Prevalence and pattern of strabismus in primary school pupils in Benin City, Nigeria

Abstract

Background: Strabismus is the most common amblyogenic factor and approximately 40% of children with manifest strabismus have amblyopia. In Nigeria, it is generally believed that strabismus is not common. However, few studies have been done to determine the prevalence of strabismus in Benin City, Edo State. Objective: This study aims to determine the prevalence and pattern of tropias and phorias in primary school children in Benin City.

Methods: This was a cross-sectional study carried out on primary school pupils in government schools located within Egor Local Government Council Area, Edo State.

Results: Two thousand one hundred and thirty-nine students (2139) were examined. There were 1024 males (47.87%) and 1115 females (52.13%). The overall prevalence of tropias in this study was 0.89%. Esotropia was seen in 0.56% (12 pupils, SE 0.03%) and exotropia in 0.33% (7 pupils, SE 0.02%) of the pupils. Infantile esotropia was the most common form of esotropia while alternating exotropia was the most common pattern of exotropia. 57.04% of the pupils had heterophoria.

Conclusion: The prevalence of manifest strabismus in Benin City was low however there should be training of non-ophthalmic staff such as teachers to detect and refer cases of strabismus.

Keywords: Children, Nigeria, pattern, prevalence, pupils, strabismus