Evaluation of Oral Minocycline in the Treatment of Geographic Atrophy Associated With Age-Related Macular Degeneration

Background: Age-related macular degeneration (AMD) is the main reason older people lose their vision. It affects the macula, the center of the retina needed for sharp, clear vision. Researchers want to see if an antibiotic can help people with an advanced form of AMD, Geographic Atrophy (GA). Objective: To see if minocycline is safe for people with GA and if it helps preserve their vision. Eligibility: People age 55 and older who have GA in at least one eye. Design: Participants will be screened with physical exam, medical history, blood tests, and eye exam. Participants will take minocycline. They will take 1 pill twice a day for at least 3 years. Participants will have a minimum of 11 study visits. (But they are not every 3 months.). At each visit, participants will have a medical history. They may have: Blood tests. Eye exam. Vision, eye pressure, and eye movements will be checked. The pupils may be dilated. The inside of the eyes may be photographed. Their thyroid gland felt while they swallow. Microperimetry. They will sit in front of a computer and press a button when they see a light on the screen. Fluorescein angiography. An intravenous line (IV) will be placed in an arm vein. A dye called fluorescein will be placed in the IV and travel through the veins to the blood vessels in the eyes. A camera will take pictures of the dye as it flows through the eye blood vessels.