What the diabetologist needs to know about the risk of non-arteritic anterior ischaemic optic neuropathy and GLP-1 receptor agonist use in patients with type 2 diabetes

Aim

Recent findings have raised concern about a potential association between semaglutide use and non-arteritic anterior ischaemic optic neuropathy (NAION), a rare form of permanent vision loss. This report provides a critical analysis of the current knowledge of GLP-1 receptor agonist (RA) use and risk of NAION in patients with type 2 diabetes (T2D).

Methods

A literature search strategy was conducted for all English-language literature with a systematic review of key references up to April 2025.

Results

Across studies including patients with T2D, the relative increase in NAION risk associated with the use of a GLP-1 RA, mainly semaglutide, ranged from nonsignificant to fourfold, while the absolute number of affected patients remained low. Given the retrospective design of the main studies, no causal link could be established between the use of GLP-1RAs and NAION. Some mechanistic hypotheses have been put forward without any being formally demonstrated to date. The profound metabolic and haemodynamic changes induced by GLP-1RAs might be the trigger of NAION in predisposed patients with an optic “disc-at-risk”, a potent anatomical risk factor easily detected by ocular examination.

Conclusion

Pending studies clarifying this risk, these findings call for cautious use of GLP-1 RAs, particularly in patients with ocular risk factors. Given the widespread use of GLP-1RAs, clinicians should be aware of this potential risk, without overshadowing the remarkable benefit of GLP-1RAs in patients with type 2 diabetes.