Adapted from an article by Tom Hogland - Science Information Manager for The American Foundation Fighting Blindness.

Nutrition
Some studies have suggested a link between minerals, vitamins and anti-oxidants in the diet and the occurrence of AMD. The American national Eye Institute is conducting a large scale clinical trial on 4700 older age adults to determine whether anti-oxidant substances (Betacarotene, Vitamins C and E) and the minerals Selenium and Zinc either reduce the risk of developing AMD or slow the progression of the condition. Results will be available in the year 2000. Another group of nutrients, Carotenoids, and in particular, Lutein and Zeaxanthin, are also being studied. These are found in the macula giving it its characteristic yellow colour. They are found in high concentrations in spinach, kale, broccoli, peas, brussels sprouts and lettuce. It has been suggested that these Carotenoids may protect the macula from damage by ultra violet light. While this is as yet unproved, it makes sense for all people with retinal degeneration to protect their eyes against high levels of UV by wearing brown lensed or treated sunglasses which block out the UV light.

Retinal Cell Transplantation
Research suggests that transplants of RPE, the nurse layer of cells which support the photoreceptors, may halt or slow further vision loss. Patients undergoing this experimental technique develop immune response to the donor RPE cells. New methods to control this rejection are now being studied.

Photodynamic Therapy
In order to minimise laser damage to surrounding cells in the treatment of wet AMD, a laser sensitive dye is being used in conjunction with low intensity lasers. The laser sensitive dye is activated by the laser and destroys the leaky blood vessels without damaging the surrounding healthy tissue. Preliminary results from an American clinical trial are very encouraging.

Radiation Therapy
Radiation is well known for the treatment of cancer by attacking new cell growth. Small studies to evaluate the effect of low dose radiation on new blood vessel growth in Wet AMD have shown promise. Three large scale trials are currently underway to confirm these findings and results are expected in the coming year.

Survival Factors
Axokine - the survival factor which may halt or slow retinal degeneration is currently being tested in a clinical trial on RP patients. Researchers think that Axokine may also be beneficial to patients with AMD. "Although no magic bullet to stop or cure this sight stealing disease has yet been found, basic studies and human clinical trials are rapidly progressing. Through this effort we are confident that significant progress will be made in the not too distant future". Editor's note: Tom Hoglund is one of the retinal experts who responds to scientific questions on the RP internet list (see address below). Tom has the knack of explaining highly technical scientific information in easy to understand layman's language.