Estimated Prevalence of Monocular Blindness and Monocular Severe Visual Impairment in Children of Cross Rivers State, Nigeria
Aim: The aim was to report on the prevalence of monocular blindness/monocular severe visual impairment (MB/MSVI) in children found in Cross River State Nigeria, using the key informant method (KIM). Settings and Design: A cross‑sectional study using the KIM. Patients and Methodology: Key informants were trained to identify children with vision problems through recognition of pictures of disease conditions, observation of behavior of the child and discussion with villagers during house to house visits, school visits, church visits, or market visits. They were instructed to bring the children to a predetermined health center for examination by a pediatric ophthalmologist led team. The children were examined, and findings recorded on the World Health Organization/prevention of blindness and low vision recording form for children. Statistical Analysis Used: Data were entered into MS Excel, transferred and analyzed with STATA 11. Results: Among 994 children with suspected visual impairment, 21.5% were diagnosed as MB/MSVI, with a population prevalence of 0.18/1000 children in the state. Males accounted for 61%. The leading anatomical causes were the cornea in 41%, the whole globe in 20%, and lens‑related in 19%. Boys were 2.6 times (95% confidence interval: 1.4–4.7, P = 0.002) more likely to have trauma as an etiology compared with girls. Conclusions: Monocular blindness/monocular severe visual impairment children are essentially “one‑eyed” children at risk of becoming blind individuals. The prevalence of MB/MSVI is 2.25 times that of bilateral blindness and severe visual impairment in children in this population. The main anatomical causes, as well as ocular trauma, are largely avoidable. Trauma that is avoidable was a significant etiology in boys compared with girls. MB/MSVI adds to the burden for child eye care services.
Keywords: Child eye care services, monocular blindness, monocular severe visual impairment, Nigeria, ocular trauma