Reoperation in Horizontal Strabismus and Its Related Risk Factors

Purpose: To determine the surgical outcomes and the related risk factors of the second operation in patients with horizontal deviations. Methods: In this interventional case series, a total of 119 patients with history of reoperation were included (39 exotropia and 80 esotropia). Cases with consecutive strabismus, muscular palsy, systemic disease, lack of ocular fixation and cases who had vertical deviation and dissociated vertical deviation (DVD)> 5pd were excluded. Unilateral or bilateral medial rectus (MR) or lateral rectus (LR) resection was performed if the preoperative remained deviation was less or more than 20 pd respectively. Success of the reoperation was considered if the postoperative angle of deviations was ≤10pd. Results: Unilateral and bilateral MR resection were performed in 26% and 74% of exotropic patients with more mean of dose response in unilateral cases.(2.8 vs 2.6) Generally, successful surgical outcomes were observed in 94.9% of exotropic patients. Unilateral and bilateral LR resection was also performed each in 50% of residual esotropic patients. Unilateral cases resulted in more dose response compared to bilateral ones (2.6 versus 2mm/pd). Successful surgical outcomes were observed in 83.8% of esotropic patients. None of variable was found to be the risk factor of reoperation in the both groups. Conclusion: Both LR and MR resection are easy and predictable surgical approaches with high success rate in eso- and exotropic patients, respectively.Generally MR res. is more effective than LR res. Unilateral operation is less recommended in RXT group due to it’s lower success compared to bilateral op