Related Experiment Video
Updated: Aug 7, 2026
The Rodent Model of Nonarteritic Anterior Ischemic Optic Neuropathy (rNAION)
Published on: November 20, 2016
Cup-to-disc ratio in GLP-1 RA Associated Non-Arteritic Anterior Ischemic Optic Neuropathy
Christian M Robertson1, Derrick S Fung1, Kyle H Smith1
1Baylor Scott & White Eye Institute, Department of Ophthalmology, Baylor Scott & White Medical Center, Temple, TX.
Purpose:
First: to determine whether the cup-to-disc ratio (CDR) of patients with GLP-1 RA associated nonarteritic anterior ischemic optic neuropathy (NAION) is similar to the CDR of NAION patients without GLP-1 RA exposure. Second: to stratify the odds of developing NAION based on CDR.
Design:
A retrospective, multi-center, case control study of the CDR of NAION cases diagnosed between 2018-2024 SUBJECTS AND CONTROLS: The Disc-at-Risk Study Group included 16 neuro-ophthalmology centers that reviewed medical records of 1,812 unaffected fellow eyes from 2,169 consecutive patients with NAION. The control group included both eyes of 465 patients.
Methods:
The study compared the unaffected fellow eyes of three groups of NAION patients: semaglutide users (117 eyes), non-semaglutide GLP-1 RA users (83 eyes) and no GLP-1 RA medications (1,612 eyes). Control eyes defined the distribution of CDR in the general population.
Main Outcome Measure:
CDR of unaffected fellow eyes of NAION patients with and without exposure to GLP-1 RA medications RESULTS: The average provider-estimated CDR in unaffected fellow eyes of NAION patients was 0.13 with no significant difference among the three groups. A measured CDR ≤ 0.40 was found in 94% of fellow eyes but only 56% of controls (p<0.001). A measured CDR ≤ 0.20 was found in 54% of fellow eye photographs but only 9% of controls (p<0.001). Eyes with a measured CDR ≤ 0.20 have the highest NAION odds (OR=46.3; 95% CI 23.0-93.4), and eyes with a CDR >0.20 and ≤ 0.40 had more modest odds (OR=6.8; 95% CI 3.5-13.2) compared with eyes with a measured CDR >0.40.
Conclusions:
NAION patients with and without exposure to GLP-1 RA medications have the same high prevalence of crowded optic discs. The odds of NAION are inversely proportional to CDR. Irrespective of GLP-1 RA exposure, eyes with a photo-measured CDR ≤ 0.20 have 46 times greater odds of NAION than eyes with a CDR > 0.40. Although the absolute risk of NAION is low, this quantification of NAION risk may help better inform patients concerned about NAION risk. This study does not assess whether GLP-1 RA medications are an independent risk factor for NAION.
