Frozen cultured sheets of epidermal keratinocytes in reepithelialization and repair of the cornea after photorefractive keratectomy

Purpose. To determine whether frozen cultured sheets of human allogeneic epidermal keratinocytes (CEAK) improved wound repair after experimental corneal ablation by photorefractive keratectomy (PRK). Setting. Hospital "Luis Sanchez Bulnes" de la Asociacion para Evitar la Ceguera en Mexico, I.A.P, and Department of Cell Biology, CINVESTAV-IPN, Mexico City, Mexico. Methods: Transepithelial PRK was performed in the right eye of male albino rabbits to obtain a 112 mum deep and 6.0 mm diameter ablation zone. In 17 eyes, the ablations were covered with frozen CEAK; in 11 eyes, the ablations were covered with a disposable contact lens without the cultured sheets; and in the control group (13 eyes), the ablations were not covered. Subepithelial fibrosis and reepithelialization of the ablated zone were evaluated in serial paraffin-em bedded tissue sections from all wounds. Results: Treatment with CEAK reduced fibroblast proliferation and the inflammatory response beneath the ablated zone and produced better organization of the newly formed epithelium by eliminating significant hyperplasia or discontinuities in the periodic acid Shiff-stained basement membrane. It also led to accelerated reepithelialization. Conclusions: The use of frozen CEAK as a biologically active wound dressing improved tissue repair at 1 month in corneas ablated by transepithelial PRK in the male albino rabbit model. Treatment with CEAK could improve the outcome of PRK in humans.