Assessment of visual acuity in school-aged children utilizing a smart phone application

Abstract

Background: The World Health Organization (WHO) estimates that approximately 19 million children are affected globally by visual impairment, primarily due to refractive errors, with a notable concentration in developing countries. Despite resource limitations in these regions, the conventional method of assessing visual acuity using Snellen chart faces challenges in early detection of vision anomalies; however, the advent of the Peek acuity application, designed for simplicity, accessibility, and affordability on smart devices, represents a pioneering advancement in global visual acuity assessment. Aim: The aim of this study is to evaluate the specificity and sensitivity of the Peek acuity application and compare its effectiveness with the gold standard Snellen chart. Materials and Methods: In a single-session study, we evaluated the visual acuity of 167 children aged 7 to 14 years from Future Complex Primary and Secondary School using both the Snellen chart and the Peek acuity smartphone program on Huawei Mate Pad-11. Visual acuity was quantified in logMAR units, with a focus on classifying it based on the “American Association for Pediatric Ophthalmology and Strabismus” guidelines, where a visual acuity worse than +0.2 logMAR necessitates specialist referral. Statistical analysis was performed using SPSS 29 to assess the performance of the Peek acuity program against the Snellen chart, which served as the gold standard for evaluating the overall characteristics and specific sensitivities of the students. Results: Among the 167 children included in the study, 85 were male and 82 were female, accounting for 50.9% and 49.1% of the participants, respectively. The mean visual acuity was +0.17 (±0.23) in the right eye and +0.17 (±0.22) in the left eye, while the Peek acuity measurements showed +0.11 (±0.17) in the right eye and +0.12 (±0.15) in the left eye. When assessing Peek acuity against the Snellen chart, the sensitivity was determined to be 52.1%, with a specificity of 96.2%. Additionally, the positive predictive value (PPV) was calculated to be 84.5%, the negative predictive value (NPV) at 83.6%, and the prevalence of visual impairment in this sample was 25.3%. Conclusion: The Peek acuity program presents itself as a viable option for early detection of visual impairments within school environments, primarily due to its cost-effectiveness and high specificity. Its added convenience contributes significantly to enhancing the sensitivity of detecting visual abnormalities, thus establishing its potential as an invaluable component of comprehensive vision screening initiatives.