Treatment for Macular Degeneration
Currently, there is no treatment for dry macular degeneration. Quality of life can be maintained by the use of eyeglasses, magnifying glasses, closed circuit television, audio books, and reading material in large print.
Recent studies have shown that nutritional supplements (e.g., antioxidants, vitamins, minerals) may slow the progression of the disease and may help reduce vision loss.
Treatments available for wet macular degeneration include laser surgery (photocoagulation), photodynamic therapy, and injections (anti-VEGF therapy). Macular translocation surgery is an experimental procedure that may benefit some patients.
Laser Therapy to Treat Macular Degeneration
Ophthalmic surgeons use laser photocoagulation to treat leakage that results from neovascularization in wet AMD. Using flourescein angiography to pinpoint neovascularization, the laser beam burns abnormal blood vessels to seal the leakage. By slowing or stopping the leakage, the progression of macular degeneration is also slowed or stopped.
Unfortunately, only about one-tenth of patients with wet AMD are candidates for this procedure. In most cases, the abnormal blood vessels are located beneath the fovea (area of the macula responsible for detailed vision), and laser photocoagulation in that area would result in immediate and permanent vision loss. The leakage recurrence rate is about 50 percent with this procedure.
Photodynamic Therapy (PDT) to Treat Macular Degeneration
PDT is a minimally invasive outpatient procedure. Fluorescein angiography is used to determine which patients are candidates for this treatment.
The procedure involves a light-activated drug called verteporfin (Visudyne) and low-intensity, or nonthermal, laser light. The eye is numbed with eyedrops and a special contact lens is placed on the eye. The light-activated drug is administered intravenously. The laser light is directed through the contact lens to the affected area of the retina for approximate a minute and a half. Treatment closes up neovascular or leaky blood vessels.
Patients may require recurrent treatments as often as every 3 months for the first year, because neovascularization can recur. After the first year, treatment is required less frequently.
Side Effects of PDTAfter treatment, the skin and eyes are sensitive to bright light. Patients are advised to avoid exposure to direct sunlight or bright light for 5 days. Indoors, use curtains or shades to block out direct sunlight and avoid exposure to sunlight from skylights. If one cannot avoid going outdoors, the skin and eyes should be protected with a long-sleeved shirt or blouse, slacks, gloves, socks and shoes, sunglasses, and a wide-brimmed hat. Sunscreens do not protect the skin from photosensitivity reactions (e.g., sunburn) caused by verteporfin.
Injections (Anti-VEGF Therapy) to Treat Macular DegenerationWet macular degeneration also may be treated using medications that block the effects of growth factors, which promote abnormal blood vessel development in patients with AMD. In this treatment, first the eye is numbed and then the drug is injected into the eye. Patients with wet AMD usually require several injectionsmonthly, for exampleto reduce vision loss and improve sight.
Macular Translocation Surgery to Treat Macular Degeneration
Macular translocation surgery is an experimental treatment for wet macular degeneration that occurs beneath the fovea. Candidates for surgery have central vision loss in both eyes, with one eye having developed the condition within the past 6 months.
Patients with scarring on the macula, with long-term vision loss (longer than 6 months), extreme vision loss, and those with other eye diseases (e.g., diabetic retinopathy) do not benefit from the procedure. Significant risks are present with this treatment, including total vision loss.
LimitedThis technique involves putting stitches into the back wall of the eye (the sclera) to create a fold in the sclera. The fold causes the retina, which overlies the sclera, to wrinkle. The surgeon then flattens the retina over the buckle, which repositions the macula. The abnormal blood vessels are no longer under the fovea (central area of the macula) and can now be treated.
FullFull macular translocation involves first detaching the retina from the back wall of the eye. This is accomplished by first removing the vitreous from within the eye, placing fluid under the retina to lift it away from the sclera, and cutting the periphery of the retina. The retina remains attached to the optic nerve and is rotated 360°, which repositions the macula over healthy tissue. The abnormal blood vessels are either cut or treated with a laser, the edges of the retina sealed with a laser, and the eye filled with silicone oil to hold the retina in its new position.
An eye patch is worn the first day, which the surgeon removes the following day during the postoperative examination. The first 5 days after full macular translocation surgery, the patient spends 10 hours each day in special positions to facilitate retinal reattachment. Eye drops are used for a few weeks, and there are usually 4 follow-up visits during the first 6 months after surgery.
Because repositioning the macula produces tilted or double vision, 2 months after translocation a second corrective surgery is performed on the eye muscles. This, too, is an outpatient procedure.
Healing can take several months, and most patients will experience some degree of improvement. Reading vision usually is restored, but reading glasses or low vision aids may still be necessary.
Complications of Macular Translocation Surgery
Possible complications associated with macular translocation surgery include:
- cataract formation
- intraocular bleeding (bleeding within the eye)
- retinal detachment
- retinal tears
- vision loss
In July 2010, the U.S. Food and Drug Administration (FDA) approved an Implantable Miniature Telescope (IMT) to treat some patients with end-stage AMD. This device is implanted in one eye, replacing the eye's lens. Before undergoing this treatment, the patient must participate in an external telescope training program with a low vision specialist to make sure he or she has adequate peripheral vision in the other eye. Patients also must agree to take part in a visual training program following the procedure. Risks associated with the implant include damage to cornea, which may result in the need for corneal transplant. Additional studies regarding IMT to treat macular degeneration are being conducted.