Penetrating Keratoplasty Performed With Femtosecond Laser Zig-Zag Incision: Suture-Pattern Comparison and Suture-Out Results
Narrative Responses:
Purpose
To report visual and astigmatism outcomes in patients who underwent zig-zag femtosecond laser enabled keratoplasty (FLEK) with subsequent full suture removal. To evaluate the effect of suture pattern on suture-out endpoints.
Methods
Retrospective study at a referral academic practice evaluating uncorrected and corrected distance visual acuity (UDVA, CDVA) as well as manifest (Mrx cyl) and topographical (Topo cyl) astigmatism. 108 eyes underwent suture removal; data are presented for the 84 eyes estimated to have good visual potential (> 20/30). Suture patterns included: running (R) (N=58), interrupted (I) (N=19), combined (C) (N=7).
Results
Full suture removal occurred on average 1.2 years [SD 0.7] after FLEK. The pre vs post suture removal values were significant only for CDVA (showing improvement): UDVA from mean LogMar 0.74[SD 0.45] to 0.68[0.45] (P=0.687), CDVA from 0.28[0.22] to 0.23[0.19] (P=0.024), Mrx cyl from 3.57 [1.83] to 3.48[2.12] (P=0.906) and Topo cyl from 5.33 D[3.83] to 5.71[SD 5.41] (P=0.547). No significant difference were found between the different suture patterns in UDVA (R=0.72[SD 0.47], I=0.82[0.41], C=0.66[0.48]), CDVA (R=0.24[0.18], I=0.41[0.28], C=0.29[0.19]), Mrx cyl (R=3.15[1.76], I=4.58[1.47], C=4.04[2.39]) or Topo cyl (R=4.73[3.82], I=7.18[3.60], C=4.82[3.25]) (P>0.05 for all suture-type comparisons).
Conclusion
The zig-zag FLEK incision results in good vision and astigmatism after suture removal. Suture pattern did not statistically influence final suture-out results although group sizes were asymmetric. Suture pattern analysis is also confounded by non-random assignment (e.g. in neovascular corneas an interrupted pattern was used).