Congenital and acquired colour vision deficiency among population in North Kordofan State of Sudan

Abstract

Background: Congenital colour vision deficiency (CVD) is an x-linked chromosome disorders which, predominantly occurring in males. This disorder results from abnormalities in one or all three-cone type's photoreceptors. It is mainly affect long wavelength photopigments (red) and middle wavelength photopigments (green). However, the acquired CVD is due to ocular or general pathology as well as due to prolonged use of some medications, which is mostly affect short wavelength photopigments (blue). Objective: This study aimed to evaluate the prevalence of hereditary and acquired CVDs among Sudanese population in North Kordofan State. Materials and Methods: This is a population-based crossed-sectional study of 1100 subjects, their age ranged from 10 to 80 years, the mean age of subjects was 40.4 ± 16.6 (standard deviation) were selected from three districts and 110 subjects were selected from each set. Investigations included visual acuity using Snellen tumbling E-chart, refraction using retinoscopy, colour vision using Ishihara and City University colour vision tests, external eye using torch and magnifier and evaluation of internal eye and ocular media using direct ophthalmoscope. Results: A total of 1216 subjects were invited to participate in the study and 1100 were examined resulting in a participation rate of 91%. The findings revealed that 61 (5.5%) had CVD, 49 (9.0%) were males and 12 (2.2%) were females. The prevalence of congenital (red-green) CVD was 39 (3.5%) which was high in males 37 (6.8%) than females 2 (0.4%). The prevalence of congenital CVD was found associated with males (P