GLP-1 Drugs Show Promise in Reducing Risk of Age-Related Eye Diseases

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) — a class of drugs typically prescribed for type 2 diabetes and weight loss — may significantly reduce the risk of developing several common age-related eye diseases, including age-related macular degeneration (AMD) and glaucoma, according to a study published online earlier this year in Ophthalmology.

The study, based on an analysis of electronic health records (EHRs) from older patients in the United States, revealed that GLP-1RAs were associated with lower rates of age-related macular degeneration, as well as primary open-angle glaucoma (POAG), when compared with other common medications such as metformin, insulin, statins and aspirin.

Kevin Allan, M.D., Ph.D.

Earlier studies have indicated that GLP-1 drugs lower the risk of glaucoma. “Others have alluded to the potential protective effect in AMD, but we’re among the first to show it in a large database study,” lead author Kevin Allan, M.D., Ph.D., a resident at the Cole Eye Institute, said in a recent news release. “There are still many questions, and we don’t want to overextrapolate, but it’s exciting to find existing drugs that can potentially have an effect on a disease that currently has limited treatment options.”

Researchers examined the records of more than 9,600 patients aged 60 and older with at least five years of ophthalmologic follow-up and medication history. Among those taking GLP-1RAs, 84% had diabetes and a high average body mass index (BMI) of 36.2.

GLP-1RA users saw a significantly lower risk of developing AMD when compared with their propensity-matched peers on metformin, insulin and statins. These protective effects were confirmed across different timeframes and in older patient cohorts. The reduced risk became particularly evident after three years of GLP-1RA use and was also seen for AMD and primary open-angle glaucoma when compared with insulin. However, the medications showed no significant impact on cataracts or ocular hypertension.

“Other research groups have shown that metformin is potentially protective against developing dry AMD, so we wanted to compare it with GLP-1 receptor agonists,” Allan said. “We were excited to find that GLP-1 receptor agonists outperformed metformin. We then went a step further and demonstrated a protective effect compared to statins, which also have been thought to be anti-inflammatory and protective across numerous organ systems.”

The study’s authors propose that the eye-related benefits of GLP-1RAs may stem from their known anti-inflammatory, antioxidant and neuroprotective properties. In animal studies, these drugs have been shown to reduce inflammation in retinal cells and prevent cell death—mechanisms believed to contribute to age-related eye damage. Additionally, GLP-1RAs may modulate risk factors like obesity and cardiovascular disease, which are known to influence ocular health.

The researchers acknowledged several limitations, including reliance on diagnostic coding in a non-ophthalmology-specific database, lack of data on medication dose and adherence, and the inability to adjust for socioeconomic factors and other confounders. Nonetheless, the consistency of results across different patient comparisons and validation analyses strengthens the case for further exploration.

Another Cole Eye Institute study found no association between GLP-1 drugs and worsening diabetic retinopathy, countering earlier widespread research. This study, published last year in Ophthalmology Science, found no association between the use of the drugs and worsening diabetic retinopathy. This study evaluated nearly 1,000 patients with type 2 diabetes who were treated at the Cole Eye Institute between 2012 and 2023. About 700 of them took GLP-1 receptor agonists (e.g., semaglutide, dulaglutide, exenatide).

Another Cole Eye Institute study, this one published recently in the American Journal of Ophthalmology, showed no increase in risk of optic neuropathy.