Macular degeneration affects cells in the macula, which is the part of the retina responsible for central and most acute vision. Central vision is essential for most basic tasks like reading, driving and recognizing people. Thus, although macular degeneration leaves peripheral vision un-impaired, it can be quite debilitating in its advanced state.
The disease exists in two forms, dry and wet.
Dry macular degeneration, the milder of the two forms, is by far the most common, accounting for roughly 90% of all cases. It is associated with the formation of small yellow deposits called drusen which accumulate under the macula. This phenomenon results in thinning and drying out of the macula, causing the macula to function poorly. Dry macular degeneration tends to develop gradually and usually does not result in major loss of central vision.
Wet macular degeneration is less common, but the vast majority of severe vision loss results from this form. In wet macular degeneration, abnormal blood vessels form underneath the surface of the macula. Leakage of blood and other fluids from these blood vessels causes the macula to lift up from its normally flat position, thus distorting and destroying central vision. Vision loss may be rapid and severe.
The primary cause of macular degeneration remains unknown. This condition typically occurs more frequently in individuals over the age of 60. Research has shown that other factors such as family history, cigarette smoking, and having abnormal cholesterol levels may contribute to the development of macular degeneration.
Macular degeneration symptoms may include:
Treatment for dry macular degeneration:
- Shadows, blurriness, or holes in the center of vision.
- Distorted vision, where straight lines may appear to be wavy
- Trouble seeing details both up close and at a distance.
- Difficulty telling colors apart, especially those close in hue.
- Difficulty adjusting to changes in light
Unfortunately, there is no treatment that can halt or reverse the dry form of macular degeneration, although dietary supplementation with antioxidant vitamins and zinc may help to slow the progression. Those at high risk should schedule a checkup with their ophthalmologist every one-to-two years to catch the disease in its infancy.
There is also no cure for wet macular degeneration. There are, however, several treatments designed to combat the disease. Early detection is very important because once vision is lost there is no treatment to regain it.
Treatments for wet macular degeneration:
- Anti-angiogenesis drugs — Known as anti-VEGF (anti-vascular endothelial growth factor) drugs, these medications inhibit proteins which contribute to abnormal blood vessel growth. Anti-VEGF medications have become quite popular in the treatment of wet macular degeneration in recent years due to their effectiveness in slowing down the disease process and reducing the likelihood of severe loss of vision. There are a variety of drugs that can be applicable for this purpose, some FDA approved, and some off-label (officially approved for a different application).
- Laser surgery — Certain types of wet macular degeneration can be treated with laser surgery, which uses a focused beam of light to slow or stop leaking blood vessels that can damage the macula. This treatment will sometimes halt the disease, thus saving the remaining vision of a patient. However, the laser leaves a scar, creating a permanent blind spot in the patient’s vision. The treatment is only applicable to a small segment of cases, in which some vision is sacrificed to save remaining vision.
- Photodynamic therapy — Photodynamic therapy uses a combination of a light-activated drug, which is injected intravenously and a cold laser treatment to slow or stop leaking blood vessels. This procedure leaves no scar and may be repeated several times as necessary.