Refractive Error Change and Overminus Lens Therapy for Childhood Intermittent Exotropia.

Importance: Increased myopic shift was found to be associated with 1 year of overminus spectacle treatment for children with intermittent exotropia (IXT). Persistence of myopic shift after discontinuing overminus spectacles is unknown. Objective: To compare refractive error change over 3 years in children with IXT originally treated with overminus vs nonoverminus spectacles. Design, Setting, and Participants: This study was an 18-month extension of the Trial of Overminus Spectacle Therapy for Intermittent Exotropia cohort, which previously randomized children aged 3 to 10 years with IXT and baseline spherical equivalent refractive error (SER) between -6.00 diopters (D) and 1.00 D to overminus spectacles (-2.50 D for 12 months, -1.25 D for 3 months, and nonoverminus for 3 months) or nonoverminus spectacles. Children were recruited from 56 sites from July 2010 to February 2022. Data were analyzed from February 2022 to January 2024. Interventions: After trial completion at 18 months, participants were followed up at 24 and 36 months. Treatment was at investigator discretion from 18 to 36 months. Main Outcomes and Measures: Change in SER (cycloplegic retinoscopy) from baseline to 36 months. Results: Of 386 children in the Trial of Overminus Spectacle Therapy for Intermittent Exotropia, 223 (57.8%) consented to 18 months of additional follow-up, including 124 of 196 (63.3%) in the overminus treatment group and 99 of 190 (52.1%) in the nonoverminus treatment group. Of 205 children who completed 36-month follow-up, 116 (56.6%) were female, and the mean (SD) age at randomization was 6.2 (2.1) years. Mean (SD) SER change from baseline to 36 months was greater in the overminus group (-0.74 [1.00] D) compared with the nonoverminus group (-0.44 [0.85] D; adjusted difference, -0.36 D; 95% CI, -0.59 to -0.12; P = .003), with 30 of 112 (26.8%) in the overminus group having more than 1 D of myopic shift compared with 14 of 91 (15%) in the nonoverminus group (risk ratio, 1.8; 95% CI, 1.0-3.0). From 12 to 36 months, mean (SD) myopic shift was -0.34 (0.67) D and -0.36 (0.66) D in the overminus and nonoverminus groups, respectively (adjusted difference, -0.001 D; 95% CI, -0.18 to 0.18; P = .99). Conclusions and Relevance: The greater myopic shift observed after 1 year of -2.50-D overminus lens treatment remained at 3 years. Both groups had similar myopic shift during the 2-year period after treatment weaning and cessation. The risk of myopic shift should be discussed with parents when considering overminus lens treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02807350.

Overminus Lens Therapy for Children 3 to 10 Years of Age With Intermittent Exotropia: A Randomized Clinical Trial.

IMPORTANCE: This is the first large-scale randomized clinical trial evaluating the effectiveness and safety of overminus spectacle therapy for treatment of intermittent exotropia (IXT). OBJECTIVE: To evaluate the effectiveness of overminus spectacles to improve distance IXT control. DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial conducted at 56 clinical sites between January 2017 and January 2019 associated with the Pediatric Eye Disease Investigator Group enrolled 386 children aged 3 to 10 years with IXT, a mean distance control score of 2 or worse, and a refractive error between 1.00 and -6.00 diopters (D). Data analysis was performed from February to December 2020. INTERVENTIONS: Participants were randomly assigned to overminus spectacle therapy (-2.50 D for 12 months, then -1.25 D for 3 months, followed by nonoverminus spectacles for 3 months) or to nonoverminus spectacle use. MAIN OUTCOMES AND MEASURES: Primary and secondary outcomes were the mean distance IXT control scores of participants examined after 12 months of treatment (primary outcome) and at 18 months (3 months after treatment ended) assessed by an examiner masked to treatment group. Change in refractive error from baseline to 12 months was compared between groups. Analyses were performed using the intention-to-treat population. RESULTS: The mean (SD) age of 196 participants randomized to overminus therapy and 190 participants randomized to nonoverminus treatment was 6.3 (2.1) years, and 226 (59%) were female. Mean distance control at 12 months was better in participants treated with overminus spectacles than with nonoverminus spectacles (1.8 vs 2.8 points; adjusted difference, -0.8; 95% CI, -1.0 to -0.5; P < .001). At 18 months, there was little or no difference in mean distance control between overminus and nonoverminus groups (2.4 vs 2.7 points; adjusted difference, -0.2; 95% CI, -0.5 to 0.04; P = .09). Myopic shift from baseline to 12 months was greater in the overminus than the nonoverminus group (-0.42 D vs -0.04 D; adjusted difference, -0.37 D; 95% CI, -0.49 to -0.26 D; P < .001), with 33 of 189 children (17%) in the overminus group vs 2 of 169 (1%) in the nonoverminus group having a shift higher than 1.00 D. CONCLUSIONS AND RELEVANCE: Children 3 to 10 years of age had improved distance exotropia control when assessed wearing overminus spectacles after 12 months of overminus treatment; however, this treatment was associated with increased myopic shift. The beneficial effect of overminus lens therapy on distance exotropia control was not maintained after treatment was tapered off for 3 months and children were examined 3 months later. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02807350.

Monocular deprivation in an identical twin.

PURPOSE: The scientific literature contains minimal human studies of the effect of monocular deprivation on a single eye of twins. This report examines the effects of early visual deprivation on axial length measurements by comparing the refractive findings and axial length measurements of identical twins' 4 eyes, 1 visually deprived and 3 nondeprived. METHODS: A retrospective record review was performed on the medical records of identical 6-year-old Hispanic female twins. Both patients had received eye care at the University Optometric Center, State University of New York, for a period of at least 5 years. Subsequently, an Internal Review Board-approved prospective study was undertaken. Each twin received a comprehensive eye examination and an A-scan. RESULTS: The findings of the 3 nondeprived eyes were compared with those of the 1 deprived eye. The 3 nondeprived eyes had at least 20/20 visual acuity, low hyperopia or astigmatism, low with the rule keratometric findings, 12-mm corneal diameters, and A-scan results ranging from 21.0 to 21.55 mm. The remaining eye, which was visually deprived secondary to congenital cataract from birth to 6 months of age, had an aphakic refractive condition, decreased visual acuity, glaucoma, esotropia, and borderline microcornea. Keratometric findings were comparable with those of the other 3 eyes, whereas the A-scan finding was 25.16 mm. CONCLUSION: This case presented a unique opportunity to directly examine the effect of visual deprivation on axial elongation. Although other factors, such as glaucoma and borderline microcornea, may influence axial elongation, the findings in this patient indicate that a substantial portion, if not all, of the axial elongation can be attributed to early monocular deprivation.