ARMD

Understanding Age-Related Macular Degeneration
The inside of the back wall of the eye is covered with a thin, transparent tissue comprised of multiple layers of neurons, or nerve cells. This layer, called the retina, is able to transform light energy into electrochemical energy, thereby changing it into the form that our nervous system uses to transmit information. The retina is very much analogous to the film in a camera. Light falls upon the film and changes the film chemically; presuming the light falling upon the film is well focused, a clear image should develop. But what happens if the film is of poor quality? No matter how clearly focused the incident light, a clear image can never be developed. The same is true for the retina. If the retina is unhealthy, it cannot create an accurate representation of even a well-focused image and therefore cannot send an accurate image to the brain. Although the retina covers two-thirds of the back wall of the eye, the portion of the retina that receives the focused light is actually about as large as the point of a pin! This region, called the fovea, lies within a somewhat larger area, about the diameter of a small pea, called the macula. This area has one of the highest metabolic rates in the entire body and receives one of the highest blood-flow rates in the body. This situation makes this area very susceptible to a number of problems. First, because metabolism is associated with waste products, this area must therefore produce and remove a very large amount of biochemical waste. In addition, this area is very sensitive to decreases in the quantity of blood flow or in the quality of that blood; if the blood is low in oxygen or food sources, this area will become weak. Finally, this area is very prone to poisoning because of its large blood flow and high metabolic rate. Age-related macular degeneration, or ARMD, is a disease caused by an apparent inability of the cells underlying and supporting the macula to remove the waste products made by the macula. This lifelong buildup of waste products leads to big problems!

Drusen, Choroidal Neovascularization and ARMD
The biological waste products that can accumulate in the macula are collectively referred to as drusen. Drusen seem to accumulate in the eye during the mature years, although there are conditions where drusen are seen in younger patients. Drusen are generally located beneath the retina, in a layer of cells called the retinal pigment epithelium, or RPE. The RPE backs the entire retina and serves as a crucial metabolic intermediary between the retina and the layer of blood vessels that feed the back side of the retina, the choroid. When drusen accumulate, they interfere with the functioning of the RPE, and this in turn interferes with the functioning of the outer layers of the retina. Drusen, which are often very hard, can abrade through the RPE. When this breach occurs, the choroid in that area sends new capillaries into the hole and under the retina. This condition is called choroidal neovascularization. The new vessels are not useful and not healthy. They leak blood into the space below the retina and prevent the retina from functioning. This accumulated blood can actually lift the retina up away from the RPE and further compromise the metabolic support of the retina. Age related macular degeneration (ARMD) is a condition where the drusen start to cause trouble. In its advanced stages, it can seriously decrease the fine vision permitting detailed viewing.

Laser Therapy
When age-related-macular-degeneration is associated with neovascularization, the retinologist, an ophthalmologist with advanced training in diagnosing and treating diseases of the retina, may be able to use laser therapy to destroy the abnormal new vessels. To determine this, the retinologist will take photographs of the back of a patient's eye while a small amount of a special vegetable-dye is coursing through the patient's bloodstream. This technique, called fluorescein angiography, will permit the retinologist to determine whether abnormal new vessels have been produced in the back of the eye, where they exist, and whether they would be susceptible to laser therapy. If they are treatable, then the doctor can perform the laser therapy in the office. No anesthesia is required and the patient may have his or her visual loss stabilized or perhaps even improved over a few weeks. As the patient ages, so does the retina, and so the patient and the retinologist must stay vigilant looking for new evidence of disease. The retinologist will usually give the patient a home-testing card, called an Amsler grid; this self-screening tool will allow the patient to determine whether new disease is occurring.

Nutritional Therapy
When age-related-macular-degeneration occurs without the presence of new abnormal blood vessels, the condition is called "dry ARMD". Although research to treat this degeneration is ongoing, no proven cures are available. However, there are still things an ophthalmologist can recommend that may slow the progression of the problem. Since smoking has been linked to ARMD, the cessation of smoking must be strongly urged. Second, tight control of systemic diseases such as hypertension and diabetes is advised. Third, appropriate nutrition including supplemental anti-oxidant vitamins and minerals, such as these found in Ocuvite Preservision or similar supplements may be beneficial. Lastly, there is evidence to suggest that the development and progression of ARMD in post-menopausal women may be slowed with hormone replacement therapy.