Comparison of suture-in and suture-out postkeratoplasty astigmatism with single running suture or combined running and interrupted sutures

PURPOSE: To evaluate postkeratoplasty astigmatism between two suture techniques 2 to 4 years postoperatively in a group of patients previously studied 9 months postoperatively. METHODS: Thirty-two patients who underwent penetrating keratoplasty were randomly assigned to; one of two groups. Group 1 (16 patients) had a 24-bite single running 10-0 nylon suture with postoperative suture tension adjustment; group 2 (16 patients) had combined 16-bite running and eight interrupted 10-0 nylon sutures with selective postoperative removal of interrupted sutures. During long-term follow-up, the running suture was removed in 19 patients (59%). RESULTS: Postoperative astigmatism was slightly lower in patients with the single running suture technique when sutures were in place and was slightly greater after the sutures were removed compared with the combined running and interrupted suture technique (sutures in: single running suture +/- SD, 2.6 +/- 1.2 diopters [five patients, 31%]; combined running and interrupted sutures, 3.8 +/- 1.1 diopters [eight patients, 50%]; sutures out: single running suture, 3.3 +/- 1.3 diopters [11 patients, 69%]; combined running and interrupted sutures, 2.8 +/- 1.5 diopters [eight patients, 50%]). These differences were not statistically significant (sutures in, P <.13; sutures out, P <.46). Averages of follow-up were group 1, 48.3 +/- 10.6 months and group 2, 46.3 +/- 13.0 months. Follow-up ranged from 23 to 60 months. CONCLUSIONS: Postoperative astigmatism 4 years after penetrating keratoplasty is similar for these two suturing techniques, with or without residual sutures. A single running suture results in more rapid visual rehabilitation and less early astigmatism compared with the combined interrupted and running suture technique.