Evaluating the Diagnostic Accuracy of a Portable Autorefractor for Refractive Errors and Strabismus Detection in Children: A Multiclinic and Cross-sectional Study

Context: Refractive errors and strabismus are among the most common causes of preventable visual impairment in children. Early detection is essential for timely intervention to support normal visual and developmental outcomes. Aims: To evaluate the diagnostic accuracy of the Retinomax K-Plus 3, a portable autorefractor, in detecting refractive errors and strabismus among children aged 3–10 years. Settings and Design: A prospective and cross-sectional diagnostic accuracy study was conducted across three urban pediatric outpatient clinics affiliated with a tertiary eye care institution. Subjects and Methods: A total of 200 children (mean age: 6.7 ± 2.1 years) were enrolled. Each participant underwent vision screening using the Retinomax K-Plus 3, followed by a comprehensive cycloplegic eye examination conducted by licensed optometrists, which served as the reference standard. Diagnostic parameters including sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic (ROC) curve area under the curve (AUC) were calculated for both refractive error and strabismus detection. Subgroup analysis by age and assessment of inter- and intra-observer reliability was also performed. Statistical Analysis Used: Descriptive statistics, 2 × 2 contingency tables, Chi-square test, ROC curve analysis, and Cohen’s kappa for reliability assessment were used. AUC comparisons were made using the DeLong method. Significance was set at P < 0.05. Results: The Retinomax K-Plus 3 demonstrated high diagnostic accuracy for refractive error (sensitivity 89.3%, specificity 91.9%, AUC = 0.92 [95% confidence interval (CI): 0.88–0.96]) and strabismus (sensitivity 86.4%, specificity 90.5%, AUC = 0.89 [95% CI: 0.84–0.94]). No significant variation was found across age groups ( P > 0.05). Observer reliability was strong (κ = 0.89–0.91). False positives and negatives were minimal and primarily related to motion artifacts or borderline clinical thresholds. Conclusion: The Retinomax K-Plus 3 is a valid, user-friendly tool for pediatric vision screening. Its portability and high accuracy make it ideal for integration into school-based and community-level programs.