Attachment of cultured corneal epithelial sheets to epikeratophakia lenticules

Tissue lenses for epikeratophakia are currently prepared by one of three different methods: cryolathing and storage in corneal preservation media; cryolathing and lyophilization; or non-freeze microkeratome cutting. It has been proposed that avoidance of the damage caused by freezing or lyophilization will speed healing and recovery of vision. We examined the ability of epithelium to attach to lenses produced in each of the three ways. Human donor corneal epithelium was cultured, and multiple continuous sheets were obtained from each donor eye. Eighteen lenses were prepared by one of the three methods above, and a cultured epithelial sheet was placed on each lens. The percentage of the surface area covered with epithelium and the number of cell layers were determined 24 or 72 hours later. An average of 92% of the lens surface was epithelialized at 24 hours, and 89% was epithelialized at 72 hours. The average number of cell layers was 1.6 at 24 hours and 2.5 at 72 hours, a significant difference. The cryolathed, non-lyophilized lenses showed the lowest percentage of surface area covered, and this was statistically significant at 72 hours.