Refractive errors in school children in Onitsha, Nigeria
AbstractObjectives: To determine the incidence and pattern of ametropia among school children.
Materials and Methods: Consecutive school children presenting at the Guinness Eye Center Onitsha between September 2001 and August 2002 with visual acuity of 6/9 or worse in at least one eye; complaints of visual blurring, eye strain, brow ache and or discomfort while reading were recruited into the study. Cycloplegic refraction on each child was performed using 0.5% tropicamide eye-drops. Post-cycloplegic tests were performed within 72 hours.
Results: Of the 306 children (M:F – 1:2) examined, 301 (98.4%) had ametropia. Spherical errors were namely, hyperopia 23 (7.5%); myopia 47 (15.4%). Astigmatism occurred in 231 (75.5%) namely hyperopic astigmatism 72 (31.2%); myopic astigmatism 159 (68.8%). Anisometropia was present in 80 (26.1%) children, 16 of whom did not improve with refraction. Generally older children (12 – 17 years) were more likely to have refractive errors than younger children (95%CI: 0.07, 0.31; p < 0.005). But there was no difference in the incidence of myopia between younger children (aged 6 – 11 years) and older children (95%CI: –0.08, 0.43; p > 0.05). While 41 (13.4%) had visual impairment in the better eye, 8 (2.6%) other children had uniocular blindness at presentation.
Conclusions: There is a high incidence of uncorrected refractive errors among school children, although many were of small degrees. The cooperation of parents and teachers is vital in identifying and treating this modifiable cause of poor academic performance and learning difficulties.
Keywords: refractive errors, school children, visual impairment, Nigeria
Nigerian Journal of Health and Biomedical Sciences Vol. 5(1) 2006: 114-117