Association of Ocular Conditions With Narrow Angles in Different Ethnicities

PurposeTo quantify the predictive strength of anterior chamber area (ACA), anterior chamber volume (ACV), anterior chamber width (ACW), lens vault (LV), iris thickness (IT), and iris area (IArea) for 2 angle width parameters, trabecular-iris space area (TISA750) and angle opening distance (AOD750) at 750 μm from the scleral spur, in different ethnicities.DesignProspective, cross-sectional study.MethodsAnterior segment optical coherence tomography images for 166 white, 90 African, 75 Hispanic, and 132 Chinese subjects were analyzed. First, ACA, ACV, ACW, LV, IT, and IArea were compared among ethnic groups. Second, associations of TISA750 and AOD750 with ACA, ACV, ACW, LV, IT, and IArea were investigated within each ethnic group using multivariable linear regression models, standardized regression coefficients (β), and coefficients of determination (R2).ResultsSignificant ethnic differences were observed in ACA, ACV, ACW, LV, IT, and IArea (all P < .05). ACA, ACV, and LV were significant predictors of TISA750 and AOD750 in all ethnic groups (all P < .001). ACW and IT were significant predictors of AOD750 in white and African subjects (all P < .05). ACW and IT were significant predictors of TISA750 in white subjects (all P < .05). IArea was a significant predictor of AOD750 in Chinese (P < .05). ACA, ACV, and LV had the highest predictive strength for both TISA750 and AOD750 in all ethnic groups based on β and R2.ConclusionsDespite ethnic differences in ACA, ACV, ACW, LV, IT, and IArea, the same 3 anterior segment parameters (ACA, ACV, and LV) were the strongest predictors of angle width (TISA750 and AOD750) in all 4 ethnic groups.