African Ancestry-Specific OCT Normative Database Alters Retinal Nerve Fiber Layer Classification in Primary...

Structural differences in the retinal nerve fiber layer (RNFL) of African ancestry individuals are underrepresented in the Cirrus HD-OCT normative database. Our prior study reclassified primary open-angle glaucoma (POAG) color codes using RNFL data from healthy African ancestry controls. This study compares color-code classification between the Cirrus database and our reclassification for African ancestry POAG cases.

787 eyes from the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study.

Eyes were staged using the Enhanced Glaucoma Staging System (GSS2), and RNFL thickness color codes were reclassified based on an African ancestry-specific cohort.

The POAAGG reclassification model reported fewer abnormal yellow and red color codes (16.4% and 6.3%) than Cirrus (18.0% and 9.4%, P<0.001). Reclassification shifted 12.8% of red codes to yellow/green and 23.0% of yellow codes to green (P<0.001). Among stage 1 glaucoma eyes, 19.0% of red codes and 23.1% of yellow codes shifted to greener classifications (P=0.04). Similar patterns were seen in quadrant- and stage-specific analyses.

The discrepancy in POAG color-code classification suggests that an ancestry-conscious normative database may reduce overdiagnosis in African ancestry individuals.

Our study showed lower occurrence of primary open-angle glaucoma in African ancestry patients when taking their ancestry into consideration compared to the Cirrus HD-OCT classification.