Long-term results of single continuous suture adjustment to reduce penetrating keratoplasty astigmatism

Abstract

Purpose: To evaluate the long-term effect of single continuous corneal suture adjustment on reducing penetrating keratoplasty astigmatism after suture removal.

Methods: Patients were identified from the original study of single continuous penetrating keratoplasty suture adjustment to reduce corneal astigmatism who were followed for more than a year after suture removal. A matching unadjusted control group was selected in the same way from those patients in the original study undergoing penetrating keratoplasty during the 2 years before the development of suture adjustment. The corneal astigmatism was compared before adjustment (study group) or <3 months after surgery (control group), >4 months after suture adjustment, and >12 months after suture removal in both groups.

Results: A study group of 54 patients with suture adjustment and a control group of 45 patients without suture adjustment were identified. Before suture adjustment, the study group had an average keratometric astigmatism of 6.44 diopters (standard deviation [SD] = 2.51, range = 0.38-12.25), and the control group had 6.38 diopters (SD = 3.29, range = 2.75-16.00, p = 0.536). Compared to that in the unadjusted control group, the average penetrating keratoplasty astigmatism in the suture-adjusted group was reduced by 44.6% (2.36 diopters) 4.5 months after surgery and before suture removal (p = 0.0002) and by 25.4% (1.19 diopters) at least 12 months after suture removal (p = 0.011).

Conclusion: Postoperative adjustment of a single continuous corneal suture significantly reduces penetrating keratoplasty astigmatism after suture removal.