advertisement

Editors Selection IGR 21-4

Glaucoma and Systemic Diseases: GLP-1 agonists could be protective against glaucoma incidence in diabetic patients

Comment by Keith Martin on:

There has been growing interest in the potential for systemic metabolic treatments to influence the risk of glaucoma onset and progression, especially given the complex interplay between vascular, metabolic, and neurodegenerative factors in the disease. In this context, the retrospective cohort study by Muayad et al. is both timely and thought-provoking.

Using the extensive TriNetX global database and careful propensity score matching, the authors compared outcomes in patients with type 2 diabetes mellitus (T2DM) initiated on either GLP-1 receptor agonists or metformin. They report a significantly reduced risk of developing primary open-angle glaucoma (POAG), ocular hypertension, and need for first-line glaucoma therapies in the GLP-1 cohort after 1, 2, and 3-years of follow-up.

The findings are compelling and align with preclinical studies suggesting that GLP-1 receptor agonists exert neuroprotective and anti-inflammatory effects on retinal ganglion cells. Importantly, the authors also propose several plausible mechanisms, including enhanced glycaemic control, reduction in intraocular pressure (IOP), and modulation of nitric oxide signalling. The breadth of the cohort—drawn from over 120 healthcare systems across 17 countries—lends weight to the generalisability of the results, and the consistent protective effect across multiple outcome measures is interesting.

There are, however, several caveats. The study relies entirely on coded health record data, with no access to individual clinical measures such as actual IOP values or visual field loss, limiting the precision with which glaucoma incidence and severity can be assessed. Although the authors attempted to match for ophthalmology access, surveillance bias remains a concern: patients receiving more frequent care are more likely to be diagnosed. Additionally, while the authors used sophisticated matching techniques, the potential for residual confounding factors - particularly related to unmeasured socioeconomic status, prescribing biases, and access to GLP-1 therapies - remains. It is also worth noting that the apparent protective effect emerged early, which may be difficult to reconcile with the slow, insidious course of POAG in many individuals.

Despite these limitations, the study significantly advances our understanding of the systemic factors that may modulate glaucoma risk. While causality cannot be established in this observational setting, these results offer an intriguing suggestion that GLP-1 receptor agonists may confer ocular benefits beyond glucose control. Further prospective, mechanistic, and interventional studies are now warranted to determine whether these agents might one day play a role in glaucoma prevention or therapy.

• ← Previous
• Next →