Resumen de Safety and efficacy of Photorefractive Keratectomy (PRK) for myopia using a new corneal epithelium debridement technique
Rafael Bilbao Calabuig, Felix Gonzalez Lopez, Miguel A. Calvo Arrabal, Jose R Villada Casaponsa, J. Beltran-Sanz
PURPOSE: To evaluate the clinical outcomes of photoreactive keratectomy (PRK) for myopia, using a new combined, ethanol-assisted and blunt mechanical corneal epithelial peeling technique.
METHODS: In this prospective cases series, PRK was performed in myopic patients. A circular cellulose cell sponge soaked with 20% ethanol solution was positioned over the central cornea for 50 seconds. The adhesions between the epithelium and corneal stroma were loosened using a Weck-Cel spear, and finally, central loosened corneal epithelium was easily lifted off in a circular epitheliorhexis-like technique. Corneal photoablation was then performed using the usual nomograms and protocols for myopic surface photoablation treatments. Manifest refraction, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity (CDVA) were evaluated preoperatively and postoperatively, and adverse effects were also assessed.
RESULTS: The study enrolled 248 eyes of 144 consecutive patients. Mean and standard deviation of preoperative manifest refraction spherical equivalent (MRSE) was −3.73 ± 1.49 D, and mean preoperative cylinder −0.65 ± 0.71 D. After 6 months, mean decimal UDVA was 0.97 ± 0.08 and MRSE was −0.04 ± 0.33 D; postoperatively 96% of eyes had an MRSE within ±0.50 D of emmetropia. Efficacy Index was 0.99 and Safety Index 1.02. Postoperative mean time for reepithelialization and contact lens removal was 5.1 ± 0.4 days, and no patient required more than 14 days of contact lens wear. No eye lost two or more lines of CDVA, or presented any significant clinical complication. Only one eye required an enhancement procedure.
CONCLUSIONS: This new corneal epithelium debridement technique has been shown to be safe and effective when correcting myopia with PRK.
