Metformin (available under trade names such as Glucophage, Glumetza, and Fortamet) may also reduce the risk of age-related macular degeneration (AMD), a significant cause of visual loss in persons aged 50 and older, according to new study. The researchers noted that although more studies are needed to confirm these findings, the data so far suggest that patients using metformin should be informed about the potential reduction in their risk of developing AMD. AMD is the most common form of blindness in people older than 75. It's estimated to affect millions of people worldwide. About half of those who get AMD suffer serious consequences such as blindness. The other half have less severe symptoms that do not interfere with their daily lives but which can include blurry vision or blind spots in their field of view. People who take insulin or hypoglycemic drugs such as sulfonylureas or meglitinides are at increased risk of developing vision problems because these medications increase blood glucose levels. As high blood glucose levels contribute to the development of several complications, including nephropathy (a disease of the kidneys), neuropathy (nerve damage), and retinopathy (eye damage), patients taking these medications should be made aware of the risk. In recent years, researchers have begun to investigate the relationship between diabetes and AMD.