Endothelial cell loss with ultrashort-pulse laser and manually generated full-thickness clear corneal incisions

To compare the extent of corneal endothelial cell loss resulting from creating full-thickness clear corneal incisions manually using a diamond blade with that resulting from use of an ultrashort-pulse laser.

Lensar, Inc., Orlando, Florida, USA.

Experimental study.

Ex vivo porcine globes were randomly assigned to groups for manual or laser-generated full-thickness CCIs. Standard 3-plane manual or laser incisions were made in freshly excised porcine globes. Two laser incision geometries were tested: with the exit incision perpendicular or 45 degrees to the posterior corneal surface. Corneas excised from the globe were measured immediately and after storage for 48 hours in Dulbecco modified Eagle media. Cell loss was assessed by measuring the area of damaged endothelial cells with a fluorescent microscope after cornea staining with a 3-component fluorescent live cell-dead cell assay. The percentage cell loss was expressed as the damaged area divided by the total area of a typical human corneal endothelium.

Endothelial cell losses caused by manual and laser full-thickness CCIs were in the range of 0.8% to 1.4%. Although the mean endothelial cell loss percentages were lower for laser than for manual full-thickness CCIs, the measurements showed no statistically significant differences in the endothelial cell loss percentage between manual full-thickness CCIs and laser full-thickness CCIs with a perpendicular exit incision or 45-degree exit incision geometry.

Ultrashort-pulse laser-generated full-thickness CCIs resulted in the statistically equivalent levels of corneal endothelial cell loss as full-thickness CCIs created by standard manual methods.