Factors associated with the effectiveness of part-time patching for intermittent exotropia in children.

Purpose: To evaluate the factors associated with the efficacy of low-dose part-time patching in children with intermittent exotropia (IXT).
Methods: In this prospective observational study, we enrolled 186 patients diagnosed with IXT. Outcome measures included office based control scales, magnitude of exo-deviation, and stereoacuity at near and distance after daily patching for 2 h. We analyzed the clinical data and demographic factors association with improvement of IXT.
Results: The study was completed by 152 subjects of total enrolled patients on a consecutive basis followed up for 1 year. Decrease in the magnitude of exo-deviation, improvement of control, and or gain of stereoacuity were observed in 31.6% patients of the recruited subjects after part-time patching. Multivariate analyses showed that prognostic factors determining improvement to part-time patching included convergence insufficiency (CI) type IXT ( p  = 0.016), poor distance stereopsis ( p  = 0.044), and large exotropic deviation at distance ( p  = 0.025).
Conclusions: CI-type exotropia, large distance magnitude of exo-deviation, or poor distance stereopsis appear to be associated with a better response to part-time patching. Therefore low dose part-time patching may be a useful non-surgical treatment alternative to delay surgery in these cases.