Drift of ocular alignment following strabismus surgery. Part 2: using adjustable sutures.

AIM To measure the drift of ocular alignment following strabismus surgery utilising adjustable sutures. METHODS 106 patients, aged 12 to 84 years, underwent adjustable suture strabismus surgery with a follow-up of 0.5-4 years (mean 24.3 months). RESULTS For all subjects measured on distant fixation, there was a mean undercorrection drift of 8.3 (SD 2.3) prism dioptres (PD) from week 1 to 48 months postoperatively (p = 0.005). Patients with exotropia demonstrated an undercorrection drift on distant fixation from week 1 to 2 years (mean 10.1 (3.5) PD, p = 0.023). Patients who underwent recession surgery developed a mean 9.1 (3.3) PD undercorrection drift from week 1 to 3 years (p = 0.031). Patients who had unilateral recession and resection surgery showed a mean 6.8 (2.9) PD undercorrection drift from week 1 to 18 months (p = 0.049). Patients with constant or intermittent postoperative stereopsis had a statistically significant undercorrection drift (</=5.1 PD) at certain postoperative periods (p<0.042), while those without stereopsis had no significant drift. CONCLUSION Most patients developed a general drift toward undercorrection, especially following recession or recession with resection surgery and those with exotropia. Surgeons should consider creating a mild overcorrection at the time of suture adjustment, while avoiding long-term diplopia.