Expression of cellular fibronectin and tenascin in the rabbit cornea after excimer laser photorefractive keratectomy: A 12 month study

Abstract

An indirect immunohistochemical technique was used to monitor the expression of cellular fibronectin (cFN) and tenascin (TN) in the rabbit cornea after photorefractive keratectomy (PRK) in a 1 year follow up study. Rabbits received a 5.0 D myopic PRK, and were killed 3 days, 1, 3, 6, or 12 months after the operation. In most corneas, secondary epithelial defects appeared after the primary healing (mean 6.3 (SD 1.2) days). Corneal haze appeared a few weeks after PRK and was observed throughout the follow up. Three days after wounding an immunoreaction for cFN was observed as a bright narrow subepithelial line, but no immunoreaction for TN could be seen in the anterior third of the corneal stroma. However, at 1-6 months a similar location of immunoreactions for both cFN and TN was observed. Both were found in the anterior stroma at depths of 30-50 μm. At 12 months, only a trace of cFN immunoreaction but no TN immunoreaction could be discerned. Our results suggest that subepithelial scar tissue contains both cFN and TN up to 12 months.