Macular degeneration is characterized by progressive deterioration of the center of the retina known as the macula. It is the leading cause of permanent vision loss in the United States affecting millions of people. The macula consists of the most sensitive nerve fibers in the back of the eye responsible for our central detail vision. It receives images and sends them to the brain via the optic nerve. Our maucla is critical for reading, recognizing faces, color vision, and seeing all other detail in the world around us. It is still unclear what causes macular degeneration. We know that genetics (family history), diets low in vitamins and omega-3 fatty acids, and smoking contribute significantly to the risk of developing macular degeneration. Fortunately, through research, we are beginning to understand how to better treat this disease.
Types of Macular Degeneration
There are two types of macular degeneration: dry and wet. Dry macular degeneration is characterized by the accumulation of tiny clumps of scar tissue under the macula called drusen. When enough drusen accumulate, dry macular degeneration is diagnosed. A second rarer form of dry macular degeneration exists known as geographic atrophy. This occurs when the retinal pigment (RPE) epithelial layer under the retina degenerates with time. The RPE is critical for the proper functioning of the macula. As the RPE deteriorates so does the central vision.
Wet or exudative macular degeneration is characterized by the growth and leakage of abnormal new blood vessels under the macula. These blood vessels spontaneously bleed and leak fluid causing the macula to blister. Vision loss is severe and rapid. Almost all people with wet macular degeneration start with the dry form and only 10% with the dry form go on to develop wet macular degeneration. Discovered recently has been the fact that the abnormal blood vessels grow initially due to the overproduction in the macula of a naturally made substance called vascular endothelial growth factor (VEGF). Why the overproduction occurs is unknown. All current treatment today is aimed at stopping the deleterious effects VEGF has on the vision of people with wet macular degeneration.
What Causes Macular Degeneration?
The actual cause of both forms of macular degeneration remains a mystery. Genetics, family history, diets poor in vitamins and omega 3 fatty acids, and smoking significantly elevate the risk of developing macular degeneration. It tends to be more common in women, fair-skinned people, and in people with light-colored eyes. The absence of these risk factors, however, does not rule out the possibility of macular degeneration.
What Are The Symptoms of Macular Degeneration?
The symptoms of macular degeneration vary greatly. Symptoms may range from nothing to severe central vision loss. Blurriness and distorted vision (straight lines appearing wavy) are frequent symptoms which patients often mistakenly attribute to cataracts or a need for new glasses. Very often, people unknowingly have dry macular degeneration and learn only of its presence after accidentally discovering (sometimes months after) loss of central vision in one eye. This finding prompts an emergent visit to the doctor and only then are people diagnosed and made aware of their condition and risk of vision loss. Dry macular degeneration usually affects both eyes, but wet can occur only in one eye. It is important to realize that the macula is in the back of the eye and has no pain fibers, so macular degeneration is never the cause of redness, irritation, or pain.
How is Macular Degeneration Diagnosed?
A complete eye exam by an ophthalmologist is needed to diagnose macular degeneration. Office tests while the pupils are dilated will allow your doctor to determine whether you suffer from macular degeneration. Often OCT and flourescein angiograms will be used to confirm the diagnosis and understand the extent of severity.
How is Macular Degeneration Treated?
Dry macular degeneration
While there is no cure for macular degeneration, a special formula of vitamins, called the AREDS formula (age related eye disease study) has been shown to slow the progression of dry macular degeneration. There is a high level of vitamin A in these vitamins and those patients who continue to smoke are at higher risk of developing lung cancer while on AREDS vitamins. Other vitamins are available for those who smoke. Please ask your physician before starting vitamin therapy.
At Medeye Associates, our research department is actively looking at new and exciting therapies for the treatment of dry macular degeneration. Please call us today to schedule an exam and ask about our clinical trials.
Wet macular degeneration
Treatment for wet macular degeneration has made great advances in the last decade. Intravitreal injections are used to counteract the overproduction of VEGF and eliminate the fluid accumulation under the macula. If caught early enough, vision can be restored to a large degree. However, for those who have developed scarring under the macula may not benefit them as much. This is why it is critical for people to be examined regularly and educated as to their risks for developing macular degeneration. Patient education is a powerful weapon against vision loss from macular degeneration.
At Medeye Associates, our research department is actively looking at new and exciting therapies for the treatment of wet macular degeneration. Please call us today to schedule an exam.