A large population study reveals a novel association between congenital color vision deficiency and environmental factors.

Abstract

To assess the associations between the prevalence of congenital color vision deficiency (CVD) and genetics and environment, represented by place of origin (ethnic background) and place of birth, respectively. This is a retrospective study of the computerized database of the northern recruitment center of Israel of 53,895 consecutive male Jewish conscripts 16-19years old, who completed the medical profiling process between 1988 and 2011. CVD was diagnosed using the 24-pseudo-isochromatic plate Ishihara test. Associations of CVD prevalence with sociodemographic variables, anthropometric indices, refractive errors, and mainly place of origin and place of birth were tested by both univariate analysis and multivariate regression models. Elevated BMI (obesity) and blood pressure (hypertension), as well as myopia, were all positively associated with congenital CVD. The composition of the study population provides a unique opportunity to investigate the relationship between ethnicity and environment. The prevalence of CVD significantly differs among subpopulations of different ethnic background as well as among those who were born in different geographical locations. Additionally, differences in the prevalence of CVD (1.2-1.6%) were observed among conscripts from the same origin, who were born in Israel, compared to those who were born elsewhere. Both place of origin (p < 0.01) and place of birth (p < 0.05) were associated with the prevalence of CVD in a multivariable regression model. This study affirms previously established associations of CVD with certain variables and reveals a possible novel association of CVD with environmental factors.