Extra Ocular Muscle Fenestration as a Weakening Maneuver for Surgical Management of Strabismus: A Randomized Pilot Clinical Trial

PURPOSE: This study aimed to evaluate the efficacy and safety of fenestration in comparison to the classic muscle recession as a weakening maneuver to horizontal and vertical extra ocular muscles in the surgical management of strabismus. PATIENTS AND METHODS: This is a pilot single blind parallel group randomized controlled trial with 1:1 allocation ratio. Male or female patients aged 1- to 60-years-old who were admitted to the Pediatric Ophthalmology and Strabismus Department for surgical correction of horizontal or vertical strabismus. Patients were randomly allocated by the envelop method to either group 1 (muscle fenestration, N=9) or group 2 (classic muscle recession, N=9). All participants were assessed at the first post operative day, at one week, and one month after the surgery for the outcomes. RESULTS: Postoperative ocular alignment evaluated at the first day, one week, and one month following the operation showed comparable results with no significant differences between both groups (p>0.05). The median postoperative pain score evaluated at the first day following the operation was significantly higher in fenestration group than recession group (the medians were 2.0 and 1.0, respectively, p=0.014). Alternatively, the medians of the pain score were equal in both groups at one week and one month postoperatively (p>0.999). One patient in the fenestration group developed progressive subconjunctival hemorrhage. In contrast, there was no postoperative complications in the recession group (p>0.999). CONCLUSION: Efficacy and safety of muscle fenestration for correcting horizontal or vertical strabismus was comparable to the classic muscle recession.