Femtosecond laser-assisted half-top-hat keratoplasty.

Shaped keratoplasties, such as the top-hat, zigzag, and mushroom keratoplasties, have been reported in the literature to have advantages over traditional penetrating keratoplasty. The manual versions of these techniques have not gained widespread use, most likely because of the difficulty of the surgical technique of manual dissection. Use of a femtosecond laser allows for more consistent results, but this device is not available in the majority of operating theaters worldwide. Here, I describe a modification to the manual half-top-hat technique described by Kaiserman et al that allows for a shaped penetrating keratoplasty without the use of any additional equipment in the operating theater and does not require any additional steps beyond those of traditional penetrating keratoplasty by the operating surgeon.