Vacuum fixation of corneal lenticules for refractive surgery.

Using the rotating lamellar keratome, a simplified method for nonfreeze shaping of corneal tissue was developed. A set of refractive molding forms was designed for a standardized lenticule diameter. The fixation of the lenticule was achieved by a system of suction holes. A mechanical fixation ring was not required, as the total shearing force exerted by the rotating blade is neutralized even by a low suction setting. Different surface properties (polished, matt, rough) were compared, showing an influence of the surface structure on friction and thus lenticule fixation. With our optimized molding form, the lenticule is safely retained at a suction of 2.5 m H2O.