Analysis of 2-year spherical equivalent progression in emmetropic children with non-cycloplegic refraction: a retrospective chart review

Abstract

Background: We aimed to investigate children with an emmetropic non-cycloplegic refraction (NCR) to compare the difference in progression of NC spherical equivalent (SE) over 2 years between the children with emmetropic and hyperopic cycloplegic refraction (CR) values.

Methods: Through a retrospective medical record review, 59 children aged under 10 years were evaluated. Refractive error was calculated as the average of the SE values of both eyes. According to the CR results, children with emmetropia (-0.50 to 1.00 diopter [D]) were assigned to group 1 (n = 29), and those with hyperopia (≥ 1.00 D) were assigned to group 2 (n = 30). The prevalence of myopia and SE progression were compared over 2 years. Correlations between final SE progression and baseline age and refractive error were analyzed and multiple regression analysis was conducted. Receiver operating characteristic curves that achieved the best cutoff points to distinguish between the groups were calculated.

Results: Group 1 showed significantly myopic SE changes compared to baseline at the 1-year follow-up, and group 1 was significantly myopic compared with group 2 at the 2-year follow-up. Myopia prevalence was 51.7% in group 1 and 6.7% in group 2 after 1 year, and 61.1% and 16.7% after 2 years, respectively. In the correlation analysis, baseline age, baseline CR, and difference between CR and NCR showed significant correlations with the 2-year SE progression (r = -0.359, p = 0.005; r = 0.450, p < 0.001; r = -0.562, p < 0.001, respectively). However, NCR refractive error showed no significant correlation (r = -0.097, p = 0.468). In multiple regression analysis, baseline age (β= -0.082), and CR-NCR difference (β= -0.214) showed a significant effect on SE progression for 2 years. When an NCR value of 0.20 D was set as the cut-off value to distinguish between the groups, a sensitivity of 70% and specificity of 92% were obtained.

Conclusion: Even if NCR showed emmetropia, children with baseline CR values of emmetropia showed greater SE progression compared with those with hyperopia. Cycloplegia is essential to confirm the correct refractive status in children. It may be useful for predicting prognosis of SE progression.

Keywords: Cycloplegic refraction; Emmetropia; Myopia; Non-cycloplegic refraction; Spherical equivalent progression.