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

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Primary open-angle glaucoma (POAG) diagnosis relies on detecting structural changes, including retinal nerve fiber layer thickness (RNFLT).
• Spectral-domain optical coherence tomography (OCT) is a key technology for measuring RNFLT.
• Racial disparities in glaucoma prevalence and progression necessitate understanding diagnostic tool performance across different populations.

Purpose of the Study:

• To compare the diagnostic accuracy of RNFLT measurements using spectral-domain OCT between individuals of African descent (AD) and European descent (ED).
• To evaluate RNFLT diagnostic performance in identifying primary open-angle glaucoma (POAG) across racial groups.

Main Methods:

• Comparative diagnostic accuracy analysis was performed using data from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study.
• Spectralis and Cirrus OCT scans were obtained from 379 healthy eyes and 442 glaucomatous eyes (comprising AD and ED participants).
• Diagnostic accuracy was assessed using the area under the receiver operating curve (AUROC), with adjustments for potential confounders.

Main Results:

• Spectralis OCT-RNFLT showed significantly lower diagnostic accuracy in AD eyes (AUROC: 0.85) compared to ED eyes (AUROC: 0.91, P=0.04).
• Cirrus OCT-RNFLT also exhibited lower accuracy in AD eyes (AUROC: 0.86) versus ED eyes (AUROC: 0.90), though this difference was not statistically significant (P=0.33).
• These findings remained consistent after adjusting for age, central corneal thickness, axial length, disc area, visual field mean deviation, and intraocular pressure.

Conclusions:

• OCT-based RNFLT measurements demonstrate reduced diagnostic accuracy in individuals of African descent compared to European descent for POAG detection.
• This disparity in diagnostic performance was robust across two different OCT instruments and persisted after accounting for various confounding factors.
• Further research is warranted to elucidate the underlying reasons for these observed racial differences in RNFLT diagnostic accuracy.