A 60-year-old woman in Bengaluru with poorly controlled diabetes experienced sudden vision loss after eight to nine months of treatment with a glucagon-like peptide (GLP)-1 drug. Initially, the medication improved her glycaemic control and aided weight loss, but she was later diagnosed with non-arteritic anterior ischaemic optic neuropathy (NAION), commonly known as eye stroke.
Ocular Risks of GLP-1 Drugs
GLP-1 drugs, widely used for diabetes management and weight loss, mimic natural hormones 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 on March 20, ophthalmologists are flagging potential ocular risks.
Dr Divyansh K Mishra, VR ocular oncology and vitreoretinal specialist at Sankara Eye Hospital, explained that risks fall into two categories. The most common is progression of diabetic retinopathy, a diabetes-related condition affecting the retina. Rapid tightening of blood sugar levels may worsen retinopathy. The second category, though rarer, is more serious: eye stroke, specifically NAION, which affects the optic nerve and leads to sudden, often irreversible vision loss.
Dr Preethi Sridharan, vitreoretinal surgeon at Nethradhama Super Speciality Eye Hospital, noted that patients with pre-existing diabetic retinopathy may develop macular oedema, swelling in the central retina that impairs vision. Other complications include vitreous haemorrhage and further progression of retinopathy, potentially resulting in significant visual decline.
Need for India-Specific Data
Doctors emphasise that while global studies have flagged risks, India-specific data is still needed. They 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 that 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, poor baseline glycaemic control, or long-standing diabetes are at higher risk.
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 a prescription and should follow a treatment plan guided by a diabetologist with regular ophthalmic evaluations.
