- Researchers say the type 2 diabetes medication metformin may help manage age-related macular degeneration.
- They said people taking metformin were 37% less likely to develop the intermediate stage of the chronic eye condition, which may lead to vision loss and blindness.
- Experts say more studies are needed to confirm the association and that metformin should not yet be prescribed for treating age-related macular degeneration.
A commonly prescribed medication to treat type 2 diabetes may also help older adults with age-related macular degeneration, according to a new study.
Researchers said people with diabetes ages 50 and older who were taking metformin were 37% less likely to develop the intermediate stage of age-related macular degeneration (AMD), which can lead to vision loss and blindness.
The findings were published on February 2 in BMJ Open Ophthalmology.
Scientists from the University of Liverpool in the United Kingdom analyzed photos taken of the eyes of 2,000 people who were part of a routine diabetic eye disease screening in Liverpool over a 5-year period.
The researchers assessed whether AMD was present in the photographs as well as the severity of the condition. They then compared people who were taking metformin to people who weren’t taking the medication.
“They said that the metformin group had 37% lower odds of developing intermediate AMD over the 5-year period compared to the cohort of people who weren’t taking metformin.
“Most people who suffer from AMD have no treatment, so this is a great breakthrough in our search for new treatments,” said Nicholas Beare, MD, a clinician researcher at the University of Liverpool who led the research, in a statement.
“What we need to do now is test metformin as a treatment for AMD in a clinical trial. Metformin has the potential to save many people’s sight.”
Theodore Leng, MD, a professor of ophthalmology at Stanford University, said the Liverpool study shows some association between metformin use and the development of intermediate AMD, but noted some limitations in the findings.
Leng wasn’t involved in the research, but cited a
He noted that the 2025 study looked at 1.6 million people compared to the 2,000 people in the Liverpool study.
“I would say that more studies are needed before we can make a specific recommendation on the use of metformin in those who have AMD or are at risk and want to prevent the development of AMD,” Leng told Healthline.
Benjamin Bert, MD, an ophthalmologist at MemorialCare Orange Coast Medical Center in Fountain Valley, CA, agreed that more research on the potential benefits of metformin as an AMD treatment is needed.
He pointed out that the Liverpool study only included people ages 50 and older with diabetes. He said it would be important to learn how metformin might help a broader range of the general population.
He added that additional treatments for macular degeneration would be beneficial.
“Anything that can help slow the progression of macular degeneration or keep it stable would be welcome,” Bert told Healthline.
Age-related macular degeneration affects almost
AMD is a disease that is caused by the deterioration of the macula, a small area in the center of the retina in the back of the eye.
It typically causes central vision loss, but doesn’t generally produce total blindness or affect peripheral vision. The vision impairment, however, can be so severe that an individual may become legally blind.
If left untreated, AMD is the leading cause of vision loss in people over the age of 60.
There are two types of AMD.
Dry macular degeneration affects about 85% to 90% of people with AMD. It’s caused by small yellow deposits called drusen developing under the macula.
Wet macular degeneration affects the remaining 10% to 15% of people with AMD. It occurs when abnormal blood vessels develop under the retina and macula. This is the advanced form of AMD that can cause rapid and severe vision loss.
AMD is a progressive disease that gets more serious over time. The condition can occur in one eye or in both eyes.
There are a number of early symptoms of AMD. They include:
- trouble seeing in dim light
- vision is less clear from far-away as well as close-up objects
- colors aren’t as sharp
Later symptoms for dry AMD include:
- continued reduction in central vision
- the need for brighter lighting
- blurriness
- difficulty recognizing faces
Later symptoms for wet AMD include:
- blurry spot in your field of vision
- dark spot in the center of your vision
- hazy vision
There is no cure for AMD, but there are treatments that can help improve vision. These include medications as well as specific laser treatments.
Leng said a vitamin formulation known as
Bert said these multi-vitamins have proven to effective in treating AMD.
“They’ve been shown to be quite beneficial,” he said.
Leng also noted that a light therapy known as photobiomodulation was authorized a year ago by the Food and Drug Administration to treat dry AMD.
Metformin is a generic prescription medication used to help manage type 2 diabetes.
The daily oral tablet works by decreasing sugar production in the liver, reducing sugar absorption from food, and improving the body’s insulin sensitivity.
Unlike GLP-1 drugs, metformin is not approved as a weight-loss treatment, although some people may lose weight as a side effect of the medication.
Other side effects include:
- diarrhea
- nausea
- headache
- indigestion
Metformin also carries a “black box” warning for risks associated with developing lactic acidosis.
Metformin is usually prescribed by a physician along with a healthy diet and regular exercise for people with type 2 diabetes.
It is one of the most widely prescribed medications for type 2 diabetes management because it is generally effective and well-tolerated.
A 2015 study concluded that metformin can reduce diabetes risks by 18% over a 15-year period.
It is also sometimes prescribed for people with prediabetes as a way to prevent the development of type 2 diabetes.
Bert said he would caution people who don’t have diabetes about taking metformin to treat AMD. He said the medication could reduce blood sugar to low enough levels to develop hypoglycemia.
“That would be the primary concern,” he said.
Leng says there a number of things people can do to reduce the effects of AMD. They include:
- regular eye exams with an ophthalmologist, perhaps as often as every 6 months
- taking the AREDS2 vitamin formulation
- wearing sunglasses or a wide brim hat when outside
- avoiding exposure to tobacco smoke
- eating a healthy diet such as the Mediterranean diet
- exercising regularly
Berg agreed that overall health is important because the eyes can be sensitive to health issues in other parts of the body.
“Anything that brings benefits to the body will also be beneficial to the eyes,” he said.
Leng concluded by saying that metformin should not be considered a stand-alone treatment for AMD.
“Regarding metformin specifically, current evidence does not support prescribing it solely for AMD prevention or treatment in patients without diabetes,” he said. “For patients already taking metformin for diabetes, continuation is reasonable given its overall safety profile, but expectations for AMD protection should be tempered.”