EXPRESSION OF CELLULAR FIBRONECTIN AND TENASCIN IN THE RABBIT CORNEA AFTER EXCIMER-LASER PHOTOREFRACTIVE KERATECTOMY - A 12-MONTH STUDY

An indirect immunohistochemical technique was used to monitor the expr ession of cellular fibronectin (cFN) and tenascin (TN) in the rabbit c ornea after photorefractive keratectomy (PRK) in a 1 year follow up st udy. 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 epit helial. defects appeared after the primary healing (mean 6.3 (SD 1.2) days). Corneal haze appeared a few weeks after PRK and was observed th roughout the follow up. Three days after wounding an immunoreaction fo r cFN was observed as a bright narrow subepithelial line, but no immun oreaction for TN could be seen in the anterior third of the corneal st roma. 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 mu m. At 12 months, only a trace of cFN immunoreact ion but no TN immunoreaction could be discerned. Our results suggest t hat subepithelial scar tissue contains both cFN and TN up to 12 months .