Modified suture removal does not improve visual results after PK

A modified suturing technique for penetrating keratoplasty had no significant effect on final spherical equivalent compared to a previous surgical technique, a clinical study found.

Use of tight continuous sutures and selective removal of fewer interrupted sutures only increased final astigmatism in eyes undergoing penetrating keratoplasty, the study found.

Dilek Dursun, MD, and colleagues at Bascom Palmer Eye Institute compared a cohort of patients to historical control patients to determine the effect of a modified postkeratoplasty suture removal technique on postop myopia, astigmatism and anisometropia. The authors noted that selective suture removal has previously been shown to reduce astigmatism postop. However, a myopic shift is induced as more interrupted sutures are removed.

In the study, consecutive penetrating keratoplasties using 12 interrupted 10-0 nylon sutures and a 12-bite continuous suture were performed on 92 eyes of 84 patients. An average K reading of 46 D was used to calculate IOL power for eyes undergoing combined PK and IOL exchange.

Patients were followed for an average of 20.7 months. At 6 weeks postop and at the conclusion of suture removal, all patients underwent refraction, keratometry and videokeratoscopy.

A best-corrected visual acuity of 20/50 or better was achieved by 59% of patients.

Prior to suture removal patients had an average spherical equivalent of –0.16 ± 3.59 D. This increased to –1.58 ± 3.66 D at 1 year when suture removal was completed, and to –1.44 ± 3.72 at the last follow-up visit.

At last follow-up, patients had a final refraction of 2.81 ± 1.82 D, a keratometry of 4.19 ± 2.94 and astigmatism of 3.58 ± 2.03 D as assessed by videokeratoscopy. Anisometropia averaged 2.49 ± 2.25 D.

The study is published in the June issue of the American Journal of Ophthalmology.