Comparison of objective refraction by open-field auto-refractor to conventional cycloplegic retinoscopy in teenagers with low ametropia

Objective To compare the objective refraction by open-field auto-refractor without cycloplegia and conventional mydriasis retinoscopy in teenagers with low ametropia. Methods A total of 78 male participants aged 15-l8 (16.23±1.42) years old were randomly selected from Grade 1 (2017) and Grade 2 (2016) students in teenager aviation school. The best corrected visual acuities of all the participants were greater than or equal to 1.0. The refraction of each participant was examined by openfield auto-refractor without cycloplegia (OF) and mydriasis retinoscopy (RS), and the spherical equivalent refraction (SER) of these two examinations were calculated and compared. The difference and correlation of SERs examined by OF and RS were tested by Wilcoxon rank-sum test and Spearman correlation test separately. Results The SER examined by OF was significantly lower than that by RS[-0.375 (-0.625, -0.125) D vs -0.250 (-0.500, 0.000) D, P=0.000]. The correlation between OF and RS was of statistical significance (r=0.765, P=0.000). Grouped by results of RS, when SER ≥ 0 D or -0.50 D< SER< 0 D,the SERs examined by OF were lower than those examined by RS (all P< 0.05), and the differences were -0.196 D and -0.198 D respectively, and the SERs by RS were moderately correlated with SERs by OF (r=0.485, P=0.026; r=0.546, P=0.002, respectively). When SER ≤ -0.50 D, there was no statistically significant difference in SERs between RS and OF with a high correlation (r=0.744, P=0.000). Conclusion The objective refraction by open-field auto-refractor without cycloplegia has no clinically significant difference with mydriasis retinoscopy in teenagers. It is reliable and may be an option of screening in conscription or regular health screening in teenager aviation schools.