DaVinci® Femtolaser versus Intralase® and Conventional Microkeratoms for Corneal Lamellar Cuts

Abstract

Purpose: : A micromormophological as well as geometrical comparison between Lasik flaps performed with conventional Microkeratomes and the Femtosecond Laser systems DaVinci® Femtolaser and Intralase® are presented. Both Scanning Electron Microscopy and Light Microscopy revealed equal cutting quality of the instruments. There was no difference in the surface smoothness of the stromal bed and the adjacent tissue. The flap edges were better defined and less traumatized with the femtosecond surgical lasers. Lasik conventionally is performed with a mechanical microkeratome. Drawbacks of the method are vision threatening complications of the lamellar cutting part of the procedure. Furthermore it is known that microceratome cuts do vary in flap geometry depending on the size and curvature of the treated cornea. The first femtosecond laser used for the flap cut was introduced with the Intralase and proofed to produce more standardized flap geometries. In this study a new femtosecond surgical laser (DaVinci) was under investigation.

Methods: : The DaVinci femtosecond surgical laser emits infrared laser pulses with nanojoule energy, whereas the Intralase uses microjoule laser pulse energies. The DaVinci femtosecond surgical laser is compact and mobile; it is applied with handheld mirror arm and can easily be applied without the need of changing the position of the patient under the excimer laser. The procedure was performed on ex–vivo pig eyes and human autopsy eyes. We present histopathological sections as well as SEM images and geometrical comparisons.

Results: : The cutting precision of the DaVinci Femtolaser equals the microkeratome inside the stroma. In the comparison of the flap edges the Femtolaser procedures shows its advantages. The edges are smoother and the stroma is not infected with epithelial cells. Compared to Intralase the amount of produced gas bubbles is drastically decreased. The cut is thinner and the flap thickness shows less variations.

Conclusions: : The DaVinci is the latest product in fs–laser–development for ophthalmic surgery. Its advantages are the simple laser concept, the high mobility and its easy handling. It sets a new standard in stability and is as user–friendly as a surgeon can wish. In comparison with the much heavier, bigger and non–mobil Intralase system the DaVinci is a new generation of convenient refractive surgery tools. Its quality has advantages over the mechanical microkeratoms and its safety is outstanding.

Keywords: refractive surgery: LASIK • laser