“Groove And Peel” Deep Anterior Lamellar Keratoplasty: How Deep Can You Go?

To measure the thickness of the residual central corneal bed after performing the manual “Groove and Peel” deep anterior lamellar keratoplasty (GP-DALK) technique on human cadaveric eyes.

Wilmer Eye Institute, Johns Hopkins School of Medicine

The manual GP-DALK was performed on six human cadaver eyes by an experienced corneal surgeon. After surgery, the eye globes were fixed in 10% buffered formalin and embedded in paraffin. For each eye, 4-μm-thick hematoxylin and eosin (H&E) sections involving the pupillary axis were obtained and examined. Using an image-processing software, two observers measured the corneal thickness of the residual central corneal bed as well as the host corneal rims adjacent to the area of trephination.

The overall mean central corneal bed thickness was 35.5±12.9 µm, whereas the mean right and left rim thickness were 993.0±141.1 µm and 989.3±147.1 µm, respectively (p=0.0006). In most corneas, the level of dissection reached almost to the pre-Descemetic collagen (Dua’s) layer.

The GP-DALK technique is effective in removing most of the corneal stroma and may be non-inferior to “big-bubble” DALK in some cases.