Abstract
Purpose:
To compare postoperative outcomes of femtosecond (FS) laser-assisted with conventional trephine (CN) deep anterior lamellar keratoplasty (DALK) for keratoconus.
Methods:
A prospective comparison of a consecutive 8 eyes that underwent FS laser zigzag incision DALK versus 26 eyes that underwent conventional Barron suction trephination DALK. All DALKs were closed with an identical 16-bite interrupted nylon suture technique.
Results:
Median follow-up was 29 (range 23-31) months and 25 (range 23-33) months in the FS and CN groups, respectively. Mean keratometry decreased following DALK from 59.14±3.5 to 46.64±4.6D and from 52.89±1.6 to 43.35±4.9D in the FS and CN groups, respectively. There was no statistical significance (p>0.05) in postoperative mean keratometry power between two groups. Median preoperative Snellen best corrected visual acuity (BCVA) was 20/60 in two groups. Median postoperative BCVA was 20/40 and 20/30 for the FS and CN groups, respectively (p>0.05). Mean graft sizes were statistically different at 8.27±0.016mm and 7.85±0.42mm in FS and CN groups, respectively (p=0.005).The rate of complications were similar between two groups (p>0.05).
Conclusions:
Final BCVA, astigmatism and complications did not differ between the FS laser-assisted and CN DALK. However, the FS laser-generated zigzag incision was biomechanically stable, resulting in earlier suture removal, more reduction of steeper corneas, and recovery of good levels of BCVA with moderate astigmatism within months of surgery. Graft size was larger and more predictable with the FS-DLKP. Larger sample size may be needed to address any limitations in this study.