Overminus Lens Therapy for Children 3 to 10 Years of Age With Intermittent Exotropia

Abstract

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 PARTICIPANTSThis 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 MEASURESPrimary 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. RESULTSThe 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.

Rasch-calibrated Intermittent Exotropia Symptom Questionnaire for Children

“…This finding is likely a reflection of the modest improvement of intermittent exotropia control from the overminus lenses at 6 and 12 months (on-treatment) and lack of treatment effect at 18 months (off-treatment) 5 . The mean difference in control scores was 0.8 points at 12 months (95% CI, +0.5 to +1.0 points, on the 0- to 5-point scale) and 0.2 points (95% CI, −0.04 to +0.5) at 18 months 5 . The Child Intermittent Exotropia Symptom Questionnaire may not have been sensitive enough to detect a treatment group difference at 12 months, when the mean control scores were significantly different between groups 5 .…”

“…The exotropia control score was the mean of three assessments obtained over the course of an office visit. 5,12 Scatterplots were also created to display those relationships.…”

Comparison of Alternate Part-time Patching and Pencil Push-up Training for Patients with Intermittent Exotropia

“…The spherical equivalent refraction was between -6.00 diopter(D) and +1.00D. And patients diagnosed as IXT met the following criteria: (1) intermittent exotropia or constant exotropia at distance (the distance control assessment at baseline was performed three time and the average value ≥2 points); (2) intermittent exotropia, exophoria or orthophoria at near (the near control assessment at baseline was performed three times, at least one time ≤4 points); (3) ocular deviation measured using prism and alternate occlusion test was more than 15PD; (4) difference between the exodeviation at near and distance was less than 10PD (convergence insu ciency IXT was not included). Participants were not allowed to conduct nonsurgical management within 6 months before enrollment.…”

“…2 Current evidence shows that conservative treatment has a negative effect on reducing angle of exodeviation and improving fusional amplitudes. [3][4][5] As we all know, control ability is becoming more important in determining the time of surgical management of intermittent exotropia. [6][7] It has important clinical application value to assess the impact of conservative treatment on IXT.…”

Optimised minus lens overcorrection for paediatric intermittent exotropia: A randomised clinical trial

“…Whilst some studies have used the lowest possible minus lens to produce objective orthophoria, 8,13 others have used the maximum tolerable overcorrection 6 . Some prescribed the maximum minus possible without compromising best corrected visual acuity 14 and yet others have used a fixed overminus 3–5 depicting it as a ‘reasonable’ dose to induce fixed amount of accommodation 4 . Some published studies did not detail the basis of their overminus prescription 1,7 …”