Effect of femtosecond laser-created clear corneal incision on corneal topography

PURPOSE: To evaluate changes in anterior corneal topography after femtosecond laser-created clear corneal incisions (CCIs). DESIGN: Comparative case series. METHODS: Phacoemulsification was performed through a 2.75 mm incision. In the study group, a 3-plane CCI was created using a 150 kHz femtosecond laser. In the control group, a single-plane angled CCI was created using disposable knives. Placido disk corneal topography was performed preoperatively and 1 week and 1 month postoperatively. Central curvature (simulated keratometry [K]) and local changes in anterior corneal topography at the CCI site were evaluated and compared between groups. RESULTS: No significant changes in the mean simulated K values were found in either group postoperatively (P>.05). The preoperative to 1-month postoperative mean simulated K ranged between 43.30 diopters (D) +/- 0.82 (SD) and 43.17 +/- 0.82 D in the study group and between 43.34 +/- 1.44 D and 43.29 +/- 1.48 D in the control group. The method of CCI creation significantly influenced the changes in the anterior central topography during the first month postoperatively (P<.001). Greater steepening of the incision edges was found in the control group (mean 36.60 +/- 4.13 D to 37.74 +/- 2.39 D) than in the study group (mean 38.81 +/- 2.91 D to 39.15 +/- 4.48 D). CONCLUSIONS: The 2.75 mm 3-plane femtosecond CCIs induced slight changes in the anterior central corneal topography, similar to single-plane angled manual incisions. Topographic differences between the femtosecond method and manual method were found at the CCI site. (C) 2014 ASCRS and ESCRS