The Journal of the Association of Physicians of IndiaAug 3, 2026

Glucagon-based Treatments and Vision Loss Risks in India: Weighing Benefits and Cautions

GLP-1 Therapies Weekly Brief ↗PubMed ↗DOI ↗

Updated Aug 4, 2026

Abstract

Emerging evidence suggests a possible association between glucagon-like peptide-1 receptor agonists and ocular adverse events, including nonarteritic anterior ischemic optic neuropathy (NAION).

Pharmacovigilance analyses and cohort studies indicate an association with early worsening of diabetic retinopathy.
Nonarteritic anterior ischemic optic neuropathy (NAION) is noted as a potentially irreversible cause of sudden vision loss in adults over 50.
Regulatory agencies, including the WHO and European Medicines Agency, recognize NAION as a very rare adverse effect of semaglutide.
Proposed mechanisms for these ocular events include altered blood flow to the optic nerve, sympathetic vasoconstriction, and rapid changes in blood sugar levels.
In India, where there is a high prevalence of diabetes and limited access to eye care, even rare adverse effects could have a significant public health impact.

Simplified

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dual incretin therapies such as tirzepatide have transformed the management of type 2 diabetes mellitus and obesity, with expanding cardiometabolic indications and rapid market growth globally and in India. However, emerging postmarketing evidence has raised concerns regarding ocular safety. Pharmacovigilance analyses, cohort studies, and case reports suggest an association between GLP-1-based therapies and ophthalmic adverse events, including early worsening of diabetic retinopathy and, more concerningly, nonarteritic anterior ischemic optic neuropathy (NAION)-a potentially irreversible cause of sudden vision loss in adults over 50 years. Although the absolute risk appears very low, regulatory agencies, including the WHO and European Medicines Agency, now recognize NAION as a very rare adverse effect of semaglutide, and similar signals are being explored for other agents, suggesting a possible class effect. Proposed mechanisms include altered optic nerve head perfusion, sympathetic-mediated vasoconstriction, and rapid glycemic shifts affecting vascular autoregulation; however, causality remains unproven. In India, where over 100 million adults live with diabetes and obesity rates are rising, even rare adverse events may translate into substantial public health impact, particularly given limited access to ophthalmic care and increasing unsupervised drug use. We advocate a balanced approach: baseline ophthalmic evaluation in high-risk individuals, informed consent regarding visual symptoms, early referral for visual complaints, strengthened pharmacovigilance, and coordinated endocrinology-ophthalmology surveillance systems. As newer triple agonists approach clinical use, integrating ocular safety into prescribing frameworks is imperative. Metabolic gains must not come at the cost of preventable vision loss.

Glucagon-based Treatments and Vision Loss Risks in India: Weighing Benefits and Cautions

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