Effect of Suture Removal on Refraction and Graft Curvature After Deep Anterior Lamellar Keratoplasty in Patients With Keratoconus.

Abstract

To evaluate the effect of suture removal on refraction and keratometry measurements after deep anterior lamellar keratoplasty (DALK). This retrospective study enrolled 54 keratoconus-affected eyes that underwent DALK. A combined suturing technique consisting of a 16-bite single running and 8-bite interrupted 10-0 nylon sutures was used at the time of keratoplasty. Selective interrupted suture removal was performed in a subgroup of patients to reduce postkeratoplasty astigmatism. In another subgroup, all sutures were removed at a single session. Adjustment of the running suture tension was not performed in any case. The effect of suture removal on refractive outcomes was investigated in the entire study group, and the 2 subgroups were compared. Mean patient age was 26.6 ± 6.7 years at the time of keratoplasty. The mean interval from surgery to complete suture removal was 17.4 ± 5.9 months. Compared with the pre-suture removal values, there was a significant increase in the magnitude of myopia (-1.12 ± 1.73 D, P = 0.001), refractive astigmatism (-0.89 ± 2.47 D, P = 0.04), mean keratometry (1.39 ± 1.64 D, P = 0.001), and keratometric astigmatism (2.61 ± 2.43 D, P < 0.001) after complete suture removal. Subgroup analysis revealed that selective removal of interrupted sutures was effective as long as remaining interrupted and running sutures were left in place. Complete suture removal was followed by an unpredictable and significant increase in post-DALK refraction and keratometry readings. In the subgroup that underwent early selective removal of interrupted sutures before complete suture removal, the desirable effects of this procedure significantly diminished after all remaining sutures were completely removed.