A recent study has shown that metformin, a common drug for treating diabetes, slows the progression of age-related macular degeneration (AMD), the most common cause of blindness in Western countries.
The study found that people with diabetes over the age of 55 who were taking metformin were 37% less likely to develop intermediate-stage macular degeneration over five years compared to those who did not use the drug.
Age-related macular degeneration (AMD) is a disease that affects the central retina (the macula) at the back of the eye, leading to damage or death of the light-sensitive tissue. It presents in two main forms: dry AMD and wet AMD, the latter resulting from abnormal blood vessel growth. Moderate to advanced AMD affects approximately 10-15% of people over 65, equivalent to about 1.1 to 1.8 million people in the UK, making it the leading cause of blindness in high-income countries.
The study used eye images of 2,000 people who participated in a routine eye examination program for diabetic patients in Liverpool over a five-year period. Researchers assessed the presence and severity of macular degeneration in the images, then compared those taking metformin with those not taking it, adjusting the results for age, sex, and duration of diabetes.
The results showed that the five-year probability of developing intermediate macular degeneration was 0.63 among metformin users compared to the group not using the drug.
Dr. Nick Beer, the ophthalmologist who led the study, said: "Most people with age-related macular degeneration do not receive any treatment, so this is a major breakthrough. What we need now is to test metformin as a treatment in a clinical trial, because it has the potential to save the sight of many people."
The results were published in the journal BMJ Open Ophthalmology.
