An OCT study showed significant differences in the architecture of clear corneal incisions performed with femtosecond laser vs. a steel bevel knife, mostly in favor of the laser technique.
A study group of 58 eyes of 40 patients underwent femtosecond laser-assisted cataract surgery (FLACS) using the LenSx laser (Alcon Laboratories) to achieve a two-plane CCI with a partial lamellar cut positioned parallel to the collagen lamellae, while a control group of 34 eyes of 26 patients underwent traditional manual CCI using a 2.2-mm single-bevel steel knife (Alcon Laboratories) to perform single oblique plane incisions. All patients received OCT examinations at 1 day, 1 week, 1 month and 3 months postoperatively, using the RTVue-XR Avanti (Optovue) SD-OCT system.
The femtosecond laser group had thinner, less edematous inner and outer incisions, as well as a lower incidence of Descemet’s membrane detachment, possibly attributed to the direction of the femtolaser cut, from the inner to the outer cornea. A lower incidence of posterior wound gape was also noted, for which the authors hypothesized that the partial lamellar cut parallel to the collagen lamellae might improve shearing force effects cross the whole depth of the cornea.
On the other hand, posterior wound retraction, defined as an abrupt recession of the central edge of the posterior wound surface, occurred in a high number of eyes in the femtosecond laser group, namely in 38% of eyes at 1 month and in 50% of eyes at 3 months. No case was noted in control eyes. According to the authors, this might indicate “potential remodeling of the CCI due to molecule dissociation, endothelial cell necrosis, and biomechanical and thermal changes from the femtosecond laser.” – by Michela Cimberle
Wang reports receiving personal fees from Hoya Surgical Optics and Carl Zeiss Meditec, outside the submitted work. Please see the study for the other authors’ relevant financial disclosures.