Intraoperative versus postoperative suture adjustment after penetrating keratoplasty

Purpose. To study the effects of running suture adjustment for reduction of astigmatism after penetrating keratoplasty. Suture adjustments performed during surgery and during the early postoperative and late postoperative periods were retrospectively compared. Methods. We studied 53 patients who received running suture adjustment after penetrating keratoplasty, either intraoperatively (ISA group, n = 18), early (<2 weeks) postoperatively (EPSA group, n = 19), or late (>1 month) postoperatively (LPSA group, n = 16). Refractive and topographic astigmatism and corneal topography were examined at 1, 3, and 6 months after surgery. Results. Overall mean refractive astigmatism and topographic astigmatism at 6 months were 2.55 ± 1.61 D and 3.12 ± 1.89 D, respectively (mean ± SD). The mean refractive astigmatism and topographic astigmatism were 1.88 ± 1.04 D and 2.35 ± 1.35 D in the ISA group, 2.32 ± 1.17 D and 2.70 ± 1.21 D in the EPSA group, and 3.01 ± 1.62 D and 4.62 ± 2.51 D in the LPSA group, respectively (mean ± SD). The LPSA group demonstrated significantly increased topographic astigmatism compared to the ISA group (p = 0.0048) and the EPSA group (p = 0.015). Although 31.6 and 25.0% of the EPSA and LPSA groups, respectively, did not require postoperative suture adjustments, more eyes (10/18 eyes, 55.6%) in the ISA group did not require the procedure. Conclusions. Early postoperative suture adjustment was more effective than late postoperative adjustment. Intraoperative suture adjustment may further reduce final astigmatism and the necessity for postoperative suture manipulation.