Analysis of differences between subjective and objective refraction results in myopic children and adolescents under different ciliary muscle functional states

Objective  To analyze the differences between subjective refraction and autorefraction in myopic children and adolescents under different ciliary muscle functional states.

Methods  A cohort study was conducted.A total of 98 myopic children and adolescents (196 eyes) aged 7-15 years who visited the Shanghai Eye Disease Prevention and Treatment Center from November 2023 to February 2024 were included by random sampling.All participants underwent cycloplegia with 1.0% cyclopentolate and completed both subjective refraction and autorefraction before cycloplegia, after cycloplegia and after recovery from cycloplegia.The spherical equivalent (SE) differences and differences in SE(ΔSE) between different conditions were compared.Proportion of ΔSE, differences in spherical power (ΔS), and differences in cylindrical power (ΔC) of objective and subjective refraction between different conditions within the clinically acceptable error range (-0.25 to 0.25 D) was calculated and compared.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Shanghai Eye Diseases Prevention & Treatment Center (No.2021SQ021).Written informed consent was obtained from guardian of each subject before any medical examination.

Results  The SE values obtained from autorefraction before cycloplegia, after cycloplegia, and after recovery from cycloplegia were -2.44(-3.47, -1.63), -2.13(-3.25, -1.50), and -2.38(-3.50, -1.66)D, respectively, with a statistically significant overall difference ( χ ²=148.36, P<0.001) and statistically significant differences in pairwise comparisons at different time points (all P<0.001); for subjective refraction, the SE values were -2.25(-3.50, -1.50), -2.19(-3.47, -1.45), and -2.28(-3.50, -1.50)D, respectively, with a statistically significant overall difference ( χ ²=43.48, P<0.001) and statistically significant differences in pairwise comparisons at different time points (all P<0.001).Subjective refraction ΔSE between before and after cycloplegia, after cycloplegia and after recovery from cycloplegia were significantly smaller than those of autorefraction ( t=2.84, 1.82; both P<0.001).There was no significant difference in ΔSE between subjective refraction and autorefraction between before cycloplegia and after recovery from cycloplegia ( t=-0.43, P=0.070).The proportions of subjective refraction ΔSE within the acceptable error range between before and after cycloplegia, before cycloplegia and after recovery from cycloplegia, and after cycloplegia and after recovery from cycloplegia were significantly higher than those of autorefraction ( χ ²=28.32, 11.82, 25.55; all P<0.001).The proportion of subjective refraction ΔS and ΔC both within the acceptable error range between before cycloplegia and after recovery from cycloplegia was 81.63%(160/196) and 79.59%(156/196) between after cycloplegia and after recovery from cycloplegia.

Conclusions  Subjective refraction is less affected by different ciliary muscle functional states.The differences in subjective refraction results under different ciliary muscle functional states are mostly within the acceptable error range.The subjective refraction results before or after cycloplegia can be used to better predict the subjective refraction results after recovery from cycloplegia.

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