AAO 2023: Weight loss drug does not appear to worsen diabetic eye disease in most patients

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Amid a surge in popularity of the diabetes drug semaglutide for its ability to help people lower their glucose levels and better manage their weight, one potential side effect continued to give both phyicians and patients pause: vision loss.

A new review of real-world data offers some reassuring news. It appears that most people taking semaglutide do not develop diabetic retinopathy or experience a worsening of existing diabetic retinopathy. The study will be presented this week at 127th annual meeting of the American Academy of Ophthalmology in San Francisco.

According to the news release, the lead researcher Zeeshan Haq, MD, from Retina Consultants of Minnesota, said further investigation is even more important now since the U.S. FDA recently greenlighted use of semaglutide as a weight loss aid. Ophthalmologists need more data to inform screening guidelines, monitoring schedules, and patient counseling.

According to AAO, diabetic retinopathy causes vision loss and blindness in people who have diabetes. It happens when high blood sugar levels damage blood vessels in the back of the eye. Semaglutide effectively decreases blood sugar and it reduces appetite and causes the stomach to empty more slowly, so that a person feels fuller faster. 

However, according to the news release, the effectiveness of semaglutide in causing a sudden drop in blood sugar, also known as glucose levels, is also a reason for concern. Previous studies have found a link between a rapid improvement in glucose control and the risk of worsening diabetic retinopathy. While the increased risk is temporary and often manageable with current treatment protocols, this paradox warrants increased attention from ophthalmologists.

The research team accessed the IRIS Registry to evaluate data from more than 48,000 adults with type 2 diabetes treated with injectable semaglutide. According to the news release, the subjects were between 51 and 75 years old and were treated between 2013 and 2021.

After two years of treatment:

• Only 2.2 percent of eyes with no or background diabetic retinopathy experienced a worsening of diabetic retinopathy.
• In eyes with early-stage disease (mild or moderate nonproliferative diabetic retinopathy), 3.5 percent of eyes showed a worsening of diabetic retinopathy.
• Nearly 60 percent of eyes with advanced disease (severe nonproliferative or proliferative diabetic retinopathy) experienced an improvement in their diabetic retinopathy.

Haq pointed out in the news release that although results are promising for people with diabetes hoping to use semaglutide for weight loss and other health benefits, more research is definitely needed. 

Moreover, Hag noted in the news release the study has significant limitations including its retrospective observational design, lack of a control group, and a lack of pre- and post-initiation of semaglutide comparisons.

“In particular, the impact of semaglutide initiation on short- and long-term outcomes in potentially high-risk patients, such as those with severe non-proliferative or proliferative diabetic retinopathy, should be investigated further,” Hag said. “Ultimately, diabetic patients who are considering semaglutide should consult with their primary and eye care providers regarding their individual situation.”

Researchers are working to learn more about the long-term effects of semaglutide on diabetic retinopathy in people with type 2 diabetes. A prospective clinical trial called FOCUS will evaluate the long-term effects of semaglutide in addition to diabetes medication on diabetic retinopathy. The study is expected to conclude in February 2027.