and every person with macular degeneration develops the disease in both eyes, however, one eye can worsen more quickly than the other. The dry form of AMD is NOT one disease; there are four major groups of dry AMD. The first three are classified by the size of the small yellow spots (called drusen) that develop in the layer of cells underneath the retina. Drusen come in three sizes: small, medium and large. Patients with small drusen have an excellent chance of keeping good vision during their lifetime. Patients with medium or large drusen have a much higher chance of developing the wet form of macular degeneration, especially if their drusen are associated with small clumps of brown pigment. Patients with medium or large drusen are considered to have “HIGH-RISK” dry AMD. The fourth type of dry macular degeneration is called geographic atrophy, in which the cells underneath the retina slowly wither away. Geographic atrophy only rarely changes into wet macular degeneration, however, it can cause a person to become legally blind if the disease affects the cells underneath the very center of the macula.
Preventive Measures for Macular Degeneration
Treatment for dry macular degeneration depends upon the type of disease present in a patient. All patients with dry macular degeneration should have a coating on the lenses of their eyeglasses to block the ultraviolet rays from the sun. Sunglasses are helpful when outdoors. A daily multivitamin with antioxidants, lutein, zeaxanthin, and zinc may slow the progression of high-risk dry AMD and wet AMD. We do not recommend taking more than 80 mg of zinc per day because this may be harmful to the retina and other organs.
Diagnostics for Macular Degeneration
Although only 10% of patients with AMD will develop the wet type of degeneration, 90% of the patients with severe visual impairment have this form of the disease. In wet AMD, fluid builds up under the retina. Abnormal new blood vessels that grow like tiny weeds under the retina cause this fluid. The fluid can be seen during a retinal examination and documented with a noninvasive test called Ocular Coherence Tomography (OCT). The abnormal blood vessels and the leakage they cause are visualized using a safe intravenous dye test called a fluorescein angiogram. Without treatment, the blood vessels will eventually form a scar and lead to permanent loss of the central vision.
Treatments for Macular Degeneration
Some patients with high-risk dry AMD may be eligible for a new laser treatment that can cause the medium and large drusen to disappear within 6 months. Recently the laser treatment has proven to have a significantly beneficial effect on vision in two different well-designed studies. It has yet to be determined from the studies whether the laser treatment will reduce the risk of a patient getting the wet form of AMD; however, this information should be available soon. The new laser treatment for high-risk dry AMD is painless, takes less than 5 minutes and is performed in the office. Approximately 20 very mild laser spots are placed in a semicircular grid pattern around the edge of the macula. Most patients do not even notice the laser spots after treatment; if they are noticeable, the spots usually fade away within 10 days. If both eyes require treatment for the laser, they are treated about a week apart. The patient is asked to return for an exam and fluorescein pictures at 3 months and 6 months after the treatment. If the drusen have not regressed sufficiently after 6 months, another laser treatment may be repeated on the opposite side of the macula.
Every patient with dry macular degeneration is given a special chart with a checkerboard grid pattern called an Amsler Grid. The Amsler Grid that your Retina Specialist gave you has the instructions printed on the back. It is crucial for a patient with macular degeneration to look at his/her grid every day. The proper way to look at the grid is to hold it at a reading distance (with your reading glasses on) and cover one eye at a time. While looking at the round dot in the center, you’re verifying that all the lines appear straight. Some patients with dry macular degeneration may have a few wavy lines on the Amsler Grid; as long as the appearance of the grid does not change from day to day, there is no cause for concern. However, if the lines suddenly become more distorted or lines that were previously straight become wavy, then call the office IMMEDIATELY. We will make every effort to see you in the office within 24 hours. It is very important to understand any sudden noticeable change in the appearance of the grid almost always means there is a problem in the macula and we consider it to be an emergency.
Obviously, at this point in time, there are as many different approaches to treating wet AMD as there are retina specialists. At The Eye Institute, we individualize the treatment to best fit the patient and one doctor will often employ different approaches depending upon the situation. Your physician may even suggest switching medications if the circumstances warrant it. Since there are so many treatment options, it is imperative for you to be well informed. Our Retina Specialists will carefully review your choices and, working together, will devise a treatment plan that will best serve your needs.
Ongoing research investigating the causes and treatment of AMD remains one of the major efforts of the ophthalmology community. Dr. Kirsch is the Principal Investigator for the evaluation of two new potential medications for wet AMD. The results of the studies should be available in the near future. The Eye Institute of West Florida is committed to providing our patients with every opportunity to benefit from the most advanced and current treatments available and will continue participating in clinical research studies in the future.
Leonard Kirsch, MD and Richard Hairston, MD were the first Retina Specialists in the Tampa Bay area to offer these new treatment options for patients with wet macular degeneration.
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Meet Your Retina Care Specialists
Leonard S. Kirsch, M.D., F.R.C.S.(C) is a fellowship-trained vitreous and retina specialist. He is internationally known for the numerous papers and lectures he has presented here and abroad. Dr. Kirsch is currently an active participant in ongoing research to find new treatments for diseases of the retina. His expertise in the most advanced diagnostic and treatment techniques of all diseases of the retina, macula, and vitreous make Dr. Kirsch one of the elites in his field. In the Tampa Bay area, Dr. Kirsch pioneered the use of Photodynamic Therapy with Visudyne©, and intravitreal Macugen©, Lucentis©, and Avastin© for the treatment of age-related macular degeneration. Dr. Kirsch was also among the first surgeons in Florida to perform 25 gauge “no-stitch” vitrectomy in 2001. He is certified by the American Board of Ophthalmology and is a fellow of the Royal College of Surgeons of Canada.
Richard J. Hairston, M.D. is a vitreous and retina specialist. He joined The Eye Institute in June 2001 coming to us from a busy retina practice in Washington, DC. Dr. Hairston graduated from the Johns Hopkins University School of Medicine and did his residency at the Wilmer Ophthalmological Institute at Johns Hopkins University. He completed a fellowship in diseases and surgery of the retina and vitreous at The Center for Retina Vitreous Surgery, Memphis, Tennessee. He then served as Assistant Chief of Service in Ophthalmology and Director of the Ocular Trauma Service at Johns Hopkins Hospital. Most recently he was Assistant Professor of Ophthalmology at Johns Hopkins University. He is certified by the American Board of Ophthalmology. Dr. Hairston enjoys an international reputation as an outstanding retina and vitreous surgeon.
Janie Ho M.D., is a board-certified ophthalmologist, fellowship-trained in medical and surgical vitreoretinal diseases such as macular degeneration, diabetic retinopathy and retinal tears and detachments. She has been educated at some of America’s finest institutions. She received her Bachelor of Arts from Harvard University and her medical degree from Duke University. She went on to ophthalmology residency at the University of California, San Francisco. Following residency, Dr. Ho continued on to a fellowship in vitreoretinal diseases at the prestigious Massachusetts Eye and Ear Infirmary of Harvard Medical School. Dr. Ho has participated in angiogenesis research, investigating causes and treatment for common retinal disorders.