Sunday, January 15, 2006

macular degeneration (senile macular degeneration, disciform degeneration of the macula, Kuhnt Junius disease)

Macular degeneration is a major cause of visual disability in the elderly. It is the second-ranking cause of blindness and responsible for 12 percent of all blindness in the United States. Macular degeneration is the leading cause of blindness for people age 75 and over and is the most common cause of new cases of blindness among those who are age 65 and over. It is characterized by a loss of central vision, with a retention of peripheral vision. Senile macular degeneration is generally caused by poor blood circulation to the macular area of the retina. Age, smoking, ultraviolet light, nutrition, stress, hereditary factors, illness, and certain drugs are all suspected factors in the decreased blood circulation.
There is no medical treatment effective for most macular degeneration. It is important that macular degeneration is properly diagnosed through a variety of eye tests including fluorscein retinal angiography (visualization of retinal vessel after the injection of fluorscein). In a small number of cases laser treatment may be beneficial. The cases benefited by laser treatment are those in which there is an overgrowth of blood vessels. Early detection is critical in this instance.
Treatments with vitamins, hormones, low-fat diets, regular exercise programs, and systemic vasodilators (agents that cause dilation of blood vessels) have been proposed but controlled studies have not confirmed their effectiveness. Although it is not felt it will be of much benefit for reversing macular degeneration, these methods may be useful as preventive measures. Several recent reports suggest that 25-200 mg of zinc may be of value to stabilize macular degeneration. People with macular degeneration may be fitted with low-vision optical devices for reading. Stronger reading glasses, telescopic lenses, or high-intensity lights may also be helpful.
A person with macular degeneration will never go totally blind. Even if all central vision is lost the individual can continue many useful activities by relying on the side vision and the use of visual aids. Another common misconception is that the use of the eyes for reading and sewing will hasten the deterioration. Patients need to be told that this is not so and that there is nothing gained by "saving their eyes," although reading may be difficult. They will not "strain" their eyes and should plan to use their eyes as much as their diminished vision will allow them to do.
Less common is disciform degeneration of the macula (Kuhnt-Junius disease), which occurs in people over 40 years of age. The lesion is an extravasation (escaping from vessel into tissue) of blood between Bruch's membrane (innermost layer of choroid) and the pigment epithelium. There is no treatment at the present time.
Newell, F. W. Ophthalmology, Principles and Concepts, 7th ed. S1.Louis: C. V. Mosby Co., 1986.
Scheie, H. G. and Albert, D. M. Textbook of Ophthalmology, 10th ed. Philadelphia: W. B. Saunders, 1986.