The Effects of Nonsurgical Treatment in Intermittent Exotropia by Meta-Analysis

Abstract

Purpose: To understand research trends in domestic and foreign primary studies related to the effect of nonsurgical treatment of intermittent exotropia by meta-analysis, and to suggest clinical and theoretical implications based on the direction and magnitude of the nonsurgical treatment effect for intermittent exotropia. Methods: Of the thesis related to the effect of nonsurgical treatment of intermittent exotropia published in domestic and international journals and dissertations from 1990 to 2015, 15 papers selected from the inclusion and exclusion criteria were analyzed for meta-analysis. The effect size and variance of individual primary studies and overall effect size were calculated and then verified homogeneity. Also, the difference of effective size in different treatment methods by sub-group was verified. The treatment method, type of strabismus and age of treatment time were selected as variables to be considered for conducting the non-surgical treatment of intermittent exotropia, and the effect of each variable on treatment of intermittent exotropia were analyzed. Results: The overall effect size of non-surgical treatment of intermittent exotropia was -0.715. The order of effect size of the treatment method was orthoptics; -1.753, mixed treatment; -1.747, correction of refractive error; -1.295, minus lens overcorrection; -0.500 and then occlusion therapy; -0.281. The order of effect size of strabismus types was divergent excess; -2.111, convergence insufficiency; -1.171, and then basic; -1.220. The order of effect size of age groups was 13∼19 yrs.; -2.029, 7∼13 yrs.; -1.057, under 4 yrs.; -0.751 and then 4∼7 yrs.; -0.379. Conclusions: It is considered that the effect size in this study was analysed quantitatively the improving effect such as the decrease of deviation or the improvement of stereopsis and so on with the nonsurgical treatment in patients with intermittent exotropia, and the objective relevance of the nonsurgical treatment was suggested by these results.