Macular Thickness and Associated Factors in African Immigrants: Insights from the Africans in America Study

Normative optical coherence tomography (OCT) databases may not be generalizable to Africans, one of the fastest growing populations in the United States. Given the paucity of normative OCT data in Africans, we evaluated macular thickness in African immigrants.

This cross-sectional study analyzed African-born participants enrolled in the Africans in America Study. They underwent history, physical, oral glucose tolerance tests, hemoglobin electrophoresis, and macular OCT (Cirrus HD-OCT). In the primary analysis, multivariable linear regression excluding eyes with retinopathy, glaucoma, or ocular hypertension was used to evaluate the association between the central subfield thickness (CST) and demographic, clinical, and metabolic factors. In the secondary analysis, multivariable analysis was used to evaluate the association between macular layer thicknesses and prediabetes status (prediabetes vs normal glucose tolerance). P values less than 0.05 and false discovery rate (FDR) within 10% were considered significant.

Six hundred forty-three eyes of 330 participants (60% male; mean age: 40 ± 11 years) were analyzed. The mean CST thickness for the cohort was 238.53 ± 21.48 µm. On average, women had a lower CST than men [-10.51 µm, 95% confidence interval: (-15.75, -5.26), P < 0.001, FDR < 0.001]. No significant associations were found between prediabetes status and the thickness of any macular layer.

These findings provide descriptive reference data on Cirrus-derived macular thickness measurements among African-born adults. Women had a lower CST, on average, than men. In contrast to prior studies, there was no difference in macular layer thicknesses between participants with prediabetes and those with normal glucose tolerance.