"MARK A. KONTOS, MD
Although PRK over prior LASIK has advantages, it carries a degree of uncertainty regarding the surgical outcome. Multiple factors probably cause variable outcomes. Mitomycin C (MMC) may have a less predictable effect in this setting, and epithelial hyperplasia is also a significant factor in many of these cases. When I looked through my past cases, I noticed that the patients who had a hyperopic overcorrection tended also to have moderate-to-high myopia at the time of their primary LASIK. The patients who had little or no effect after PRK often had lower myopia at the time of their primary LASIK. I try to keep this in mind when planning treatments. Because of the unpredictable nature of this type of enhancement, a detailed discussion with the patient about all possible outcomes is critical. Sometimes, the best plan of action is to leave things as they are".
As a lay person, I'm wondering if surgeons don't know 100% the expected regrowth of the epithelium, which may also be influenced by the use of Mitomycin C (MMC) as used by the High Street chains, then what the hell is going on, is every Lasek procedure a journey into the unknown?