Purpose:
To provide an update on evaluating visual outcome as well as astigmatism in patients who had femtosecond laser penetrating keratoplasty performed with a zig-zag incision.
Methods:
Retrospective study at a single center referral academic practice with up to 3-year followup. Candidates for full-thickness penetrating keratoplasty were selected. All cases were performed using the femtosecond laser zigzag pattern and closed with a 24-bite running nylon suture technique. Outcome measures included manifest refractive astigmatism, topographic astigmatism, corrected visual acuity (CVA), and recovery of full visual potential.
Results:
A total of 144 eyes from 129 patients, age 19 to 94 years, were included in this study. Manifest refractive astigmatism remained < 3.62 diopters throughout 3-year followup after post-op month 1, with 2.78 D (SE +/- 0.171) at post-op month 3 and 2.52 D (SE +/- 0.574) at post-op year 2.5. For topographic astigmatism, mean simulated keratometry measurement appeared to plateau starting at 3 months post-operatively (3.31 D, SE +/- 0.292), with 3.86 D (SE +/- 0.86) at post-op month 2.5. CVA continued to improve steadily during 3-year followup, with logMAR 0.347 (SE +/- 0.0245) at post-op month 3, logMAR 0.283 (SE +/- 0.026) at post-op month 9, logMAR 0.298 (SE +/- 0.047) at post-op year 2, and logMAR 0.281 (SE +/- 0.0684) at post-op year 2.5. Patients with potential CVA judged to be better than logMAR 0.30 preoperatively attained CVA of logMAR 0.238 (SE +/- 0.024) at the one-year mark and a CVA of logMAR 0.221 (SE +/- 0.74) at the 2.5 year mark, while patients with potential CVA worse than logMAR 0.30 attained CVA of logMAR 0.561 (SE +/- 0.072) at the one year mark and a CVA of logMAR 0.541 (SE +/- 0.361) at the 2.5 year mark.
Conclusions:
Using the femtosecond laser to generate a zig-zag-shaped incision for corneal transplantation yields consistent results, rapid recovery, relatively low astigmatism, and promising postoperative visual outcome.
Keywords: transplantation • astigmatism • laser