Macular Degeneration
As adults age, cells throughout the body begin functioning at less than 100%. Sub-optimal cell performance over time is how and why we age. It’s a natural process. The cells in our eyes are no exception.
Macular refers to the macula, the center of the retina, where the finest details of visual images occur. When macula cells degenerate, a substance called drusen forms. When drusen deposits appear beneath the retina, vision loss, distinguished by blurred and distorted images as well as the appearance of small dark areas in the visual field, occurs. The severity of this vision loss is wide-ranging.Macular degeneration’s effect on some people is minimal. It can be more significant upon others, blurred or distorted images in the center of the visual field allowing only peripheral vision. Blindness is a rarity.
The gradual decline of sharp, clear images on the macula is referred to as Age-Related Macular Degeneration (AMD).Onset of AMD usually occurs near the age of 60. Other onset predictors include cigarette smoking, obesity and hypertension (elevated blood pressure). The most significant predictor of macular degeneration is a family history.
There is a severe form of rapid onset macular degeneration referred to as “wet macular degeneration”. Macula cells rapidly and severely deteriorate as a result of hemorrhaging vessels behind the retina. Leakage of blood and fluid from these fragile, weakened vessels causes vision loss much faster than the gradual decline associated with aging. Wet macular degeneration, also known as neovascular macular degeneration, occurs in about 10% of macular patients.
To diagnose macular degeneration, an ophthalmologist uses an ophthalmoscope (an instrument designed to give a magnified view of the retina) to look at the macula. Drops are placed in the eye to dilate the pupil to facilitate the retina examination. If the ophthalmologist believes wet macular degeneration is occurring, a tomography scan is performed to study different layers of the cells of the macula. Dye is injected into the patient’s circulatory system through their arm. When the dye reaches the retina, the ophthalmologist can see hemorrhaging or abnormal vessels inside the retina as well as determine the severity of the degeneration.
Treatment of wet macular degeneration focuses on inhibiting or cauterizing hemorrhaging vessels under the retina. This is done with medication or laser surgery or both.
Ophthalmic drug research has developed medications that inhibit the growth of abnormally fragile retinal blood vessels that hemorrhage under the retina. These medications (anti-VEGF) are injected directly into the eye in a painless, out-patient procedure. Vision improves in many patients when the hemorrhages resolve. Multiple injections may be administered over many months to ensure continued reduction in the growth of abnormal vessels, halt vision loss and, in some cases, restore previously lost vision.
Another drug treatment is photodynamic therapy (PDT). A light sensitive chemical is injected into a vein in the patient’s arm. When it reaches the retina, a laser beam targets only the abnormal blood vessels in the macula, activating the drug that destroys them.
A third treatment for wet macular degeneration is direct laser cauterization. Leaking blood vessels under the retina are targeted and destroyed using a high energy, precise beam of laser light.
Because there are no medications or surgical techniques to correct or stop the gradual degeneration of macula cells, a variety of optical devices have been designed to improve the vision of Age-Related Macular Degeneration patients. Reading and driving are now possible for some macular degeneration patients. Additionally, clinical studies have shown a special formulation of vitamins A (beta carotene), C, E and zinc can significantly delay and, in some cases, prevent continued deterioration of the macula.
There is no evidence, however, that this formulation prevents macular degeneration from occurring in people who have no symptoms. On-going clinical studies are identifying specific dietary and life style behaviors that can reduce the risk of vision loss associated with macular degeneration. At this time, the most promising dietary preventatives include dark leafy greens, colorful fruits and vegetables high in lutein and zeaxanthin. The lifestyle behaviors include weight and blood pressure control and smoking. Promising supplements for women include folic acid, B6 and B12. Fish oil and lutein for men and women.
We can’t modify our age or our genetics but we can initiate and modify our diet and lifestyle.
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