Corneal epithelial remodeling and its related factors after transepithelial photorefractive keratectomy in treatment of myopia

Abstract

Background Corneal epithelial remodeling will happen after laser refractive surgery, But there have been few studies to evaluate the changes of the corneal epithelial thickness after integrated transepithelial photorefractive keratectomy (TransPRK). Objective This study was to evaluate the changes in epithelial thickness profile within the optical zone and its related factors following TransPRK for myopia. Methods In this retrospective non-randomized controlled study, forty-three patients (43 eyes) who underwent TransPRK with the spherical equivalent refraction -1.25 to -6.25 D from August 2014 to May 2015 in Jinan Mingshui Eye Hospital were included under the informed consent.Epithelial thickness was measured using spectral-domain optical coherence tomography in different corneal zones (central, 2 mm; paracentral, 2-5 mm, and mid-peripheral, 5-6 mm) preoperatively at 1 week and 1, 3, and 6 months postoperatively.Correlations between epithelial thickness changes and the amount of correction, optical zone, and Q-value changes (ΔQ) were analyzed 6 months postoperatively. Results The mean epithelial thickness in the central zone were (53.97±4.33), (51.03±4.11), (55.14±5.46) and (56.68±5.09)μm at 1 week, 1 month, 3 months and 6 months after surgery, respectively.The epithelium were thicker at 3 months and 6 months after surgery compared to preoperative measurements ([52.37±3.42]μm), with significant differences between them (both at P 0.05). Conclusions The epithelial thickness shows a lenticular change with more thickening mid-Peripherally after TransPRK, which results in increased oblateness postoperatively.Epithelial remodeling may modify the profile after surface ablation. Key words: Myopia; Excimer laser; Photorefractive keratectomy; Epithelial thickness; Q value