A new model for in vitro corneal epithelial wound healing study

A new model for an epithelial wound healing study in pig eyes has been developed in which the excimer laser was used for ablation to create an epithelial wound with precise depth and size. The purpose of this study was to set up an in vitro epithelial wound healing model without photography and defect area measurement. In the study twenty-eight pig eyes received phototherapeutic keratectomy (PTK) with the following diameters: eight at 2.0mm, eight at 1.8 mm, and twelve at 1.5mm. All the wounds were 70 microns in depth. Following PTK, the eyeballs were placed in an incubator, and perfused with TC-199 media by vitreous puncture. TC-199 was then used to rinse eight eyeballs from each group. The remaining four eyes from the 1.5mm group were rinsed with 0.02% Benzalkonium Chloride on an epithelial wound. For the eyes rinsed with TC-199 the average healing time for the 2.0mm group was 31.75 +/- 6.18 hours; the 1.8 mm group was 28.75 +/- 3.85 hours, and the 1.5 mm group was 24.5 +/- 1.77 hours. The corneas rinsed with Benzalkonium Chloride did not heal after 36 hour's observation. Twelve eyeballs without PTK were perfused under the same criteria to evaluate the change of IOP. Following twenty-four hours the IOP range was 15.9 to 20.6mmHg with an average of 19.0mmHg. This study revealed that the healing time decreased as the wound diameter became smaller and the healing was retarded by the drug effect. With this model, the drug influences on corneal epithelial wound healing can be evaluated and the result is revealed in approximately twenty-four hours.