Nonarteritic Anterior Ischemic Optic Neuropathy in Black Patients

Abstract

PURPOSE

Prior studies have shown that nonarteritic anterior ischemic optic neuropathy (NAION) is uncommon in persons of Black race compared with those of White race, but the reasons behind this discrepancy remain unknown. Our goal was to analyze the systemic and ocular features of Black patients with NAION compared with White patients.

DESIGN

Retrospective, cross-sectional study.

METHODS

Self-reported race was collected from all patients with NAION seen between 2014 and 2022 from a single US neuro-ophthalmology service. All Black patients with NAION and a randomly selected sample of White patients with NAION were included. We collected information on hypertension, hyperlipidemia, diabetes mellitus, hypothyroidism, obesity, ischemic heart disease, atrial fibrillation, pacemaker insertion, chronic kidney disease, dialysis, anemia, obstructive sleep apnea, deep vein thrombosis, stroke, use of phosphodiesterase inhibitors, and smoking status. We reviewed color fundus photographs and optic nerve OCT images to assess cup-to-disc ratio and document the presence of optic disc drusen. Counterfactual random forest was used to estimate associations for each characteristic of interest by race controlling for the other exposures.

RESULTS

We included 32 Black patients with NAION (mean age 57 ± 11 years, 38% men) and 69 of 432 White patients (mean age 57 ± 15 years, 59% men). Time between NAION onset and neuro-ophthalmic examination was significantly longer in Black patients (1.5 to <3 months: odds ratio [OR], 4.07, P = .03; 6 to <12 months: OR, 6.05, P = .007). Chronic kidney disease (OR, 7.53, P = .003) and hemodialysis (OR, 13.69, P = .02) were significantly more frequent in Black patients. No significant differences in cup-to-disc ratio were present (0.15 to <0.25: OR, 2.83, P = .09; 0.25 to <0.35: OR, 0.56, P = .46; ≥0.35: OR, 0.66, P = .44).

CONCLUSIONS

Referral delay occurs in Black patients with NAION, likely due to its relative rarity and concern for alternate diagnoses. Black patients with NAION were substantially more likely to have chronic kidney disease and be on dialysis than White patients. Despite known racial differences in cup-to-disc ratio, we found no difference between Black and White patients with NAION, suggesting that the underlying proposed compartment mechanism is the same between races.