Changes in Astigmatism after Suture Removal in Penetrating Keratoplasty

ABSTRACT

PURPOSE: To study a refractive change after suture removal and to evaluate some factors for this change in penetrating keratoplasty. METHODS: We studied 53 eyes of 47 patients who had undergone penetrating keratoplasty. Subjective refraction and best corrected visual acuity were measured in all eyes before and after the removal of sutures. We also classified the subject eyes based on suture removal time, degree of astigmatism before suture removal, recipient trephine size and compared the change of astigmatism within the groups. RESULTS: Suture removal decreased the astigmatism by an average of 0.81 diopter (D) (p=0.02) and increased the best corrected visual acuity by an average of 0.17 (p=0.005). These results show that corneal astigmatism tends to decrease more with early suture removal (p=0.010), higher degree of astigmatism before suture removal (p<0.05) and smaller size of recipient trephine (p=0.014). CONCLUSIONS: The removal of entire suture after penetrating keratoplasty decreases corneal astigmatism. Furthermore, the outcome is influenced by suture removal time, degree of astigmatism before suture removal, and recipient trephine size.