Macular degeneration is a group of disorders which cause deterioration in the central part of the retina called the macula. The most common type of macular degeneration is age-related macular degeneration. Other types of macular degeneration (such as hereditary, myopic, inflammatory, and toxic) exist, but are much less common. The following comments are limited to age-related macular degeneration.

There are two main types of macular degeneration – dry (non-exudative) and wet (exudative). The dry type of macular degeneration is characterized by drusen and atrophy, which can be thought of as age spots on the retina. The dry type of macular degeneration is the most common type, accounting for 90% of cases. The other type of macular degeneration is the wet variety. It is called wet because there is leakage from abnormal blood vessels under the retina, resulting in macular swelling or macular bleeding. Although the wet type is less common, it is more likely to cause a serious disturbance in a patient's vision.

The only symptoms of macular degeneration are visual symptoms. Pain, tearing, red eyes, etc., are NOT associated with macular degeneration. Some patients with macular degeneration are unaware of any visual symptoms – either because their macular degeneration is too mild or because with both eyes open, the good eye “takes over” and the involved eye is “ignored” by the brain. Therefore, checking the sight one eye at a time (by covering each eye sequentially) is a more sensitive way to check for symptoms. Patients with dry macular degeneration may have no symptoms, even when checking each eye separately. However, as dry macular degeneration progresses, the vision may become less clear. Patients with wet macular degeneration notice distortion (bending of straight lines, such as telephone poles, door frames, and Venetian blinds), washed-out or bleached-out colors, perception that print is smaller with the involved eye, or blind spots in the central vision. The symptoms may depend on the level of severity and may not be noticeable unless they are intentionally looked for. These symptoms are best noticed when checking each eye separately (by blocking the opposite eye) and comparing the quality of sight between the two eyes.

The cause of macular degeneration is not known. The process of sight is complex and places a lot of demands on the retinal tissue in the macula. As the macula ages, it is less able to keep up with the stresses placed upon it, making it more susceptible to macular degeneration. We believe there are multiple risk factors for developing macular degeneration, but not a single cause. Macular degeneration runs worse in some families, so there is probably a genetic component or predisposition. Additionally, there are risk factors for macular degeneration, such as smoking, diet, nutritional status, sunlight exposure, eye color, and others. At the present time, researchers have not been able to pinpoint a single cause for macular degeneration, nor do we know why some people get the dry form of macular degeneration and others get the wet form. There are ongoing studies which may provide more information in coming years.

Patients with the dry type of macular degeneration do not notice a change in vision from one month to the next. However, the vision can gradually deteriorate over years. Few people with dry macular degeneration will develop enough visual loss to be considered “legally blind.” At the very worse, dry macular degeneration causes loss of central vision, but the peripheral vision is spared. The wet type of macular degeneration progresses more rapidly. If left untreated, it will usually cause noticeable loss of vision from one month to the next. Although the wet type of macular degeneration accounts for only 10% of macular degeneration, it causes 90% of the severe visual loss associated with macular degeneration. Wet macular degeneration, at its worse, causes a central blind spot, but spares the peripheral vision. Treatment, when appropriate, can reduce the risk of visual loss from macular degeneration.

Macular degeneration is diagnosed by performing a complete eye examination. Optimally, the exam should include dilation of the pupils with drops. Most people can be diagnosed with the standard equipment in the eye doctor's office. Other testing, including retinal photography, and/or retinal angiography and/or OCT scan, may be necessary to adequately assess the macula and to determine eligibility for treatment. Patients need to test the vision of their own eyes (checking each eye separately) looking for blind spots, progressive symptoms, or distortion. Your eye doctor can give you further details on how this can be done most effectively.

The treatment options for macular degeneration continue to evolve. This complicated subject needs to be discussed with your eye doctor. Recently a study reported that a specific combination of vitamins and minerals can slow the progression of macular degeneration. People who eat lots of leafy vegetables, do not smoke, and have not needed treatment for high blood pressure, have a more favorable course. These issues are currently under study and more information should be forthcoming. Treatment for wet macular degeneration has expanded recently. Intravitreal injections of medicines have become the mainstay of treatment for wet macular degeneration. Laser treatment, when appropriately applied, reduces the risk of visual loss and improves the likelihood of retaining vision. The eligibility for laser treatment and the type of laser to be used vary according to the findings present on examination and angiography. Other treatment options for wet macular degeneration, including retinal surgery, radiation, and ocular photodynamic therapy, are still under study.