Wet & Dry Macular Degeneration
Causes & Treatment of Macular Degeneration
Macular Degeneration is the most common cause of vision loss over age 70.
In my experience with the disease, un-recognized and un-treated Macular Degeneration is the most common reason someone gets a second opinion with me. Usually the patient is dis-satisfied with their vision after cataract surgery done somewhere else where the surgeon did not recognize the Macular Degeneration prior to the cataract surgery.
The macula is a small but important part of the retina that we use for our best reading, color and central vision.
Macular Degeneration can vary in severity but usually only the central vision is affected. Genetics, a lifelong diet that is poor in dark green leafy vegetables (and Lutein) , female sex and cigarette smoking all increase the risk of getting Macular Degeneration.
In fact smoking cigarettes increase the chances that a woman will get Macular Degeneration by 400%! Also, if she does get it, she is 400% more likely to get the more severe form of the disease.
In the early stages of the disease, the patient may not notice anything. 90% of the patients will have only mild vision loss. 10% will ultimately get severe vision loss. 1/2 of those will lose vision to a more aggressive form of the disease called Wet Macular Degeneration . Early treatment is geared toward avoiding severe vision loss and progression to Wet Macular Degeneration or to severe Dry Macular Degeneration.
Dry Macular Degeneration, results from atrophy of the retinal pigment epithelial layer below the retina, which causes vision loss through loss of photoreceptors (rods and cones) in the central part of the eye. There is a common misconception that there is no treatment is available for this condition. If fact, for patients with certain findings, a vitamin preparation with high doses of specific antioxidants where shown in a very large trial to reduce vision loss by 30%. It isn't for everyone with Dry Macular Degeneration though. In addition higher dose lutein and zeaxanthin have been suggested to slow the progression of dry macular degeneration and, in some patients, improve visual acuity. Perhaps 5% of those with Dry Macular Degeneration will progress to severe vision loss to a condition called Geographic Atrophy-a very severe form of Dry Macular Degeneration.
Wet Macular Degeneration, causes vision loss due to abnormal blood vessel growth in the choriocapillaris, through Bruch's membrane, ultimately leading to blood and protein leakage below the macula. Bleeding, leaking, and scarring from these blood vessels eventually cause irreversible damage to the retina and rapid vision loss ensues if left untreated. Usually, but not always, Wet Macular Degeneration results in patients with previous Dry Macular Degeneration.
Central Vision loss from Macular Degeneration is depicted by the drawing on the left.
The findings seen on exam early in the disease can help predict who is at risk for vision loss and help us prevent vision loss later.
Early on, there are small white dots called drusen that can be seen in the macula. They can come and go but are known to mildly increase the chance of future vision loss. For those patients, Dr. Mahootchi starts 20 mg of Lutein by mouth. Lutein is cheap --as little as $13 for a 5 month supply. We know that patients with poor lutein intake are at increased risk and the patients with Macular Degeneration have little lutein in their maculas. Lutein is necessary for normal macular function. There is currently a large clinical trial underway to study the effect of lutein. It takes at least 6 mg of lutein to get past the stomach and the process of digestion. That is why the 250 micro-grams found in most multi-vitamins hasn’t been shown to help. Dr. Mahootchi recommends 20mg of Lutein each day. It's the dose that is easily found in stores and online and is very cheap.
For those with large white fluffy drusen larger than a retinal vein (seen to the left), there is definite help backed up by the AREDS trial. Using the recommendations from the trial has been very successful in our practice. We have only 15 patients (October 2009) from the last 8 years who lost vision! Of those 1/2 lost less than one line of vision or were easily treated by Avastin Therapy. I over 50 patients who either quit or substituted or for some other reason stopped the AREDS vitamins (Preservision) and lost vision.
For those who do get Wet Macular Degeneration there are several new treatments available. They tend to work best when the patient gets to the doctor early in process--within a week or two of symptoms. Lucentis and Macugen both block new vessel growth and are expensive to the insurer or patient. Avastin works the same way and is much cheaper although not FDA approved for that purpose. It seems to work better. Avastin treatment is covered by Medicare. There is lots of good research on Avastin and it seems to be very safe. PDT (photodynamic therapy), intravitreal steroids, and Lasers are sometimes used but much less now that Avastin is available.
Managing Macular Degeneration is serious business. The information above is not meant to be a substitute for seeing a doctor trained to diagnose and treat Macular Degeneration.
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