Comparison of Modified Anchored “Hang-Back Technique (HBT)” With Conventional HBT in Bimedial Rectus Recession

Purpose: We conducted a retrospective study to establish whether bimedial rectus recession (BMR) using a modified “hang-back technique” (HBT) is comparable with conventional HBT. Methods: Consecutive patients younger than the age of 16 underwent BMR during 1999 and 2000 with at least a 6-month postoperative follow-up period were included. In 1999, all patients had operations performed with conventional HBT, whereas those in 2000 were conducted with modified HBT. Angles of strabismus were measured preoperatively and at 2 weeks, 2 months, and 6 months postoperatively. Results: Thirty-nine and 43 patients underwent BMR using conventional and modified HBT respectively. Preoperative angles for near and distance were 43.6 (PD) versus 43.5 PD and 36.4 PD versus 36.8 PD. At 6 months' postop, the mean angles for near and distance were 6.4 PD Eso (range, 35 PD Eso - 40 PD Exo) and 5.4 PD Eso (range, 35 PD Eso - 35 PD Exo) in the conventional group: 8.1 PD Eso (range, 35 PD Eso - 20 PD Exo) and 6.3 PD Eso (range, 35 PD Eso - 25 PD Exo) in the modified group. The overall success rate (alignment to within 10 PD of orthotropia for distance and near) was similar between the two groups (conventional HBT:69.2% vs. modified HBT: 67.4%, P = 0.352). However, modified HBT was found to be associated with significantly lower consecutive exotropia rate postoperatively at 6 months (4.7% vs. 20.5%, P = 0.031). Conclusion: BMR using modified HBT is as effective as conventional HBT but with a significantly lower consecutive exotropia rate.