New technique for femtosecond laser creation of clear corneal incisions for cataract surgery

PURPOSE: To evaluate the changes in corneal topography and corneal higher-order wavefront aberrations with the use of a new technique in which clear corneal incisions (CCIs) for cataract surgery are created with a femtosecond laser. SETTING: IRCCS Fondazione G.B. Bietti, Rome, Italy. DESIGN: Prospective randomized case series. METHODS: Cataract surgery patients were randomized into 2 groups. In the study group, a 3-plane CCI was created with a femtosecond laser. In the control group, the single plane-angled CCI was created manually using disposable knives. Simulated keratometry (K) values and corneal higher-order wavefront aberrations with 3.5 mm and 6.0 mm pupils were compared between groups. RESULTS: Each group comprised 10 eyes. At 6 months, the mean change in K values from preoperatively was 0.16 diopter (D) ± 0.14 (SD) in the study group and 0.34 ± 0.16 D in the control group, with no differences between groups (P > .05). The manual CCI significantly increased corneal higher-order wavefront aberrations with 3.5 mm and 6.0 mm pupils (both P < .05). In the study group, corneal higher-order wavefront aberrations increased significantly with a 6.0 mm pupil only (P ≤ .02). The induced changes in corneal higher-order wavefront aberrations were significantly different between groups over both pupil sizes (P < .05). CONCLUSIONS: The femtosecond laser-created CCI did not induce significant changes in simulated K or corneal higher-order wavefront aberrations over the mesopic pupil size. The lower amount of induced corneal higher-order wavefront aberrations with the new technique than with manual CCI could be related to the different geometry of the 2 techniques.