Glucagon-Like Peptide-1 Receptor Agonists and Ocular Outcomes: Metabolic Transition, Retinal Vulnerability, and Risk-Stratified Monitoring.
This narrative review synthesizes evidence from randomized controlled trials, meta-analyses, and observational studies through 2026 to examine the effects of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dual incretin-based therapies on a range of ocular outcomes. The authors report that recent meta-analyses indicate an overall neutral long-term risk profile for diabetic retinopathy and macular edema with these agents. They describe a transient early worsening of diabetic retinopathy observed primarily in patients with advanced baseline disease undergoing rapid HbA1c reduction, framing this as a "metabolic transition phenomenon" rather than direct retinal toxicity—an interpretation supported by data from the SELECT trial, in which no increased ocular risk was found in a non-diabetic population. The review also notes observational signals suggesting possible protective associations with glaucoma and age-related macular degeneration, a potential safety concern regarding nonarteritic anterior ischemic optic neuropathy at low absolute incidence, and emerging evidence of benefit in ocular surface homeostasis and uveitis. Limitations include reliance on observational data for several signals and the inherent constraints of a narrative review design. The authors conclude that risk-stratified ophthalmic monitoring, aligned with a cited 2025 expert consensus, is preferable to routine treatment avoidance in high-risk diabetic patients.
Why this grade: This is a narrative review synthesizing existing trials, meta-analyses, and observational studies rather than generating primary data, so it is graded as a review rather than a direct human evidence tier.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and dual incretin-based therapies provide marked reductions in glycosylated hemoglobin (HbA1c), body weight, and cardiovascular risk. As global adoption expands and recognition of their broad metabolic benefits grows, clinical attention is shifting toward potential secondary complications, including ocular manifestations, during rapid metabolic improvement. This narrative review synthesizes evidence from randomized trials, meta-analyses, and observational studies up to 2026 to evaluate the effects of GLP-1-based therapies on various ocular outcomes. Recent meta-analyses demonstrate an overall neutral long-term risk for diabetic retinopathy (DR) and macular edema. Transient early worsening of DR occurs primarily in patients with advanced baseline disease and rapid HbA1c reductions, reflecting a metabolic transition phenomenon rather than intrinsic retinal toxicity. This interpretation is supported by 2024 cardiovascular outcome data in a non-diabetic population (e.g., Semaglutide Effects on Cardiovascular Outcomes in People with Overweight or Obesity [SELECT] trial) that showed no increased ocular risk. Observational data suggest protective associations with glaucoma via intraocular pressure-independent neuroprotection and a reduced risk of incident age-related macular degeneration, but a potential safety signal for nonarteritic anterior ischemic optic neuropathy has emerged in recent datasets. Although the absolute incidence remains low, risk with a delayed temporal pattern appears to be increased in specific cohorts. Emerging evidence also suggests potential benefits in ocular surface homeostasis and uveitis. Accordingly, following a 2025 multidisciplinary expert consensus, risk-stratified ophthalmic monitoring, rather than routine treatment avoidance, is recommended during the early metabolic transition in high-risk diabetic patients.
Educational summary of published research — not medical advice. License: cc by-nc. Full text is shown only where licensing permits.