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.