Strabismus is defined by non-coaxial eyes. In bilateral cases, this operation can be done unilaterally or bilaterally. This study evaluated the effectiveness, results, and unilateral or bilateral strabismus surgery complications. This clinical trial was performed in 2021 in Ahwaz, Iran, on 70 patients with bilateral strabismus candidates for surgical treatments. Patients were randomly divided into two groups: patients who underwent surgery in one eye (R&R) and patients who underwent surgery in both eyes (bilateral resection). The deviation before surgery, the first day after surgery, the first week, one month, and six months after surgery were measured. The deviation reduction in the two groups was compared with each other. Also, the rate of postoperative refraction, the need for reoperation, complications of surgery (including red eyes, enophthalmos, limited eye movements, etc.), and patient satisfaction were recorded and compared. 23 patients that underwent unilateral surgery (R&R) and 47 patients that underwent bilateral surgery. The data indicated a significantly higher frequency of red-eye in 1 day and one week after the surgery in the unilateral group (P= 0.02 and P= 0.01 respectively) and substantially higher eye discharges in patients undergoing unilateral surgery (P= 0.04). We also showed that diplopia was more frequent in unilateral group 1 week, one month, and six months after surgeries (p= 0.03, P= 0.04, and P= 0.03 respectively). A significantly higher frequency of restricted eye movement was observed in the unilateral group 1 month after operations (P= 0.03). 80.8% of the bilateral surgery group and 8.7% of patients in the unilateral group were satisfied with their condition (p-value = 0.04). Performing bilateral strabismus surgery could have significantly lower minor complications compared to unilateral approach.

Keywords: strabismus, surgery, unilateral, bilateral, complication.