Mechanical Versus Alcohol-assisted Epithelial Debridement During Photorefractive Keratectomy: A Confocal Microscopic Clinical Trial

Journal of Biological Sciences

Volume 12 - Number

Article Type: ---- Unspecified ----

PURPOSE: To compare the effects of mechanical versus alcohol-assisted epithelial debridement on corneal cellular elements after photorefractive keratectomy (PRK) using confocal microscopy. METHODS: This randomized, clinical trial included 66 eyes from 33 patients with spherical equivalent refraction < -4.00 diopters (D). Mechanical versus alcohol-assisted epithelial debridement was performed during PRK. The right eye of each patient was randomly assigned to one group (mechanical group or alcohol-assisted group) and the fellow eye to the alternate group. Confocal examination was performed preoperatively and at 3 and 6 months postoperatively. Main outcome measures were keratocyte density and maximum anterior stromal light reflectivity. RESULTS: Mean epithelial healing time was 3.2 +/- 0.4 and 3.0 +/- 0.3 days in the mechanical and alcohol-assisted groups, respectively (P=.001). Anterior retroablation stromal keratocyte density was 704.3 +/- 119.9 cells/mm(2) and 734.3 +/- 103.7 cells/mm(2) at 3 months (P=.05) and 643.8 +/- 134.4 cells/mm(2) and 696.7 +/- 129.6 cells/mm(2) at 6 months (P=.02) in the mechanical and alcohol-assisted groups, respectively. No significant difference was noted in midstromal and posterior keratocyte density between the two groups. Maximum reflectivity was 61.56 +/- 12.64 international units (IU) and 56.93 +/- 7.86 IU in the mechanical and alcohol-assisted groups, respectively, 3 months after surgery (P=.018). Corresponding values were 49.46 +/- 4.97 IU and 48.98 +/- 4.60 IU, respectively, 6 months after surgery (P=.628). CONCLUSIONS: Due to more adverse effects of mechanical epithelial debridement on anterior keratocyte density and anterior stromal reflectivity, alcohol-assisted epithelial debridement is recommended as the procedure of choice for epithelial removal during PRK in patients with mild myopia. [J Refract Surg. 2011;27(12):887-893.] doi:10.3928/1081597X-20110823-02