Macular Degeneration
The leading cause of Vision Loss

“DRY’ Macular Degeneration

Causes

No one knows exactly what causes dry macular degeneration. But research indicates it may be related to a combination of heredity and environmental factors, including smoking and diet.

Risk factors

Factors that may increase your risk of macular degeneration include:

• Age. This disease is most common in people over 50.
• Family history and genetics. This disease has a hereditary component. Researchers have identified several genes that are related to developing the condition.
• Race. Macular degeneration is more common in Caucasians.
• Smoking. Smoking cigarettes or being regularly exposed to smoke significantly increases your risk of macular degeneration.
• Obesity. Research indicates that being obese may increase your chance that early or intermediate macular degeneration will progress to the more severe form of the disease.
• Cardiovascular disease. If you have had diseases that affected your heart and blood vessels, you may be at higher risk of macular degeneration.

Symptoms

Dry macular degeneration symptoms usually develop gradually and without pain. They may include:

• Visual distortions, such as straight lines seeming bent
• Reduced central vision in one or both eyes
• The need for brighter light when reading or doing close work
• Increased difficulty adapting to low light levels, such as when entering a dimly lit restaurant
• Increased blurriness of printed words
• Decreased intensity or brightness of colors
• Difficulty recognizing faces

“Wet” Macular Degeneration

Approximately 10-15% of the cases of macular degeneration are the “wet” (exudative) type.

Causes

With the “wet” type of macular degeneration, abnormal blood vessels (known as choroidal neovascularization) grow beneath the retina and macula. These new vessels may then bleed and leak fluid, causing the macula to bulge or lift up from its normally flat position, thus distorting or destroying central vision. Under these circumstances, vision loss may be rapid and severe.

Patients may see a dark spot (or spots) in the center of their vision caused by the blood or fluid under the retina. Straight lines may look wavy because the macula is no longer flat and smooth. Peripheral vision is rarely affected. Some patients do not notice changes, despite the onset of neovascularization. Therefore, periodic eye examinations are still very important for patients at risk.

Treatment

Treatments are available that may help slow disease progression, preserve existing vision and, if started early enough, recover some lost vision.

Laser

Until recently the only available treatment to seal leaking blood vessels associated with wet AMD was with a laser. The existing laser therapies are limited in their effectiveness and may also lead to scarring of the macula and additional vision loss.

Photodynamic therapy

During photodynamic therapy, your doctor injects a drug called verteporfin (Visudyne) into a vein in your arm, which travels to the blood vessels in your eye. The doctor then shines the light from a special laser onto the abnormal blood vessels in your eye. This activates the drug, causing the abnormal blood vessels to close, which stops the leakage.

Photodynamic therapy may improve your vision and reduce the rate of vision loss, though you may need repeated treatments, as the blood vessels may reopen.

Anti-VEGF

Currently, the most common and effective treatment for wet Macular Degeneration is anti-VEGF therapy. VEGF is an acronym for vascular endothelial growth factor. It is a signal protein produced by cells that stimulates the formation of blood vessels. Which is what wet Macular Degeneration invovles (the formation of blood vessels). Therefore, an intraocular injection of an anti-VEGF inhibits the formation of new blood vessels behind the retina and may keep the retina free of leakage.

Researchers report high rates of success with anti-VEGF injections, including receding blood vessels beneath the retina, a far slower progression of the disease, and, in some cases, moderate gains have been made in vision.