Suturing technique for control of postkeratoplasty astigmatism and myopia

Purpose: We previously demonstrated that selective suture removal reduces keratoplasty astigmatism; however, a myopic shift was induced with increasing number of interrupted sutures removed. This study is an attempt to determine the effects of a modified surgical technique on postkeratoplasty myopia, astigmatism, and anisometropia. Methods: Optical penetrating keratoplasties were performed on 92 eyes of 84 patients. The study group consisted of 92 consecutive penetrating keratoplasties performed using 12 interrupted 10-0 nylon sutures and a tight 12-bite continuous suture, and use of an average keratometry (K) reading of 46.00 diopters for eyes undergoing combined and intraocular lens (IOL) exchange procedures. All patients had refraction, keratometry, and videokeratoscopy postoperatively, starting at 6 weeks and at the completion of selective suture removal. Results: Prior to suture removal, the average spherical equivalent was -0.160 ± 3.59 diopters. It was -1. 58 ± 3.66 diopters at the completion of suture removal at 1 year and -1.44 ± 3.72 at the last follow-up visit, averaging 20.7 months. Final residual refractive, keratometric, and videokeratoscopic astigmatism was 2.81 ± 1.82, 4.19 ± 2.94, and 3.58 ± 2.03 diopters, respectively. Anisometropia, using the spherical equivalent of the operated and fellow eyes, was 2.49 ± 2.25 diopters at completion of the study. A best corrected visual acuity of 20/50 or better was achieved in 50 patients (59%). Conclusions: Low myopic spherical equivalent refraction and anisometropia with moderate residual astigmatism were achieved by using tighter continuous sutures, an average K reading of 46 diopters for calculation of IOL power, and selective removal of fewer sutures.