Reconsidering Sequential Double Running Suture Removal After Penetrating Keratoplasty: A Prospective Randomized Study Comparing Excimer Laser and Motor Trephination.

Abstract

We assessed the impact of sequential double running suture removal on corneal curvature after penetrating keratoplasty (PK), comparing mechanical and nonmechanical excimer laser trephination. PK was performed in 134 patients (mean age 51 ± 18 yrs) using either the excimer laser [excimer, n = 60 (37 keratoconus and 23 Fuchs dystrophy)] or motor trephination [control, n = 74 (44 keratoconus and 30 Fuchs dystrophy)] and a double running cross-stitch suture. Refractometry, Zeiss keratometry, and Tomey corneal topography were performed before removal of the first suture (15.2 ± 4.2 mo) and immediately before and at least 6 weeks after removal of the second suture (21.4 ± 5.6 mo). Keratometry before removal of the first (-1.7 ± 2.3 D vs. -3.1 ± 2.8 D) and second (-2.3 ± 2.6 D vs. -3.8 ± 2.8 D) sutures showed that the change in the corneal base curve was significantly smaller in the excimer group than the control group (P < 0.004). After complete suture removal, astigmatism decreased in 52% and 11%, remained stable (±0.5 D) in 27% and 9%, and increased in 21% and 80% of eyes in the excimer and control groups, respectively, resulting in significantly lower astigmatism in the excimer (3.1 ± 2.1 D) group compared with the control group (6.2 ± 2.9 D) with "all-sutures-out" (P < 0.0001). The change in vector-corrected astigmatism (Jaffe) was significantly smaller in the excimer group (4.3 ± 3.5 D) than in the control group (6.9 ± 4.5 D; P < 0.001). In conclusion, less change in astigmatism and the base curve after sequential removal of a double running suture indicates better alignment of the graft in the recipient bed after excimer laser trephination. After double running suture removal, astigmatism decreases or remains unchanged in 79% of patients after excimer laser keratoplasty and increases in 80% of patients after conventional motor trephination.