Macular Degeneration & Disease
The macula is the most central portion of the retina, directly opposite the lens. It is where the greatest number of light-sensitive cells, called cones, are located. Cones allow us to see color and fine detail. The high concentration of cones in the macula gives people extremely detailed and rich central vision. When the light sensing cells (cones) in the macula (the most central portion of the retina) gradually stop working and eventually die, it is called macular degeneration.
You will not go stone blind from this disease. As you may already recognize, it can make more difficult or impossible a number of things in life, including reading and driving a car. It can make television viewing more difficult and less satisfying. However, age-related macular degeneration leaves the peripheral (side) vision intact. With this vision there is no need to fear descending into darkness, tripping over furniture, running into walls or needing to carry a white cane. Most patients, even with severe age-related macular degeneration, are still able to live on their own.
There is no evidence that visual effort damages the retina. There is no reason to stop reading and watching television to save the eyes. If the macular degeneration is going to progress, it will progress on its own, not on account of something you do.
Macular degeneration comes in two overlapping subtypes, dry and wet. Wet involves exudation of fluid under the macula (the center of the retina) and usually involves the growth of abnormal new blood vessels. Wet usually results in a much more rapid loss of visual clarity, often measured in weeks or months; dry progresses much more slowly. Unfortunately, dry degeneration can evolve into wet.
In the case of "wet" macular degeneration, it is sometimes possible to treat the problem in its early stages with laser surgery. The highly focused beam of light seals the leaking blood vessels that damage the macula. This procedure can slow the rate of vision loss, but cannot halt macular degeneration. Laser surgery also leaves a small, permanently dark "blind spot" at the point of each laser contact. Overall, the procedure can preserve more sight than it damages.
Wet Macular Degeneration And Its Treatment
Symptoms of distortion in the central vision (for example, lines that should be straight appearing curved) are sometimes a sign of new blood vessel disease that may be treatable. Typically, this type of change develops over a period of a few weeks. If distortion changes of this type develop you should call and arrange an appointment for an evaluation.
Despite all the wonders of medical science, we have limited treatment options for dealing with wet macular degeneration.
Conventional heat laser treatment may be offered when a small plaque of new blood vessels grows into the space under the retina where it does not belong. Such new blood vessels can be usefully treated only when they do not underlie the center of the macula. Even when heat laser treatment can be offered, there is a 50% recurrence rate over the following three years. The retina above the lasered blood vessels is also burnt in the treatment, inevitably leaving a blank spot in the vision corresponding to the treated area.
Ocular photodynamic therapy (OPT), available since about 2000, is used to treat some specific types of new blood vessels that have grown in under the center of the retina. OPT involves the infusion of a special dye (Visudyne) into a vein followed by an 83-second exposure to a low-intensity laser light. The treatment is repeated every three months for an average of five cycles in two years. After the infusion, the patient must stay out of the sun for at least 48 hours. Sadly, although these treatments have been proven to be better than observation, in the long run, the final vision is usually worse than the starting vision.
OPT + Intraocular Steroid Injection, commonly used since mid-2004, seems to offer a better chance than OPT alone of improving vision at least for some time. With steroid, there also seems to be a chance of skipping the second and maybe the third OPT treatment. However, steroid injection is a two-edged sword. There is between a one in one hundred and one in one thousand chance of infection, which can be a disaster, and about a 3 or 4 in 10 chance of a rise in pressure (steroid glaucoma). Most of this glaucoma can be treated successfully with eye drops (sometimes expensive) applied for several months. There is also an increased risk of cataract. Even so, this combination sometimes may offer the best balance of reward versus risk, nuisance, and expense.
Macugen, available here since February 2005, is injected into the eye every six weeks for one to two years. It often requires two or three injections to suppress blood vessel growth and leakage, and often vision worsens some before it stabilizes. There is a separate brochure available concerning this treatment. It is FDA approved and covered by most insurance carriers.
Avastin (see its own information and consent form) is also injected. It is often, but not always, dramatically effective in suppressing vessel growth and leakage, but, since it has not been as extensively studied as Macugen and Lucentis (the use of Avastin is "off-label") we aren't quite as sure of its long-term ocular and whole body safety. Like Macugen and Lucentis, Avastin is a suppressant and not a cure. In most cases, an injection every 6-10 weeks is necessary to keep the disease in check. Avastin seems to last a little longer in the eye than does Lucentis and therefore may require slightly less frequent injections. It is also much cheaper at about $75 a dose, compared to almost $2000 per dose for Lucentis. (In both cases, at least for the treatment of macular degeneration, most of the drug cost should be covered by primary insurance and a supplement.)
Lucentis, another injectable drug closely related to Avastin and Macugen, was approved by the FDA for treatment of wet macular degeneration in August of 2006. It appears equally dramatically effective as Avastin and, so far, appears to be quite safe over several years of use. Current testing suggests an injection every month, but as we gain more experience we may try to stretch that to every two months.
Other Combination Treatments, e.g. OPT plus Avastin or Lucentis +/-steroid, may one day prove to be the most effective and durable, but, so far, all combinations are based on educated speculation.
Diet, Lifestyle, And Macular Degeneration
1. Eat Your Vegetables (like your mother told you!) and fruits.
Seddon, et al, compared dietary histories over the last year's recalled food intake between a group of over four hundred 55 to 80-year-old patients with wet (severe) macular degeneration and over four hundred matched patients without macular degeneration. They found that there was a steady decrease in relative risk with greater intake of dark green, leafy vegetables (specifically spinach and collard greens, and, by reasonable extension, kale, mustard, dandelion, and turnip greens). The risk of severe macular degeneration was less than half among those who recalled eating five or more helpings of such foods per week compared to those who ate less than one helping per month.
Dark leafy green vegetables contain more lutein and zeaxanthin than other vegetables. Some have concluded that lutein and zeaxanthin are the part of dark leafy green vegetables that cause the protective effect against macular degeneration. However, this has not been scientifically tested in humans. Lutein and zeaxanthin are carotenoid chemicals related to vitamin A and beta-carotene. It seems to us that the better bet is to consume the vegetables themselves, since some other chemical in them may be the important one. (This is unless you are taking Coumadin and cannot eat such vegetables because of their Vitamin K content.)
Note: This study clearly demonstrates a very interesting relationship, but it does not establish cause and effect. We could see the same relationship if, for example, there were a gene that caused macular degeneration in later life that also caused people to think that spinach tasted awful. Furthermore, dietary habits recalled for the last year may not represent dietary habits of a lifetime. So even if there is cause and effect relationship, it may or it may not make a real difference if one changes one's dietary habits later in life.
2. Quit Smoking.
Many studies have established a relationship between smoking, even in small amounts, and macular degeneration. Furthermore, smoking increases your risk of lung cancer if you take the supplements discussed below.
3. Lose weight and exercise
Both are associated with a lower risk of macular degeneration.
4. Eat some fish and nuts
Occasional (once a week) consumption of some oily fish (salmon, tuna, or mackerel, for example) and/or some nuts is associated with a lower risk of macular degeneration. This points to a possible relationship between decreased risk and omega-3 and omega-6 fatty acids.
Vitamin And Mineral Supplements For Macular Degeneration, The Age-Related Eye Disease Study (AREDS)
The long-awaited results of the Age-Related Eye Disease Study (AREDS) were published in the October 2001 issue of Archives of Ophthalmology. The study clearly demonstrates that certain vitamins and minerals taken on a daily basis at relatively high dosages produce a roughly 30 percent reduction in the risk of progression of macular degeneration and visual loss compared to placebo. These results held for eyes demonstrating at least intermediate-sized drusen at entrance into the study. Patient's eyes were observed for between five and seven years. Eyes with less than intermediate-sized drusen showed so little progression in both groups that no benefit was detectable. The daily dosage of the vitamins and minerals used in the study are as follows:
- Vitamin C 500 mg
- Vitamin E 400 IU
- Vitamin A (as beta carotene 15 mg) 28,640 IU
- Zinc 69.6 mg
- Copper 1.6 mg
This combination of vitamins and minerals is contained in PreserVision Soft Gels and Ocuvite PreserVision made by Bausch and Lomb. (There are some other preparations on the market that contain the same doses. They are identified as being "AREDS" preparations.)
"PreserVision AREDS Soft Gels." These are smaller and easier to swallow than the tablets (Ocuvite PreserVision), and you only need one with breakfast and one with supper. They are usually available at Costco. Either PreserVision Soft Gels or Ocuvite PreserVision should not cost more than $14-15 per month.
Take one tablet with breakfast and one tablet with supper. (For Ocuvite PreserVision that's two and two.) Plain Ocuvite, Ocuvite with Lutein, I-Vite, and I-Caps do not achieve the study dosages (I-Caps AREDS Formula does, however). Both PreserVisions are nonprescription items. They both carry a blue label. Look for the word "PreserVision."
- If you smoke, do not take beta-carotene. Instead, we recommend PreserVision Lutein Soft Gels. If you can't find them locally you may want to order from www.bausch.com. Used at the levels in this study beta-carotene has been demonstrated elsewhere to increase the likelihood of the development of lung cancer in smokers. On the other hand, if you're a smoker and concerned about lung cancer, quitting smoking is 80 times more effective than not taking beta-carotene in decreasing your risk!
- If (unlikely) there is any chance of you becoming pregnant, discontinue beta-carotene.
- Besides Centrum (used by about 60 percent of the people in the study) or Centrum Silver, do not take other vitamin and mineral supplements that add more than a token amount to the dosages of the AREDS vitamins and minerals.
- Note: Beta-carotene is a precursor of Vitamin A. Do not add additional Vitamin A to this beta carotene dose.
- At your next appointment, do tell your internist you are taking these vitamins and minerals, how much you are taking, and why you are taking them. Bring in the bottle!
Things We Do Not Know
- Whether the arguable risks of these supplements outweigh the benefits among patients with a family history of macular degeneration or with less than intermediate sized drusen.
- Whether this supplementation has any value for patients who have already lost significant central vision in both eyes as a result of neovascular (wet) macular degeneration.
- Whether there are long-term risks to supplementation, like those we know about smoking and beta-carotene. Other possible problems have not been systematically evaluated in studies longer than five to seven years.
The Lilac Low Vision Center in Spokane at N 1212 Howard (telephone 509-328-9116) can often help patients work out some of the difficulties encountered when central vision diminishes, for example, showing a way to set up one's oven so that the temperature can be read. They also have a wide selection of optical aids to try. It is usually best to bring the particular kind of material that you most want (and think you might realistically be able) to work with at the time you visit them. They and we at the Spokane Eye Clinic have examples of electronic magnifiers that many patients have been able to use to accomplish tasks like balancing their checkbook. Unfortunately, closed-circuit television is still relatively expensive, a minimum of $800.00.