Change in horizontal comitance after symmetric versus asymmetric strabismus surgery

Abstract

IntroductionHorizontal strabismus surgery outcomes evaluate alignment in primary gaze, yet misalignment in side gaze also causes symptoms. Here we elucidate the effect of surgical approach on strabismus comitance to inform surgical planning.MethodsRecords of patients undergoing horizontal strabismus surgery over a 3.5-year period were reviewed. Inclusion criteria included patients with side gaze measurements recorded <6 months before and <1 year after surgery. Minimum follow-up was 6 weeks. Main outcome measure was change in comitance (difference between right and left gaze before and after surgery).ResultsOf the 95 patients who met inclusion criteria, 79 (83%) were comitant preoperatively, of whom 6 developed postoperative incomitance. Of 16 with incomitant strabismus preoperatively, all of whom had asymmetric surgery, 3 (19%) were restored to comitance. The largest change in comitance occurred with 1 muscle surgery (7), then 3 muscle (5), 2 muscle (4), and 4 muscle (3). Of the 6 cases developing postoperative incomitance, 83% had unilateral surgery, but 1 muscle versus 2 muscle surgery showed no difference in induced incomitance.DiscussionAsymmetric strabismus surgery was associated with changes in postoperative comitance. Unilateral surgery was associated with induced postoperative incomitance. Single muscle surgery produced the largest change.ConclusionsUnilateral surgery is a powerful tool for treating patients with incomitance, but it can cause incomitance in patients who were previously comitant. This should be factored into surgical planning, especially in patients who are prone to diplopia or who are sensitive to the social implications of suboptimal reconstruction. IntroductionHorizontal strabismus surgery outcomes evaluate alignment in primary gaze, yet misalignment in side gaze also causes symptoms. Here we elucidate the effect of surgical approach on strabismus comitance to inform surgical planning. Horizontal strabismus surgery outcomes evaluate alignment in primary gaze, yet misalignment in side gaze also causes symptoms. Here we elucidate the effect of surgical approach on strabismus comitance to inform surgical planning. MethodsRecords of patients undergoing horizontal strabismus surgery over a 3.5-year period were reviewed. Inclusion criteria included patients with side gaze measurements recorded <6 months before and <1 year after surgery. Minimum follow-up was 6 weeks. Main outcome measure was change in comitance (difference between right and left gaze before and after surgery). Records of patients undergoing horizontal strabismus surgery over a 3.5-year period were reviewed. Inclusion criteria included patients with side gaze measurements recorded <6 months before and <1 year after surgery. Minimum follow-up was 6 weeks. Main outcome measure was change in comitance (difference between right and left gaze before and after surgery). ResultsOf the 95 patients who met inclusion criteria, 79 (83%) were comitant preoperatively, of whom 6 developed postoperative incomitance. Of 16 with incomitant strabismus preoperatively, all of whom had asymmetric surgery, 3 (19%) were restored to comitance. The largest change in comitance occurred with 1 muscle surgery (7), then 3 muscle (5), 2 muscle (4), and 4 muscle (3). Of the 6 cases developing postoperative incomitance, 83% had unilateral surgery, but 1 muscle versus 2 muscle surgery showed no difference in induced incomitance. Of the 95 patients who met inclusion criteria, 79 (83%) were comitant preoperatively, of whom 6 developed postoperative incomitance. Of 16 with incomitant strabismus preoperatively, all of whom had asymmetric surgery, 3 (19%) were restored to comitance. The largest change in comitance occurred with 1 muscle surgery (7), then 3 muscle (5), 2 muscle (4), and 4 muscle (3). Of the 6 cases developing postoperative incomitance, 83% had unilateral surgery, but 1 muscle versus 2 muscle surgery showed no difference in induced incomitance. DiscussionAsymmetric strabismus surgery was associated with changes in postoperative comitance. Unilateral surgery was associated with induced postoperative incomitance. Single muscle surgery produced the largest change. Asymmetric strabismus surgery was associated with changes in postoperative comitance. Unilateral surgery was associated with induced postoperative incomitance. Single muscle surgery produced the largest change. ConclusionsUnilateral surgery is a powerful tool for treating patients with incomitance, but it can cause incomitance in patients who were previously comitant. This should be factored into surgical planning, especially in patients who are prone to diplopia or who are sensitive to the social implications of suboptimal reconstruction. Unilateral surgery is a powerful tool for treating patients with incomitance, but it can cause incomitance in patients who were previously comitant. This should be factored into surgical planning, especially in patients who are prone to diplopia or who are sensitive to the social implications of suboptimal reconstruction.