Refractive Error among Strabismic Children in Ilorin, Nigeria

Abstract

Objectives: This study was conducted to determine the pattern of refractive errors among a group of strabismic children. Methods: A cross sectional survey was carried out among primary school children in Ilorin South Local Government area of Kwara State, Nigeria to isolate those with manifest strabismus. These children with manifest strabismus then underwent a full ocular examination followed by an objective refraction using a Topcon 8000R autorefractometer without cycloplegia and then a subjective refraction. Results: Of the 7288 children screened, there were 32 cases of strabismus (22 esotropia and 10 exotropia) consisting of 19 males and 13 females (M: F = 1.5:1). Hypermetropia was the commonest refractive error among the children (50%) followed by astigmatism (30%) and myopia (20%). There was more astigmatism among esotropic children (66.7%) compared to exotropic children (33.3%). Majority of the hypermetropia (85%) was associated with esotropia while most of the myopia (62.5%) was associated with exotropia. The prevalence of significant refractive error was found to be 34.4% (95% CI, 34.2 – 34.6). A great proportion of the refractive errors are in the mild and moderate category. It was only among hypermetropic children that refractive errors greater than ±5.0DS/Cyl in any meridian was found. Conclusion: There is a high prevalence of significant refractive error in the study population. Hypermetropia is the dominant refractive error seen in this study and most of it is found among the esotropic children. There was more myopia among exotropic children compared to esotropic ones but the difference is not statistically significant.

Keywords: Refractive Error, Strabismus, Children, Ilorin