Refractive Accuracy and Visual Outcome by Self-Refraction Using Adjustable-Focus Spectacles in Young Children: A Randomized Clinical Trial

Abstract

Importance: Uncorrected refractive error is the most common cause of vision impairment in children. Most children 12 years or older can achieve visual acuity (VA) of 20/25 or better by self-refraction using adjustable-focus spectacles, but data on younger children are lacking.

Objective: To assess refractive accuracy, corrected VA, and factors associated with not achieving VA of 20/25 or better among children aged 5 to 11 years performing self-refraction with Adspecs adjustable-focus spectacles (Adaptive Eyecare), compared with noncycloplegic autorefraction and cycloplegic refraction.

Design, setting, and participants: This was a cross-sectional noninferiority trial conducted from September 2, 2015, to December 14, 2017. The study setting was an academic pediatric eye clinic. Children aged 5 to 11 years with uncorrected VA of 20/40 or worse in 1 or both eyes and without systemic or ocular conditions preventing best-corrected VA of 20/25 or better were enrolled. Children who had best-corrected VA worse than 20/25 were excluded. Study data were analyzed from September 2017 to June 2023.

Exposures: Children were taught to self-refract with adjustable-focus spectacles.

Main outcomes and measures: Spherical equivalent refractive error (using self-refraction, noncycloplegic autorefraction, and cycloplegic refraction) and VA (uncorrected and using self-refraction, noncycloplegic autorefraction, and cycloplegic refraction) for study eyes were evaluated. Potential predictors of failure to achieve VA of 20/25 or better with self-refraction were assessed using logistic regression.

Results: A total of 127 consecutive children were enrolled. After exclusions, 112 children (median [IQR] age, 9.0 [8.0-10.3] years; 52 boys [46.4%]) were included in the study. Mean (SD) spherical equivalent refractive power was -2.00 (1.52) diopters (D) for self-refraction, -2.32 (1.43) D for noncycloplegic autorefraction, and -1.67 (1.49) D for cycloplegic refraction. Mean (SD) difference in refractive power between self-refraction and noncycloplegic autorefraction was 0.32 (1.11) D (97.5% 1-sided CI, 0.11 to ∞ D; P < .001) and between self-refraction and cycloplegic refraction was -0.33 (1.15) D (97.5% 1-sided CI, -0.54 to ∞ D; P = .77). The proportion of children with corrected VA of 20/25 or better was 79.5% (89 of 112) with self-refraction, 85.7% (96 of 112) with noncycloplegic autorefraction, and 79.5% (89 of 112) with cycloplegic refraction (self-refraction vs noncycloplegic autorefraction: McNemar P value = .27; self-refraction vs cycloplegic refraction: McNemar P value > .99). Those failing to achieve best-corrected VA of 20/25 or better with self-refraction had higher astigmatism (odds ratio [OR], 10.6; 95% CI, 3.1-36.4; P < .001) and younger age (OR, 1.5; 95% CI, 1.1-2.2; P = .02).

Conclusions and relevance: Self-refraction among children aged 5 to 11 years may result in more myopic power than cycloplegic refraction but not necessarily to a clinically relevant degree. Although the proportion of children achieving VA of 20/25 or better with self-refraction using adjustable-focus spectacles did not differ from cycloplegic refraction, it was less likely among younger children and those with higher astigmatism.

Figure.. Flow Diagram of Preconsent Screening, Enrollment, and Study Procedures

NCAR indicates noncycloplegic autorefraction; SR, self-refraction; VA, visual acuity.