Early intervention is linked with superior outcomes in patients who develop consecutive exotropia following vertical muscle transposition (VRT) for sixth nerve palsy, according to a case series published in Eye.
Researchers reviewed medical records of patients who underwent VRT for chronic sixth nerve palsy from January 2008 to December 2019 at 2 centers and identified a total of 164 cases. They noted that 9 patients (5.5%) developed consecutive exotropia following surgery, but did not observe significant correlations with respect to age, gender, time from onset to surgery, preoperative angle of deviation, degree of limitation of abduction, or type of surgical method used (P =.325, .924, .281, .127, .156, and .531, respectively). In total, 5 patients received full-tendon muscle transposition, 3 patients had the Hummelsheim procedure, and 1 patient had the Jensen procedure. The mean angle of consecutive exotropia was 26±9 Δ (range: 10–40 Δ), and was reduced to 21±15 PD following the second procedure. Of the 9 patients with consecutive exotropia, 7 continued to experience residual exotropia ≥10Δ, while the exotropia was corrected in the 2 remaining patients. The investigators noted that the 2 patients with favorable post-surgical outcomes allowed a shorter lapse of time between the 2 procedures than the other 7 participants.
Researchers highlight the necessity of early intervention. “The outcome of surgery for the overcorrection was unsatisfactory with the majority of cases showing little improvement even after removal of the augmentation sutures or even complete reversal of the transposition,” they state. “The only two cases which showed improvement of this overcorrection were those who had very early re-intervention surgery; namely 1 and 3 weeks after the initial overcorrection, as compared to the other seven cases, in which the second surgery was performed at 4 months at earliest.”
Study limitations include the retrospective nature and small sample size.
Elkamshoushy A, Awadein A, Elhilali H, Hassanein DH. Overcorrection after vertical muscle transposition with augmentation sutures in sixth nerve palsy. Eye. Published online January 15, 2022. doi:10.1038/s41433-021-01660-5