Femtosecond laser-assisted intrastromal arcuate keratotomy to reduce corneal astigmatism

Abstract

Purpose: To report the initial results of intrastromal arcuate keratotomy performed with a femtosecond laser to treat corneal astigmatism.

Setting: Department of Ophthalmology, Paracelsus Medical University, Salzburg, Austria.

Design: Interventional case series.

Methods: Patients with corneal astigmatism (naturally occurring or after cataract surgery) were treated with an iFS femtosecond laser to perform paired arcuate cuts on the steep axis completely placed within the corneal stroma. Patients were followed for 6 months after surgery. Preoperative and postoperative (1-day, 1-week, and 1-, 3-, and 6-month) examinations included corrected and uncorrected visual acuities, manifest refraction, corneal topography, endothelial cell count, and corneal pachymetry. A subjective questionnaire was used to evaluate patient satisfaction.

Results: The study enrolled 16 patients. No perforations occurred, and all incisions were placed at the planned locations. After a 6-month follow-up, the mean refractive cylinder was reduced significantly from 1.41 diopters (D) ± 0.66 (SD) to 0.33 ± 0.42 D (P<.001). The mean topographic astigmatism was reduced significantly from 1.50 ± 0.47 D preoperatively to 0.63 ± 0.34 D at 6 months (P=.002). There was excellent refractive and topographic stability over time. The endothelial cell density was unchanged. Patient satisfaction was very high.

Conclusion: The femtosecond laser allowed the effective creation of precise, purely intrastromal, arcuate incision patterns with an excellent safety profile, rapid recovery, and stability of vision without the known risks associated with incisions that penetrate Bowman membrane.