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

Purpose: To evaluate the diagnostic accuracy of retinal nerve fiber layer thickness (RNFLT) by spectral-domain optical coherence tomography (OCT) in primary open-angle glaucoma (POAG) in eyes of African (AD) and European descent (ED)

Design: Comparative diagnostic accuracy analysis by race.

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 the African Descent and Glaucoma Evaluation Study.

Methods: Spectralis (Heidelberg Engineering GmbH) and Cirrus (Carl Zeiss Meditec) OCT scans were taken within 1 year from each other.

Main Outcome Measures: Diagnostic accuracy of RNFLT measurements.

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.

Conclusions: OCT-RNFLT has lower diagnostic accuracy in eyes of AD than those of ED. This finding 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 difference.

*Author(s): Mahmoud T. KhalafAllah, Linda M. Zangwill, James Proudfoot, Evan Walker, Christopher A. Girkin, Massimo A. Fazio, Robert N. Weinreb, Christopher Bowd, Sasan Moghimi, Gustavo De Morales, Jeffrey Liebmann, Lyne Racette

Clinical Paper of the Month manager: Anthony Khawaja