Repeat keratoplasty for correction of high or irregular postkeratoplasty astigmatism in clear corneal grafts

Abstract

Purpose: To evaluate the functional results of repeat penetrating keratoplasty in clear corneal grafts with high/irregular postkeratoplasty astigmatism.

Design: Retrospective, longitudinal, single-center, consecutive clinical case series.

Methods: We studied 17 eyes (16 keratoconus, 1 Fuchs' dystrophy) of 16 patients (age, 54.9 +/- 12.6 years). They were treated with repeat PK, performed using the 193-nm Zeiss-Meditec MEL-60 excimer laser using round metal masks (diameter, 7.5-8.0 mm), and employing double running sutures. main outcome measures: Subjective refractometry, standard keratometry, and corneal topography (Tomey TMS-1) were used to assess best-corrected visual acuity (BCVA), spherical equivalent (SEQ), keratometric and topographic central corneal power (CP), refractive, keratometric and topographic astigmatism, surface regularity index (SRI), surface asymmetry index (SAI), and potential visual acuity (PVA) preoperatively, before and after first suture removal (1.1 year), and after second suture removal (1.8 years).

Results: Visual acuity improved significantly (BCVA from 0.2-0.5, P = .04 or better) for all postoperative measurements. CP decreased significantly, but SEQ did not change. All measures of astigmatism and SRI and SAI values showed postoperative improvement with sutures in place; however, astigmatism increased significantly after second suture removal.

Conclusions: With all-sutures-in, BCVA and astigmatism improve significantly after repeat PK for high/irregular astigmatism. However, to present significant increase in astigmatism, final suture removal should be postponed as long as possible in such eyes.