Dear Dr. Gott: My 31-year-old son has retinitis pigmentosa. His sight has been decreasing little by little. We know it is an incurable disease. Has science made any inroads into this field? Is there is a place in the United States or Europe where they are doing any trials? Do you have any suggestions, other than vitamin A, on how to prolong his vision?

Reply: Retinitis pigmentosa is an eye disease that causes damage to the retina, a nervous-tissue membrane that receives images of outer objects, carrying signals to the brain via the optic nerve. This relatively uncommon condition can be caused by numerous genetic defects and tends to run in families.

In fact, the Ocular Molecular Genetics Institute's seminar at Harvard Medical School has recognized more than 45 genes for this condition. These genes account for about 60 percent of all patients, with the remaining 40 percent unidentified at this time. It affects about one in every 4,000 people in the United States.

Common symptoms most often appear during childhood; however, severe visual difficulties develop in early adulthood. They include diminished vision apparent at night or in darkness. As the disease progresses, loss of peripheral vision will follow.

Advanced cases will progress to a loss of central vision. Cataracts are common at an early age. The condition may lead to partial blindness, but complete loss of sight is uncommon.

Research is ongoing for microchip implants placed inside the retina during the early stages of the disease. Nutritional intervention, to include vitamin A palmitate, an antioxidant and fish rich in omega-3 oil, appears to slow the progression of the disease in many patients.

With this in mind, Harvard or a similar large medical school might be a good starting place to determine whether your son can enter a programme. Speak with your son's primary-care physician to determine the best source for your needs.

Dear Dr. Gott: I am a 75-year-old female and had pain under my left breast. I had lots of tests, bought expensive bras and had X-rays, all without relief of my pain. I went to a chiropractor to have my lower back adjusted. When I mentioned the pain, he indicated the back is out just opposite where the pain occurs. He adjusted it, and within minutes, the pain was gone. What a relief! When it gets to bothering me, I go back to the chiropractor.

Reply: I commend your chiropractor. If you presented in my office with your complaint, I must admit I probably would not have started with the back as a cause. After listening to what initiated the pain, I might have recommended a trial of an over-the-counter medication such as ibuprofen, the use of a heating pad, or a topical cream.

Without question, I would determine the date of your last mammogram and order one if the timing were right. I then might recommend a visit to a pulmonologist to determine the status of your lungs and the surrounding muscles. You found the answer to your problem. Congratulations!

To give you related information, I am sending you a copy of my Health Report "Breast Cancer and Disorders''. Other readers who would like a copy should send a self-addressed, stamped, number 10 envelope and $2 to Newsletter, PO Box 167, Wickliffe, Ohio 44092. Be sure to mention the title.

Dr. Gott is a retired physician and the author of 'Dr. Gott's No Flour, No Sugar Diet' and 'Dr. Gott's No Flour, No Sugar Cookbook'. Contact him c/o United Media, 200 Madison Avenue, fourth floor, New York, New York 10016.