Miller, Aaron M.

SIGNIFICANCE This pilot randomized trial, the first to evaluate a specific base‐in relieving prism treatment strategy for childhood intermittent exotropia, did not support proceeding to a full‐scale clinical trial. Defining and measuring prism adaptation in children with intermittent exotropia are challenging and need further study. PURPOSE This study aimed to determine whether to proceed to a full‐scale trial of relieving base‐in prism spectacles versus refractive correction alone for children with intermittent exotropia. METHODS Children 3 years old to those younger than 13 years with distance intermittent exotropia control score of ≥2 points on the Intermittent Exotropia Office Control Scale (Strabismus 2006;14:147–150; 0 [phoria] to 5 [constant]), ≥1 episode of spontaneous exotropia, and 16 to 35∆ by prism‐and‐alternate‐cover test, who did not fully prism adapt on a 30‐minute in‐office prism‐adaptation test were randomized to base‐in relieving prism (40% of the larger of distance and near exodeviations) or nonprism spectacles for 8 weeks. A priori criteria to conduct a full‐scale trial were defined for the adjusted treatment group difference in mean distance control: “proceed” (≥0.75 points favoring prism), “uncertain” (>0 to <0.75 points favoring prism), or “do not proceed” (≥0 points favoring nonprism). RESULTS Fifty‐seven children (mean age, 6.6 ± 2.2 years; mean baseline distance control, 3.5 points) received prism (n = 28) or nonprism (n = 29) spectacles. At 8 weeks, mean control values were 3.6 and 3.3 points in prism (n = 25) and nonprism (n = 25) groups, respectively, with an adjusted difference of 0.3 points (95% confidence interval, −0.5 to 1.1 points) favoring nonprism (meeting our a priori “do not proceed” criterion). CONCLUSIONS Base‐in prism spectacles, equal to 40% of the larger of the exodeviations at distance or near, worn for 8 weeks by 3‐ to 12‐year‐old children with intermittent exotropia did not yield better distance control than refractive correction alone, with the confidence interval indicating that a favorable effect of 0.75 points or larger is unlikely. There was insufficient evidence to warrant a full‐scale randomized trial.

SIGNIFICANCE When exploring relationships among clinical measures and patient‐reported outcome measures in adults with convergence insufficiency, worse symptoms (Convergence Insufficiency Symptom Survey [CISS] score) seemed to be correlated with worse reading function domain score (Adult Strabismus‐20 quality‐of‐life questionnaire). After treatment, improved symptoms were associated with improved reading function quality of life. PURPOSE This study aimed to explore relationships between clinical measures and patient‐reported outcome measures in adults undergoing treatment for symptomatic convergence insufficiency. METHODS In a prospective multicenter observational study, we evaluated adults with symptomatic convergence insufficiency (i.e., clinical measures of near exodeviation, receded near point of convergence, reduced near positive fusional vergence; CISS score ≥21). Fifty‐seven participants treated with vision therapy/exercises (n = 35) or base‐in prism (n = 22) were analyzed. Spearman correlation coefficients ( R ) were used to assess associations among the three clinical measures and patient‐reported outcome measures (CISS, Diplopia Questionnaire, four Adult Strabismus‐20 quality‐of‐life domains) before treatment (baseline) and after 10 weeks and 1 year. Associations were interpreted to be present when the lower limit of the 95% confidence interval (CI) was moderate to strong ( R ≥ 0.4). RESULTS Among multiple exploratory analyses, the only moderate to strong baseline correlation was between worse CISS and worse Adult Strabismus‐20 reading function scores ( R = 0.62; 95% CI, 0.43 to 0.76). Regarding change in measures with treatment, the only moderate to strong correlations were between improved CISS and improved Adult Strabismus‐20 reading function scores for prism at 10 weeks ( R = 0.78; 95% CI, 0.52 to 0.91) and 1 year ( R = 0.85; 95% CI, 0.65 to 0.94) and for vision therapy/exercises at 1 year ( R = 0.78; 95% CI, 0.57 to 0.89). CONCLUSIONS In exploratory analyses, we found positive correlations between CISS symptom scores and reading function quality‐of‐life scores. The absence of correlations between symptoms and individual clinical measures is consistent with clinical experience that, in convergence insufficiency, symptoms and clinical findings can be discordant.