A new paradigm for corneal wound healing research: The white leghorn chicken (Gallus gallus domesticus)

PURPOSE: To evaluate the chicken cornea as a model for corneal wound healing research. METHODS: We conducted studies on normal chicken corneas and on corneas following mechanical debridement and photorefractive keratectomy (PRK). RESULTS: The chicken cornea possesses six distinct layers that resemble the layers of the human cornea, including a substantial Bowman's layer measuring 5.2 +/- 0.3 microm thick. Reepithelialization time was 44.8 +/- 1.1 hours with a sliding rate of 75.3 +/- 3.2 microm/hour following mechanical debridement and 54.4 +/- 2.8 hours with a sliding rate of 63.3 +/- 3.2 microm/hour for PRK-treated corneas. Biomicroscopic haze post-PRK peaked at 4-6 weeks and regressed until 20 weeks post-PRK. Histologic and clinical observations of wound healing strongly paralleled that noted in humans. CONCLUSION: The chicken cornea's morphology and wound healing response render it a useful model for corneal wound healing investigations.