PURPOSE:This study aimed to identify baseline factors associated with greater myopia progression and axial elongation in children with myopia. METHODS:This study performed a post hoc analysis of data from a 30-month randomized trial of atropine 0.01% versus placebo in children 5 to <13 years old with baseline spherical equivalent refractive error (SER) of -1.00 to -6.00 D, astigmatism of ≤1.50 D, and anisometropia of <1.00 D SER. Data from atropine 0.01% and placebo groups were pooled given outcomes were similar. Baseline factors of age, SER, axial length, race, sex, parental myopia, and iris color were evaluated for association with changes in SER and with changes in axial length at 30 months (24 months on treatment and then 6 months off) using backward model selection. RESULTS:Among 187 randomized participants, 175 (94%) completed 30 months of follow-up. The mean change in SER was greater among younger children (-0.19 D per 1 year younger; 95% confidence interval [CI], -0.25 to -0.14 D; p<0.001) and children with higher myopia (-0.14 D per 1 D more myopia at baseline; 95% CI, -0.23 to -0.05 D; p=0.002). The mean change in axial length was also greater among younger children (0.13 mm per 1 year younger; 95% CI, 0.10 to 0.15 mm; p<0.001) and children with higher baseline myopia (0.04 mm per 1 D more myopia; 95% CI, 0.002 to 0.08; p=0.04). CONCLUSIONS:Younger children with higher myopia had greater myopic progression and axial elongation over 30 months than older children with lower myopia. Developing effective treatments to slow the faster myopic progression in younger children should be a target of further research.

Importance:Controlling myopia progression is of interest worldwide. Low-dose atropine eye drops have slowed progression in children in East Asia. Objective:To compare atropine, 0.01%, eye drops with placebo for slowing myopia progression in US children. Design, Setting, and Participants:This was a randomized placebo-controlled, double-masked, clinical trial conducted from June 2018 to September 2022. Children aged 5 to 12 years were recruited from 12 community- and institution-based practices in the US. Participating children had low to moderate bilateral myopia (-1.00 diopters [D] to -6.00 D spherical equivalent refractive error [SER]). Intervention:Eligible children were randomly assigned 2:1 to 1 eye drop of atropine, 0.01%, nightly or 1 drop of placebo. Treatment was for 24 months followed by 6 months of observation. Main Outcome and Measures:Automated cycloplegic refraction was performed by masked examiners. The primary outcome was change in SER (mean of both eyes) from baseline to 24 months (receiving treatment); other outcomes included change in SER from baseline to 30 months (not receiving treatment) and change in axial length at both time points. Differences were calculated as atropine minus placebo. Results:A total of 187 children (mean [SD] age, 10.1 [1.8] years; age range, 5.1-12.9 years; 101 female [54%]; 34 Black [18%], 20 East Asian [11%], 30 Hispanic or Latino [16%], 11 multiracial [6%], 6 West/South Asian [3%], 86 White [46%]) were included in the study. A total of 125 children (67%) received atropine, 0.01%, and 62 children (33%) received placebo. Follow-up was completed at 24 months by 119 of 125 children (95%) in the atropine group and 58 of 62 children (94%) in the placebo group. At 30 months, follow-up was completed by 118 of 125 children (94%) in the atropine group and 57 of 62 children (92%) in the placebo group. At the 24-month primary outcome visit, the adjusted mean (95% CI) change in SER from baseline was -0.82 (-0.96 to -0.68) D and -0.80 (-0.98 to -0.62) D in the atropine and placebo groups, respectively (adjusted difference = -0.02 D; 95% CI, -0.19 to +0.15 D; P = .83). At 30 months (6 months not receiving treatment), the adjusted difference in mean SER change from baseline was -0.04 D (95% CI, -0.25 to +0.17 D). Adjusted mean (95% CI) changes in axial length from baseline to 24 months were 0.44 (0.39-0.50) mm and 0.45 (0.37-0.52) mm in the atropine and placebo groups, respectively (adjusted difference = -0.002 mm; 95% CI, -0.106 to 0.102 mm). Adjusted difference in mean axial elongation from baseline to 30 months was +0.009 mm (95% CI, -0.115 to 0.134 mm). Conclusions and Relevance:In this randomized clinical trial of school-aged children in the US with low to moderate myopia, atropine, 0.01%, eye drops administered nightly when compared with placebo did not slow myopia progression or axial elongation. These results do not support use of atropine, 0.01%, eye drops to slow myopia progression or axial elongation in US children. Trial Registration:ClinicalTrials.gov Identifier: NCT03334253.

Purpose It has been suggested that children perceptually adapt to changes in retinal image size in the presence of anisometropia and therefore do not display clinically significant aniseikonia. However, given that early methods of eikonometry were not child-friendly, the prevalence of this condition in children is poorly understood. Retinal image size differences may be relevant in the discussion of amblyogenesis. The computer-based Aniseikonia Inspector Version 3 (AI3) uses a simple, forced-choice method and includes calibration for heterophoria. The present study is designed to evaluate AI3 by measuring background and induced aniseikonia in children aged 5 to 13 years.Methods All subjects were present for a standard-of-care eye examination and had at least 20/40 best-corrected visual acuity and no history of strabismus or amblyopia. Trials of AI3 were performed in the vertical direction only, using the 12-point test, and two trials were recorded. Each subject was randomized to have a 4% size lens added to either the right eye or the left eye. Two trials were performed in this manner, followed by two more trials with the size lens over the alternate eye.Results Eighteen children were enrolled; three subjects were not able to complete testing because of lack of attention or understanding. Results from each condition (background aniseikonia, induced aniseikonia OD, and induced aniseikonia OS) were averaged for each patient. With the 4% size lens over the OD, mean aniseikonia measured -3.83%. With the 4% size lens over the OS, mean aniseikonia measured 4.29%.Conclusions Most children were able to complete aniseikonia testing with AI3. Background aniseikonia was clinically insignificant (0.59%), and induced aniseikonia measurements were close to expected values using a 4% size lens. Aniseikonia Inspector Version 3 appears to be a useful means for measuring aniseikonia in a normal pediatric population. Further study in children with anisometropia is needed.