Surgical and Non-surgical Interventions for Intermittent Exotropia: A Systematic Review of Randomized Controlled Trials.

Intermittent exotropia is one of the most common forms of childhood-onset strabismus, characterized by an outward deviation of the eye that occurs intermittently. Treatment can be surgical, non-surgical, or a combination of both. Non-surgical treatments include occlusion therapy, the use of minus lenses to stimulate convergence, and orthoptic therapy consisting of fusion exercises. Surgery is recommended to normalize binocular function when the patient experiences an increased frequency of strabismus. Given the lack of a universal gold-standard treatment, the decision whether to perform surgery and the optimal timing of surgical intervention remain persistent challenges. This systematic review aims to assess and compare the effectiveness of surgical and non-surgical management of intermittent exotropia. It also aims to explore the factors associated with lower or higher success rates among different treatment approaches for intermittent exotropia. A systematic search of studies published in PubMed, Cochrane Library, and ScienceDirect was completed on the surgical and non-surgical management of intermittent exotropia. An investigator searched a set of medical databases for randomized controlled trials and controlled clinical trials in English published within the last 10 years to ensure relevance. Major outcomes of interest included motor alignment success and improvement in control of intermittent exotropia. Secondary outcomes included changes in angle of deviation, binocular function, recurrence rates, need for re-intervention, and treatment-related adverse events. The target population was intermittent exotropia patients who underwent surgical and non-surgical treatments. The quality of the studies included was evaluated using the Cochrane Risk of Bias 2 (RoB 2) tool for randomized trials. This systematic review comprised 13 studies, most of which were randomized controlled trials, with a small number of secondary analyses and post hoc analyses of randomized controlled trials. The majority of the research focused on pediatric populations; however, some included adult patients, and sample sizes varied from 40 to 306. The included studies comparing surgical and non-surgical management of intermittent exotropia and the study findings demonstrate that both management approaches can improve motor alignment and binocular function; however, the magnitude of success, sustainability, and timing differ between the approaches. Overall, both surgical and non-surgical treatments are effective for intermittent exotropia. However, outcomes vary depending on multiple factors such as age, treatment compliance, baseline deviation magnitude, and timing of intervention. In this context, treatment success depends on patient-specific characteristics and requires tailored approaches that account for them.