The use of confocal microscopy in evaluating corneal wound healing after excimer laser keratectomy

Corneal wound healing following excimer laser keratectomy is the major cause of regression of treatment results. The amount of anterior stromal haze that develops may be influenced by topical medications. Over a period of 6 months, we followed 15 New Zealand white rabbit eyes that underwent excimer laser keratectomy with the VISX 193-nm ArF laser at a fluence of 150 mJ/cm2 for a depth of 130 microns. Eyes were randomized to treatment with prednisolone acetate, diclofenac sodium (Voltaren), a combination of both, and a control group. Drops were administered four times a day for 1 week, two times a day for 3 weeks, and the drops were then tapered. All eyes were reepithelialized by 5 to 7 days. The tandem scanning confocal microscope (TSCM) was used to evaluate the corneal wound in vivo weekly for a month and monthly for 6 months. During the early postoperative period, the TSCM revealed significant anterior stromal keratocyte activation with cell elongation and the spindle-shaped appearance of fibroblasts in all groups. Collagenous stromal scarring was evident initially, then slowly decreased in all treatment groups. This study shows that TSCM is clinically useful for successive in vivo examinations of corneal wounds after excimer laser keratectomy and for comparing the effects of various topical medications.