Conventional Treatments
The conventional treatment for macular degeneration may be divided into:
- Prevention
- Wet treatment
- Visual aids
Prevention
Presently, no standard agreement on preventing macular degeneration is known. The risk factors that can be altered may provide a starting point for some patients. Patients with ARMD should stop smoking. Good eating habits with plenty of antioxidants from vegetables and fruits is a growing trend that is supported from some studies. Eating spinach and collard greens five or more times a week was found to noticeably reduce the risk of ARMD. The carotenoids lutein and zeaxanthin are found in these vegetables in addition to other dark green leafy vegetables such as kale, mustard greens, and turnip greens (Seddon JM et al. JAMA. 1994; 272: 1413-1420). A dietary supplement that includes high levels of antioxidants and zinc significantly reduces the risk of advanced age-related macular degeneration (AMD) and its associated vision loss. These findings from a national clinical trial sponsored by the National Institutes of Health appear in the October issue of the journal Archives of Ophthalmology. Based on the results of this study, researchers now say that people over 55 who have findings on dilated eye exams that indicate intermediate age-related macular degeneration should consider taking a supplement of antioxidants plus zinc to delay progression of disease. "Truthfully, a lot of us were surprised that the supplements were as effective as we saw," says Fredrick Ferris, MD, director of clinical research at the National Eye Institute and chairman of the Age-Related Eye Disease Study, or AREDS, of which this study is one part. "We designed the study to find a small-to-moderate effect, and when we found that 25% of people at risk for AMD were getting a protective effect--well, that's pretty remarkable."
Ferris and his colleagues designed the study so that they could test the effects of antioxidants alone and zinc alone, and then the two combined.
"The antioxidants had an effect, and the zinc had an effect, but together they had a greater effect than the sum of their individual effects combined," says Ferris.
The researchers studied 3,640 people aged 55-80 years for an average of 6.3 years who were evaluated for signs of AMD, the leading cause of vision loss in people over age 65. The researchers evaluated the effect of high-dose vitamins C and E, beta-carotene, and zinc supplements on AMD progression and visual acuity. They found that participants with signs of early AMD who took antioxidants plus zinc significantly reduced their risk of developing advanced AMD.
The participants were divided into four categories based on preexisting eye lesions and degeneration present before the study, roughly corresponding to their risk of AMD progression. They were evaluated every 6 months for retinal changes indicating AMD progression. The participants were randomly assigned to receive one of four daily supplements that included various combinations of vitamin C, (500 milligrams--mg); vitamin E (400 International Units--IU); beta carotene (15 mg); zinc (80 mg, as zinc oxide); and copper (2 mg, as cupric oxide). These groups were measured against a placebo group.
In their report on the study, Ferris and colleagues wrote that of the groups, "the only statistically significant reduction in rates of at least moderate visual acuity loss occurred in higher-risk persons assigned to receive anti-oxidants plus zinc [a 27% reduced risk]."
The authors also noted that the doses of vitamins C and E and the dose of zinc used in the study are higher than the recommended daily amount and therefore can only be obtained by taking supplements. One such supplement is "ICAPS" which contain some of the critical vitamins and minerals noted in the study. TOP
| Vegetables |
Antioxidant Value
(Oxygen Radical Absorbance Capacity - ORAC)
ORAC units per 100 grams |
| Kale | 1770 |
| Spinach | 1260 |
| Brussels sprouts | 980 |
| Alfalfa sprouts | 930 |
| Broccoli flowers | 890 |
| Beets | 840 |
| Red bell pepper | 710 |
| Onion | 450 |
| Corn | 400 |
| Eggplant | 390 |
| Fruits |
Antioxidant Value
(Oxygen Radical Absorbance Capacity - ORAC)
ORAC units per 100 grams |
| Prunes | 5570 |
| Raisins | 2830 |
| Blueberries | 2400 |
| Blackberries | 2036 |
| Strawberries | 1540 |
| Raspberries | 1220 |
| Plums | 949 |
| Oranges | 750 |
| Red grapes | 739 |
| Cherries | 670 |
| Kiwi fruit | 602 |
| Grapefruit, pink | 483 |
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Wet Treatment
The standard treatment for the wet form of ARMD is laser. The ophthalmologist performs a fluorescein angiogram to help identify the exact location of the blood vessel and determines if the blood vessel is treatable or not with conventional laser. The Macular Photocoagulation Study (MPS) has defined the parameters of conventional laser treatment as well as the success rates. Generally, the principal goal is to heat the blood vessel to close it. Unfortunately, a side affect of laser is the destruction of the overlying retina, and hence the treated area is no longer able to function. If this treated area happens to be in the fovea or just adjacent to it, significant visual loss may occur, possibly to the level of legal blindness.
The success of laser treatment is dependent on several factors. Localization of the blood vessel is essential for successful treatment. If the blood vessel is not accurately localized, then larger treatment areas may need to be covered, resulting in unnecessary loss of vision. If the CNVM is under the fovea, significant visual loss occurs with treatment; however, leaving the CNVM alone will also cause visual loss. The MPS showed patients with this type of wet macular degeneration benefit from the laser at the 4-year follow-up. The drawback is the immediate loss of vision from the laser. |
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Laser is performed as an outpatient procedure. A follow-up visit with a repeat of the FA is arranged 2 - 3 weeks after the laser. TOP
Photodynamic therapy (PDT) is a technique where a drug is activated at a certain frequency of light. Several PDT drugs are presently in development. The drug is administered intravenously and a laser is directed into the eye in a similar fashion as used in conventional treatment. There is a tendency for the drug to collect in newly formed blood vessels. Once the laser activates the drug, a local reaction occurs within the new blood vessel to close it off without creating the damage of a conventional laser. Clinical trials have been performed with some promising results in a selected group of patients with subfoveal (underneath the fovea) CNVM. Final approval for one of this class of drugs should be given this year.
Visudyne Therapy is the first light-activated drug treatment available for patients with Predominantly Classic subfoveal CNV. The procedure begins by having your pupil dilated and anaesthetized with eye drops. This is followed by an intravenous injection of Visudyne into your arm. The Visudyne travels throughout your bloodstream and, when it reaches your retina, collects in the abnormal new blood vessels. Once there, your Doctor will activate the drug by shining a non-thermal laser (a laser that does not burn the retina) on the back of your eye.
This produces a clot that closes the abnormal vessels with no damage to the overlying sensory retina reported. The clot then stops the harmful leakage of blood and fluid into the retina, stabilizing vision. The abnormal blood vessels may return after several months. However, photodynamic therapy can be reapplied at up to 3 monthly intervals if necessary. TOP |
Visual Aids
Visual aids may be used in both the dry and wet forms of ARMD. The visual aids include magnifiers, computer assistance magnification, and large print books. In the beginning of the disease, trial and error with hand-held magnifying glasses is usually the most common method that patients try. There are numerous magnifiers in addition to the hand-held types. Today, magnifiers come with stands, lights and in various sizes and strengths. If optical magnification is insufficient, then the use of computers with an attached camera may help. The cost of this technology is coming down and affordable. The low vision specialist will help to suggest the appropriate visual aids. The Talking Book Series and vocal scanners are other forms patients with ARMD use. The Canadian National Institute for the Blind (CNIB) is an excellent source from which to obtain these visual aids.
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