Metformin is a medication that is commonly used in the treatment of diabetes. (Learn More) Researchers have found that metformin can protect the eyes from age-related macular degeneration, which is very common in older patients who have diabetes. (Learn More)

Some ophthalmologists estimate that a metformin prescription can give elderly patients another 10 years of functioning eyesight. (Learn More)

Metformin & Diabetes Treatment

It requires a multipronged approach to protect eyesight from the damage diabetes can cause, and metformin is often part of this treatment approach.

Metformin is a medication that is either used by itself or with other medications to treat type 2 diabetes (when the body does not use insulin typically and cannot manage the sugar levels in the blood). Metformin helps the body do this, by decreasing the amount of glucose (sugar) that is absorbed from food and the amount of glucose that is produced by the liver. Metformin also increases the body’s response to insulin, which the body would normally produce to control glucose levels in the blood.

Left untreated, diabetes and high blood sugar levels can lead to heart disease, kidney problems, nerve damage, stroke, and eye and vision issues. Patients with diabetes might have a higher risk of blindness because the excessive blood sugar levels in their blood might damage their eyes and their optic nerve.

Metformin can be very helpful in addressing these issues, but patients will also be encouraged to make lifestyle changes (like improving their diet and getting regular exercise) and frequently check their blood sugar levels to control their diabetes and their sugar levels.

How Metformin Protects Eyesight

Metformin is considered the “medication of choice” as the first option to treat type 2 diabetes. This is because it provides many other health benefits in addition to lowering blood sugar.

Metformin can reduce the risk of high blood pressure affecting vision, and some researchers have discovered that the medication can also reduce the development of age-related macular degeneration (AMD), which is the leading cause of vision loss among people over the age of 50. People who have diabetes are at a high risk for developing AMD.

The researchers, based in Taiwan, told the Annual Meeting of the American Academy of Ophthalmology in 2018 that patients on a prescription of metformin had a 50 percent lower risk of getting age-related macular degeneration compared with patients who were not taking the medication.

Protective Against Inflammation

This led the researchers to conclude that metformin had a “protective effect” on the eyes, shielding eyesight from the effects of AMD, such as:

  • Partial loss of vision.
  • Straight lines appearing wavy.
  • Blurry vision.
  • Seeing spots in the field of view.
  • Inability to see in low-light conditions.

The researchers theorized that because metformin has both anti-inflammation and antioxidation properties, it might reduce the occurrence of age-related macular degeneration. This is because inflammation and oxidative stress are part of the development of diabetes and AMD. Metformin has also been connected to improving eyesight in patients who have diabetic retinopathy. Researchers writing in the American Journal of Translational Research in 2017 investigated the underlying mechanisms of how metformin both delayed the development and reduced the severity of diabetic retinopathy. They concluded that metformin has a “previously unappreciated role [...] in the prevention of development of diabetic retinopathy.”

10 Years of Vision

Some researchers have found that metformin stimulates metabolism in the retinal cells of the eye, creating energy production that makes the cells stronger against the development of age-related macular degeneration. An ophthalmology researcher at the University of Florida College of Medicine explained that metformin “allows these cells in the retina to be harder and more resistant to damage.”

Metformin is an inexpensive, widely used medication without many documented side effects, so doctors are hopeful that more patients with diabetes will use it to stave off vision loss.

Metformin makes cells gather together and use glucose as an energy source. Keeping them at this level of functionality can reduce damage to DNA and the effects of oxygen being metabolized by high blood sugar levels. By activating a protective enzyme, metformin can protect eyesight from the effects of diabetes.

Doctors and researchers clarified that metformin is not a wonder drug for age-related macular degeneration, but they are confident that it can be prescribed on an even wider basis to help patients who are at risk for losing their vision. It can be the difference between patients progressing from the early stages of macular degeneration to the advanced stages of the condition.

For a patient who is 80 years old and starting to lose their vision due to complications from diabetes, ophthalmologists say that a metformin prescription could “give them another 10 years of vision.”

References

Metformin May Help Prevent Eye Disease in People With Type 2 Diabetes. (October 2018). Everyday Health.

The Association Between Diabetes and Age-Related Macular Degeneration Among the Elderly in Taiwan. (October 2018). Diabetes Care.

Diabetes Medication May Protect Against a Common Cause of Blindness. (October 2018). Science Daily.

Metformin Inhibits Development of Diabetic Retinopathy Through MicroRNA-497a-5p. (December 2017). American Journal of Translational Research.

Tests Show Common Diabetes Drug Slows Age-Related Vision Loss. (October 2018). University of Florida Health.