In vivo effects of femtosecond laser-assisted keratoplasty

The femtosecond laser is reported to cut lamellar surfaces with varying degrees of smoothness depending on the depth of the cut, with deeper cuts leaving less smooth surfaces. We attempted to evaluate the smoothness of the deeper lamellar surface as cut by the femtosecond laser after allowing 3 months of in vivo healing.

Two patients underwent penetrating keratoplasty 3 months after inadequate visual rehabilitation following femtosecond laser-assisted sutureless anterior lamellar keratoplasty for the treatment of anterior stromal scars. In vivo confocal microscopy that was performed before penetrating keratoplasty demonstrated an acellular zone with a hyperintense signal consistent with a mild interface opacification. Light microscopy in one patient demonstrated scarring limited primarily to the posterior stroma; in the other patient, the interface was smooth with mild scarring of the anterior lamellae. When studied with electron microscopy, the cut surfaces revealed a smooth to very mild stuccolike appearance that was smoother than anticipated.

After 3 months of in vivo healing, the lamellar interface produced by the femtosecond laser, as imaged by electron microscopy, appeared to be nearly smooth with minimal roughness to the cut surfaces. We attribute this to the effects of in vivo healing and remodeling.