A comparison of ocular alignment success of hang-back versus conventional bilateral lateral rectus muscle recession for true divergence excess intermittent exotropia

Abstract

To assess whether hang-back or conventional bilateral lateral rectus muscle recessions were more successful in achieving a satisfactory postoperative ocular alignment in patients with true divergence excess intermittent exotropia. The medical records of consecutive patients with true divergence excess intermittent exotropia who underwent bilateral lateral rectus muscle recession using hang-back or conventional techniques were retrospectively analyzed. All surgeries were performed by a single surgeon using the same standard table of surgical dosage. We compared the preoperative characteristics and motor surgical outcomes between the two groups. Success was defined as alignment within 10(Δ) of intermittent exotropias at distance and near. Any amount of postoperative esotropia was considered a failure. A total of 42 patients were included: 13 in the hang-back group and 29 in the conventional group. The mean age at surgery, mean preoperative deviation at near and distance, mean amount of lateral rectus muscle recession, and mean follow-up duration were not statistically significantly different between groups. At the most recent follow-up, the conventional group had a significantly greater success rate (≤10(Δ) of intermittent exotropia) than the hang-back group (83% vs 31%, P = 0.0009). There was no statistically significant difference in the mean amount of lateral rectus recession between patients with successful and unsuccessful surgical outcomes in both groups. Within the limitations of this study, conventional bilateral lateral rectus recessions were more effective than hang-back recessions in achieving a successful postoperative alignment in patients with true divergence excess intermittent exotropia.