Racial Differences in Diagnostic Accuracy of Retinal Nerve Fiber Layer Thickness in Primary Open-Angle Glaucoma

center dot PURPOSE: To evaluate the diagnostic accuracy of retinal nerve fiber layer thickness (RNFLT) by spectral-domain optical coherence tomography (OCT) in primary openangle glaucoma (POAG) in eyes of African (AD) and center dot DESIGN: Comparative diagnostic accuracy analysis by race.center dot PARTICIPANTS: 379 healthy eyes (125 AD and 254 ED) and 442 glaucomatous eyes (226 AD and 216 ED) from the Diagnostic Innovations in Glaucoma Study and and Cirrus (Carl Zeiss Meditec) OCT scans were taken within 1 year from each other. center dot MAIN OUTCOME MEASURES: Diagnostic accuracy of RNFLT measurements. center dot RESULTS: Diagnostic accuracy for Spectralis-RNFLT was significantly lower in eyes of AD compared to those of ED (area under the receiver operating characteristic [AUROC] curve: 0.85 and 0.91, respectively, P = .04). Results for Cirrus-RNFLT were similar but did not reach statistical significance (AUROC: 0.86 and 0.90 in AD and ED, respectively, P = .33). Adjustments for age, central corneal thickness, axial length, disc area, visual field mean deviation, and intraocular pressure yielded similar results.center dot CONCLUSIONS: OCT-RNFLT has lower diagnostic accuracy in eyes of AD than those of ED. Thisfinding was generally robust across the 2 OCT instruments and remained so after adjustment for many potential confounders. Further studies are needed to explore the potential sources of this dif-ference. (Am J Ophthalmol 2024;259: 7-14. (c) 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ))