The effect of host rim thickness on the results of selective suture removal during post-operative follow-up of penetrating keratoplasty with large graft diameters

INTRODUCTION: The main goal of this study was to investigate the effect of host rim thickness on the efficacy of selective suture removal (SSR) during postoperative follow-up after penetrating keratoplasty (PK) in patients with large graft diameters.
METHODS: A total of 38 eyes of 38 patients with a graft diameter of 7.75 mm or greater were included in this study. During postoperative follow-up, two sutures were removed in the outpatient clinic from the steep semi-meridians for the management of astigmatism when it was greater than 3.00 D. Manifest refractive cylinder values used to obtain the best-corrected visual acuity (BCVA) were recorded.
RESULTS: The mean age of the patients was 52.66±18.71 years, 58% were male, and 53% underwent surgery on the right eye. The SSR period was 4.30±1.71 (3–11) months postoperatively. The BCVA was 0.20 preoperatively and 0.28 postoperatively on the Snellen scale. The patients were divided into three groups according to rim thickness: <1.81 mm (n=14), 1.81–2.11 mm (n=13), and >2.11 mm (n=11). Following SSR, manifest astigmatism decreased more in eyes with thinner (<1.81 mm) and thicker (>2.11 mm) rims, while the reduction was less pronounced in eyes with rim thickness between 1.81 and 2.11 mm (p<0.001, p<0.001, and p=0.05, respectively).
DISCUSSION AND CONCLUSION: Following SSR in eyes with large grafts, manifest astigmatism decreased more in eyes with thinner (<1.81 mm) and thicker (>2.11 mm) host rims than in those with intermediate rim thickness (1.81–2.11 mm). These findings suggest that host rim thickness may influence the astigmatic response to SSR.

Keywords: Astigmatism, penetrating keratoplasty, suture removal.