"Top hat"-shaped penetrating keratoplasty using the femtosecond laser.

Abstract

To determine the feasibility of using a modified femtosecond laser to perform penetrating corneal resections. Controlled laboratory study. Fourteen corneoscleral rims were mounted on an artificial anterior chamber. Eight underwent traditional penetrating keratoplasty (PKP) and six underwent "top hat"-shaped PKP using a femtosecond laser. Wound leakage pressure and induced astigmatism were compared between the two groups. Deep corneal resection with the femtosecond laser was feasible. Wound leakage occurred at 38 +/- 11 mm Hg in the traditional PKP eyes and at 240 +/- 69 mm Hg in the laser-shaped PKP groups. Initial induced astigmatism was 3.76 +/- 0.82 diopters and 3.46 +/- 1.36 diopters in the traditional and shaped PKP groups, respectively. Shaped PKP using the femtosecond laser is feasible and provides superior incision integrity compared to traditional PKP. Initial induced astigmatism is dominated by suture effects.