Full-thickness corneal "vent incisions": how deep does the epithelium penetrate?

Objective: To evaluate epithelial cell penetration produced by full-thickness "vent incisions."

Methods: Six donor human corneas with intact epithelium were placed on an artificial anterior chamber. Four perforating paracentral vent incisions were made in each cornea using a diamond knife.

Results: Twenty incisions were analyzed. Of the 20 wounds, 9 (45%) wounds demonstrated introduction of epithelial cells. Of these, 8 (89%) had epithelial cells at the level of the anterior half of the stroma, 3 (33%) had cells at the level of the posterior half of the stroma, and 1 (11%) had cells on the endothelium.

Conclusions: Full-thickness vent incisions, as performed with Descemet stripping automated endothelial keratoplasty, introduced epithelium into the stroma as deep as the endothelium. This may prove a source of epithelial ingrowth.