The Effects of Mitomycin C on Tear Function After Photorefractive Keratectomy: A Contralateral Comparative Study
ABSTRACT To assess the effects of adjuvant mitomycin C (MMC) on tear function tests after photorefractive keratectomy (PRK) for myopia.
In this prospective, randomized, double-blind study, one eye of myopic patients undergoing PRK was randomly chosen for PRK and the other eye was treated with PRK plus the application of 0.02% MMC for 20 seconds onto the ablated stroma. All patients had corneal esthesiometry, fluorescein break-up time testing, fluorescein and Rose Bengal staining, and Schirmer testing with anesthesia, and they also completed a questionnaire preoperatively and at 1.5, 3, 6, and 12 months after surgery.
Twenty-seven patients with a mean age of 25 ± 3.27 years were enrolled. There were no statistically significant differences between the PRK and PRK+MMC groups regarding the symptoms and tear function tests preoperatively or at any postoperative follow-up visit. Preoperative and postoperative results in the total sample were also compared; statistically significantly different results were observed in fluorescein break-up time and dry eye symptoms at 1.5 months, which showed improvement thereafter. Corneal sensation was significantly lower at all postoperative follow-up visits compared with preoperative results.
The intraoperative use of MMC during PRK did not induce tear deficiency, and it seems that MMC can be used safely when necessary.[J Refract Surg. 2013;29(4):260-264.].
SourceAvailable from: Javier Tomás-Juan[Show abstract] [Hide abstract]
ABSTRACT: Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final outcome is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain.Journal of Optometry 10/2014; DOI:10.1016/j.optom.