Long term follow of PRK with inraoperative Mitomycin-C – Updated cofocal microscopic examination results

Purpose: To evaluate the safety and efficacy of Mitomycin-C (MMC) during photorefractive keratectomy (PRK). Method: 115 eyes of 59 patients were enrolled in this study. Patients had PRK with intraoperative MMC for 30 seconds to 2 minutes. Patients were followed up for 5 years (5 ˜ 6yrs). Visual acuity, refractive error and corneal haze were measured. Confocal microscopic examinations were done at 1 and 5 postoperative years. Corneal endothelial counts and keratocyte population were measured. Results: 76% of eyes were within 0.5 D and 66% of eyes showed more than 20/20. Only 3% of eyes lost 1 line of vision but there were no eyes that lost 2 or more lines. Corneal hazes happen in 6 eyes. 5 of them showed grade 1 and one eye was grade2. Corneal endothelial cell counts were not different at 1 and 5 year compared to normal control. At 1 year, keratocyte density decreased significantly at superficial layer only. But at 5 years, they were significant decrease at all corneal stromal layers. There was no other severe complication related to MMC toxicity. Conclusion: MMC is a safe and effective method to prevent corneal haze.