Corneal cell response after flap creation using a mechanical microkeratome or a 200 kHz femtosecond laser

To compare the inflammatory cell response within the corneal flap interface created by a mechanical microkeratome and a femtosecond laser.

Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.

Experimental in vitro study.

Corneoscleral buttons of 12 enucleated human eyes not suitable for transplantation were put into organ culture. Corneal flaps were created using a 200 kHz femtosecond laser (Visumax) (femtosecond group) or a mechanical microkeratome (Amadeus) (microkeratome group). Flaps were not lifted after treatment. In 2 corneas, no treatment was performed (control group). Corneas were kept in organ culture for 12 hours thereafter. To evaluate cell-mediated immune reaction, immunofluorescent staining for leucocytes (cluster of differentiation 45) and specifically for dendritic cells (human leukocyte antigen-DR) was performed in every group. A terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was used to determine apoptosis reaction.

The ratio of dendritic cells in the femtosecond group compared with the microkeratome group was 1.2 (P=.02), the ratio of leucocytes was 1.4 (P=.06), and the ratio of apoptotic cells was 1.0 (P=.59). There was no marked significant difference in the distribution of inflammatory cell reaction. The control group showed neither specific inflammatory reaction nor apoptosis.

This in vitro series of human corneas showed similar inflammatory tissue reaction after femtosecond laser-assisted and microkeratome-assisted flap creation (P<.05).

No author has a financial or proprietary interest in any material or method mentioned.