We assessed the impact of sequential double running suture removal on corneal curvature after penetrating keratoplasty (PK), comparing mechanical and nonmechanical excimer laser trephination.Methods:
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).Results:
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).Conclusions:
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.