Presence of mitomycin-C in the anterior chamber after photorefractive keratectomy.

PURPOSE: To assess the presence of mitomycin-C (MMC) in hen aqueous humor after photorefractive keratectomy (PRK). SETTING: Instituto Universitario de Oftalmobiología Aplicada, Faculty of Medicine, University of Valladolid, and Department of Analytical Chemistry, Faculty of Sciences, University of Valladolid, Valladolid, Spain. METHODS: Mitomycin-C 0.02% was applied topically for 2 minutes to a right hen's eye after PRK (Group A) and to the left eye with intact epithelium (Group B). At different time points (10, 30, 60, 360, and 720 minutes), aqueous humor was extracted and high-performance liquid chromatography was performed to detect and quantify MMC levels. RESULTS: The mean maximum drug concentration of MMC measured in the aqueous humor was 187.250 microg/L +/- 4.349 (SD) in Group A and 93.000 +/- 4.899 microg/L in Group B, both detected 10 minutes after topical application. Statistically significant differences were found between Groups A and B at 10, 30, and 60 minutes, with decreasing MMC levels in both groups but a higher concentration in Group A. After 360 minutes, MMC levels were undetectable in Group B and after 720 minutes in Group A. CONCLUSIONS: Mitomycin-C was detectable in the aqueous humor of the hen eye after topical application in PRK-treated eyes and in eyes with intact epithelium. The presence of MMC is of concern as it may lead to ocular toxicity in the long term.

Experimental model of laser in situ keratomileusis in hens.

PURPOSE: To develop an experimental animal model of laser in situ keratomileusis (LASIK) in hens. METHODS: One hundred adult hens underwent a 60-microm corneal flap followed by -4 diopter excimer laser ablation. Surgical technique, clinical course, and pathology correlations are presented. RESULTS: Sixty percent of animals had a successful LASIK outcome according to clinical observations. Pathology showed the integrity of Bowman's layer and homogeneous flap in all eyes with good clinical outcomes. Flap complications such as buttonholes (5%), free-flaps (2%), and slipped flaps (3.4%) occurred with the surgical technique. Corneal abscess (2.9%) was also present. Loss of transparency was noted in 26.4%, which correlates with epithelial ingrowth detected by light histology study. CONCLUSIONS: An experimental animal model of LASIK was successfully developed in adult hens. This model could be useful in the study of wound healing and pharmacological modulation after LASIK in an animal with Bowman's layer.