Portable eye examination kit (Peek ® ) acuity versus tumbling E-chart in the screening for vision impairment among primary school children

Objectives: To compare the smartphone-based Peek visual acuity test and the Tumbling E-Chart in the screening for vision impairment by trained teachers among primary school pupils in Kaduna North local government area (LGA), Kaduna state. Materials and Methods: The study is a cross-sectional analytic study. A systematic sampling was done to select pupils in primary 1–6 from 11 schools that were randomly selected in Kaduna North LGA. Twenty-two primary school teachers were trained on the use of Tumbling E-chart and peek acuity, and they subsequently screened primary school pupils for vision impairment using both methods. Those with presenting visual acuity worse than 6/12 were referred to the principal investigator for further evaluation. The children were examined on-site, and treatment was offered. External eye examination was done with a pen torch by school teachers. Results: A total of 352 primary school pupils were assessed using both peek acuity and the Tumbling E-chart with a mean age of 10.3 ± 2.2 years. More females were involved in the study (54.6%). There was a good degree of agreement between the Tumbling E-chart and the Peek acuity, with Cronbach’s Alpha of 0.804. The Bland–Altman plot demonstrated majority of mean values within the limit of agreement for the two diagnostic tests. About two-thirds of the pupils preferred the Peek acuity, but there was no statistically significant difference by age and sex ( p > 0.05). The prevalence of vision impairment was 2.27%, and myopia was the most common refractive error (1.4%). Conditions other than refractive error contributed 27.2% of ocular morbidity. Conclusion: Peek acuity demonstrates a good degree of agreement with tumbling E-chart and may be a feasible alternative for school-based screening by trained teachers.