Refractive outcomes of table-mounted and hand-held auto-refractometers in children: an observational cross-sectional study

Background To compare the refractive results of hand-held and table-mounted autorefractors. Methods We designed this study as an observational, cross-sectional study. We compared the mean spheric and cylinder power, spherical equivalent, Jackson cross-cylinder values, determined the limits of agreement (LoA), and evaluated the reliability of two autorefractors. Results We evaluated 256 eyes of 256 pediatric patients (mean age, 9.12 +/- 2.26 years; range, 5-16 years). 49% of the patients were female, and 51% were male. The Nidek HandyRef-K autorefractor measured relatively more astigmatism (P < 0.001) and less hyperopia (P = 0.024). The mean differences and 95% LoA were 0.06 D +/- 0.47 D (- 0.82 D to 0.98 D) in spherical power, 0.08 D +/- 0.28 D (- 0.47 D to 0.64 D) in cylindrical power, 0.11 D +/- 0.47 D (- 0.81 D to 1.01 D) in spherical equivalent, 0.02 D +/- 0.36 D (- 0.73 D to 0.69 D) in Jackson cross-cylinder power at 0 degrees, 0.005 D +/- 0.54 D (- 1.07 D to 1.06 D) in Jackson cross-cylinder power at 45 degrees(.) We found the difference within 0.50 D in 244 (95%) eyes for spherical power, in 245 (96%) eyes for cylindrical power, 228 (89%) eyes for spherical equivalent, 224 (87%) eyes for Jackson cross-cylinder power at 0 degrees, 213 (83%) eyes for Jackson cross-cylinder power at 45 degrees(.) When comparing devices, there were strong correlations for spherical power (Spearman's rho = 0.99, P < 0.001), cylindrical power (Spearman's rho = 0.88, P < 0.001), and spherical equivalent (Spearman's rho = 0.98, P < 0.001). Conclusion Two autorefractors showed clinically applicable agreement limits; excellent reliability for spherical power and spherical equivalent and good reliability for cylindrical power; high positive percent agreement for spherical and cylindrical power, spherical equivalent, Jackson cross-cylinder power at 0 degrees and 45 degrees. These results showed that both devices might be used interchangeably for screening of refractive error in children.