Bengaluru: A 60-year-old woman with poorly controlled diabetes was started on a glucagon-like peptide (GLP)-1 drug to improve glycaemic control and aid weight loss. While she initially responded well, she developed sudden vision loss after eight to nine months and was diagnosed with non-arteritic anterior ischaemic optic neuropathy (NAION), also known as eye stroke.GLP-1 drugs, widely used for diabetes management and weight loss, mimic the natural hormone to regulate blood sugar, slow digestion and reduce appetite. With domestic generic versions set to enter the Indian market following the expiry of the semaglutide patent — the active ingredient in drugs such as ozempic and wegovy — on March 20, ophthalmologists are flagging potential ocular risks.Dr Divyansh K Mishra, VR ocular oncology and vitreoretinal specialist at Sankara Eye Hospital, said the risks broadly fall into two categories. “One of the most commonly observed is the progression of diabetic retinopathy, a diabetes-related condition affecting the retina. When blood sugar is brought rapidly to very tight levels, there is a possibility that retinopathy may worsen. The second category is much rarer but more serious. There is a potential risk of eye stroke, specifically a condition called NAION. In such cases, the optic nerve is affected, leading to sudden vision loss, which unfortunately is usually not reversible,” he added.Dr Preethi Sridharan, vitreoretinal surgeon at Nethradhama Super Speciality Eye Hospital, said patients with pre-existing diabetic retinopathy may develop macular oedema, a swelling in the central retina that impairs vision. “Other complications include vitreous haemorrhage — bleeding inside the eye — and further progression of retinopathy, potentially resulting in significant visual decline,” she said.Doctors emphasise while global studies have flagged risks, India-specific data is still needed. They also caution that the drugs alone cannot be blamed, as some individuals are inherently more susceptible. Dr Adarsh S Naik, medical director and vitreoretinal surgeon at Vasan Eye Care, said, “Some analyses suggest while early-stage worsening may occur, long-term progression to advanced retinopathy may not increase and may even improve in some cases. Patients with pre-existing diabetic retinopathy or poor baseline glycaemic control, long-standing diabetes are at higher risk of developing complications.”Dr Rohit Shetty, clinician and translational scientist and director of Narayana Nethralaya, stressed a balanced approach. “This should not discourage the use of GLP-1 drugs in patients where they are medically indicated. Patients should be stratified into low-, medium- and high-risk categories based on their diabetic profile, eye fundus findings and overall health.”Experts also stress that patients should not take these medications without prescription and should follow a treatment plan guided by a diabetologist with regular ophthalmic evaluations.
