Association of Age and Spherical Equivalent With Differences in Cycloplegic Refractive Effects Between Cyclopentolate...

Amblyopia and strabismus are common visual impairments linked to functional and social consequences in children. In this retrospective study, we compared the cycloplegic effects of two cycloplegic eye drops, cyclopentolate and atropine, and examined whether age and initial spherical equivalent (SE) influenced these effects.

We retrospectively reviewed electronic medical records from Kozawa Eye Hospital and Diabetes Center between 2001 and 2021. The primary outcome was the difference in SE between atropine and cyclopentolate (atropine minus cyclopentolate). As both eyes from the same patient could be included, multivariable generalized estimating equations (GEE) with an exchangeable working correlation structure clustered by patient identifier were used. Additional analyses included the Wilcoxon signed-rank test, Bland-Altman analysis, and Yeo-Johnson transformation of the outcome before multivariable modeling.

The analysis included 186 eyes from 93 patients (median age, 6.00 years). Median SE was 2.47 D under cyclopentolate and 2.75 D under atropine, with a significant paired difference (Wilcoxon signed-rank test, p < 0.001). Bland-Altman analysis showed a mean difference of +0.42 D, with 95% limits of agreement from -0.44 to +1.28 D, and no significant proportional bias (slope = -0.016, p = 0.300). In the multivariable GEE model, older age was associated with a smaller atropine-cyclopentolate difference (β = -0.034, 95% confidence interval (CI): -0.065 to -0.003, p = 0.031), and higher initial SE was also associated with a smaller difference (β = -0.032, 95% CI: -0.060 to -0.004, p = 0.023). Sex and eye laterality were not significantly associated with the difference.

Atropine produced a stronger refractive effect than cyclopentolate in this pediatric cohort. The atropine-cyclopentolate difference was smaller in older patients and in eyes with higher initial SE, supporting consideration of age and baseline refractive status when selecting cycloplegic agents in pediatric patients.