Role of inheritance and causes of childhood blindness: A multicenter study in Sudan

Aim: This study aims to study the causes of childhood blindness (CB), the impact of consanguineous marriage, and the role of inheritance. Methods: This was a cross-sectional observational study conducted in Khartoum State at Sudanese National Association of the Blinds, Alnoor Institute and Umbada Center for the Blinds. Individuals whose visual acuity was 3/60 or less were registered as blind since birth were included in the study.Demographic data and history, Snellen, visual acuity test, both subjective and objective refraction, and a questionnaire were used to assess the family history of blindness and parents' relationship. Results: Infantile blindness was found greater (75.8%) in Sudanese male than females (24.2%) population; (χ2 = 32.03, P = 0.000). Most of the participants' age (62.5%) was <5 years (χ2 = 7.5, P = 0.006) and ranged between 8 and 42 with a mean of 23.1 ± 8.1-year-old. The most frequent causes of infantile blindness were found to be congenital cataract (28.3%), corneal abnormalities (28.3%), optic nerve defects (27.5%) followed by retinal abnormalities (5.83%) and structural abnormalities (3.33%); however, 6.67% of the participants were without obvious ocular anatomical defects (χ2 = 56.5, P = 0.000). Most of the participants (69.2%) showed a positive family history of blindness (χ2 = 17.63, P = 0.000) and in 92.6% of the participants, the parents were related to each other (71.7% had 1st degree cousins; 9.2% 2nd degree cousins; 11.7% far relationship, (χ2 = 139.8, P = 0.000).Inherited factors were found in 65% of participants who were born blind (49.2% autosomal recessive, 5% autosomal dominant, 10.8% Xlinked whereas 35% were isolated cases, (χ2 = 61.67, P = 0.000). Conclusion: Most of the causes of CB are avoidable or preventable. Structured strategies should be developed for screening, referring, and early diagnosis with genetic analysis awareness among communities.Inherited disorders are still counted as significant causes among CB group. Raising health risks of consanguineous marriage might well help in avoidance of such blindness. However, screening, early detection, and rehabilitation programs will reduce the harm of such causes in children.