Macular Degeneration, Treatments for You and Judi Dench
If you or your loved ones have been diagnosed with age-related macular generation, you are among the estimated 20 to 25 million people around the world, like actress Dame Judi Dench, who is faced with the real possibility of losing your vision. If you are determined, like Dench has announced, to fight this disease, it is important to know about the available therapies and preventive measures against macular degeneration.
Macular degeneration is a major cause of blindness
Age-related macular degeneration is an irreversible destruction of the central region of the retina, called the macula. Damage to the macula leads to the loss of “straight-ahead” vision, the type of sight necessary to recognize faces, read, watch TV, drive, and perform activities that require sharp, detailed sight such as sewing or writing.
Macular degeneration occurs in two forms—wet and dry—and individuals can have both forms of the disease, either in one or both eyes. Dry macular degeneration is the more common type (85-90% of cases) and may progress and cause blindness without turning into the wet form. Wet macular degeneration is always preceded by the dry form.
Treating dry macular degeneration
Even though dry macular degeneration is much more common, most of the available treatments are for the wet form. However, there are some specific nutrients that have been shown to significantly reduce the risk of progression from the intermediate dry to wet macular degeneration. Let’s consider those first.
Based on the results of the National Eye Institute’s Age-Related Eye Disease Study (AREDS), many physicians recommend their patients with dry macular degeneration take high doses of certain nutrients, which have been shown to significantly reduce the risk of progressing from intermediate dry macular degeneration to advanced or wet disease.
The nutrients recommended include vitamin C (500 mg), vitamin E (400 IU), beta-carotene (15 mg), zinc (80 mg), and copper as cupric oxide (2 mg).
A new (January 2012) systematic review of the literature on macular degeneration and lifestyle modification reported that in addition to the nutrients recommended by AREDS, there is also evidence that the antioxidants lutein and zeaxanthin are “associated with a lower risk of prevalence and incidence” of age-related macular degeneration.
In addition, another recent study (July 2011) reported on the impact of dietary omega-3 fatty acids (found mainly in fatty fish) on age-related macular degeneration in the Alienor Study. The authors noted their findings confirmed “a decreased risk for ARM [age-related macular degeneration] in subjects with high intake of long-chain omega-3 PUFA [polyunsaturated fatty acids].”
Angiogenesis inhibitors for wet macular degeneration
Wet macular degeneration can be treated with angiogenesis inhibitors, which are given by injection into the jelly-like substance in the eye called the vitreous. These drugs afibercept (EYLEA™), ranibizumab (Lucentis®), and pegaptanib sodium (Macugen®). These drugs can stabilize vision in more than 90% of patients and may even improve vision in about 30%.
In wet macular degeneration, vision loss is caused by abnormal blood vessel growth that damages the macula. Angiogenesis inhibitors are designed to block the substances (proteins) that lead to that growth, which include vascular endothelial growth factor (VEGF) and placental growth factor.
All the angiogenesis inhibitors inhibit VEGF, while Eylea (the latest addition, approved by the FDA in 2011) also blocks placental growth factor. These injections must be administered every 4 to 8 weeks, depending on the drug (Eylea typically requires less frequent injections) and your specific needs.
Another angiogenesis inhibitor, bevacizumab (Avastin®), is used off-label for macular degeneration, although it was approved by the FDA for colorectal cancer. Lucentis, a form of Avastin developed by Genentech (which also makes Avastin), costs 20 to 100 times more than Avastin, although many doctors believe both drugs are equally effective.
Common side effects associated with angiogenesis inhibitors include conjunctival bleeding, eye pain, eye inflammation, blurry vision, cataracts, floaters, and increased intraocular pressure.
Other treatments for wet macular degeneration
Photodynamic therapy using verteporfin (Visudyne®) involves injecting a light-sensitive drug called verteporfin into a vein in the arm. A doctor then uses a cold laser directed at the retina to destroy the abnormal blood vessels and stop the development of new blood vessels. This painless treatment may stabilize vision but most likely will not improve it, and treatments must be repeated about every three months.
Laser photocoagulation involves high-energy laser that destroys abnormal blood vessels in the retina. Although this treatment can help prevent or slow additional damage, it also causes a permanent blind spot. Only a small percentage of patients with wet macular degeneration can be treated with laser photocoagulation because it cannot be used in people who have abnormal blood vessels under the center of the macula, which is where most vessels appear.
For individuals with severe wet macular degeneration, a possible treatment is an implantable miniature telescope, which was approved by the FDA in July 2010 (second-generation telescope). The procedure involves implanting the device into one eye, and the implant can then provide central vision in that eye. Post-marketing clinical trials are ongoing for this treatment.
Helping to prevent macular degeneration
Healthy lifestyle habits can help reduce the risk of developing macular degeneration. They include
- Do not smoke
- Eat a diet rich in fruits, vegetables, and fish
- Protect your eyes from too much sunlight by wearing sunglasses and hats
- Maintain a healthy blood pressure
- Exercise regularly
- Maintain a healthy weight
Use of low-vision aids and vision rehabilitation can help improve quality of life for individuals who have macular degeneration.
Macular degeneration is a life-changing, devastating disease that affects 11 million Americans, and that figure is projected to nearly double by 2050. You can join in the fight with Judi Dench against macular degeneration by taking preventive steps and talking to your doctor about treatments and clinical trials.
Chopdar A, Chakravarthy U, Verma D. Age related macular degeneration. BMJ 2003 Mar 1; 326(7387): 485-88
Macular Degeneration Research
Merle B, Delyfer MN et al. Dietary omega-3 fatty acids and the risk for age-related maculopathy: the Alienor Study. Invest Ophthalmol Vis Sci 2011 Jul 29; 52(8): 6004-11
Sin HP, Liu DT, Lam DS. Lifestyle modification, nutritional and vitamins supplements for age-related macular degeneration. Acta Ophthalmol 2012 Jan 23
Image: Courtesy Wikimedia Commons