Yellow protein deposits called drusen accumulate in the macula in the early stages. Advanced dry AMD occurrs when pockets of the retinal tissue have been destroyed.

Blood vessels leak causing bleeding and fluid accumulation under the retina

Age-related macular degeneration (AMD) is the most common cause of vision loss in individuals over the age of 50. The name of the condition derives from its cause: damage to the macula, the central zone of the retina, responsible for central vision.

The speed at which AMD advances is variable. For most patients, the condition progresses slowly and the changes in vision are imperceptible for some time. In others, the disease moves at an accelerated pace, leading relatively quickly to loss of central vision in one or both eyes.  Even in the advance stages, most patients retain their peripheral vision.

Stages and Types of AMD

There are three stages of AMD. These stages are designated both by signs detected by the ophthalmologist and symptoms experienced by the patient.

Early Stage AMD

During early AMD, the physician can diagnose the illness by the presence of more than the usual number of drusen, yellow deposits under the retina, These drusen of medium size. Typically, patients with early AMD are not yet experiencing any loss of vision.

Intermediate Stage AMD

When a patient is in the intermediate stage of AMD, the doctor observes large drusen. While some patients at this stage may experience small gaps in vision, most patients with intermediate AMD do not experience any significant vision loss.

Late Stage AMD

During late stage AMD, patients have enough damage to the macula to experience significant vision loss. The two types of late AMD are:

  • Dry, in which macula tissue is destroyed.
  • Wet, or neovascular, in which abnormal blood vessels grow, causing swelling and/or bleeding in the retina.

In the wet type of AMD, which progresses more rapidly than the dry, the newly developed blood vessels may leak blood and fluid. Visual loss in dry AMD usually occurs more gradually. Ninety percent of patients diagnosed with AMD have the dry variety, but approximately 10 percent of these patients later develop the wet variety of the disorder. Although patients with either type may experience vision loss, wet AMD progresses more rapidly.  Fortunately, wet AMD can often be effectively treated with caught early.

Treatment of AMD

Even though treatments often do not reverse the disease process, they are often able to slow the progression of symptoms so the patient can maintain as much vision as possible.  In the case of wet AMD, treatment with injections can often restore vision significantly if started early in the process.

Recommended treatments for AMD may include one or more of the following, each of which approaches controlling AMD in a somewhat different way:

  • Vitamin and mineral supplementation known as AREDS2 to slow down disease progression.
  • Injections of medication (anti-VEGF) for the wet AMD to reverse the bleeding and swelling in the retina.
  • Use of low vision aids