Diseases / Macula degeneration

Understanding Macular Degeneration

Usually a condition that occurs only in older people, macular degeneration (commonly called AMD) is a progressive degeneration of the macula. The macula is located in the center of the retina, the nerve layer that lines the back of the eye. The retina senses light and creates impulses that are sent through the optic nerve to the brain.

The sensitive macula provides sight in the center of our field of vision. When we look directly at something, the macula allows us to see the fine details. This sharp, straight-ahead vision is necessary for driving, reading , recognizing faces, and doing close work, such as sewing.

As the population ages, AMD is becoming more common. There are 200,000 cases of AMD reported in the U.S. each year, and another 300,000 worldwide.
The two common types of macular degeneration are dry and wet. The dry form accounts for 90% of cases and is caused by aging and thinning of the tissues of the macula. It develops slowly and usually causes mild vision loss. People often notice a dimming of vision when they read.

Wet macular degeneration is a much greater threat to vision loss even though it accounts for only 10% of cases. With the wet form of the disease, new blood vessels grow beneath the retina where they leak fluid and blood and can create a large blind spot in the center of your visual field. If this happens, there will be a marked disturbance of vision.

There is a new and promising photodynamic treatment for the wet form of AMD. In this treatment, the patient is injected with a drug which collects in the blood vessels in the retina. Then a diode laser shines a red light at a precise waveleng that these vessels. This activates the drug to destroy the abnormal blood vessels.

Judith Lee