Epithelial Healing, Haze, and Optical Outcome With Epi-Bowman Keratome Used for Surface Ablation in Photorefractive Keratectomy
Purpose
To compare the outcome of Epi-Bowman keratome (EBK) with Mechanical Scraper (MS) by quantitatively measuring the optical quality, sub-epithelial haze and epithelial healing in photorefractive keratectomy (PRK).
Methods
A prospective study including fifty eyes of 25 subjects undergoing Photorefractive Keratectomy (PRK) for myopia and myopic astigmatism were randomized into 2 groups. EBK group used Epi-Bowman keratome and MS group used Mechanical Scraper for epithelium debridement of either eye of the same patient. All patients were subjected to optical quality analysis system (OQAS) for modulation transfer function cut off frequency, Strehl ratio and the width of the point-spread function (PSF) to assess the optical quality. Sub-epithelial haze was quantified by densitometry before and after the surgery using scheimpflug imaging. Epithelial mapping was obtained with a spectral-domain OCT to quantitatively assess the epithelial healing in the 2 groups.
Results
EBK Epi-Bowman keratome showed superior results in epithelial healing and optical quality assessment. Our study, clinically documented lesser time for wound healing with EBK, resulting in early subjective patient comfort as compared to MS group using the mechanical scraper. Both groups were safe and comparable in terms of pain and haze formation.
Conclusion
Epi-Bowman keratome revealed better patient comfort with marginally superior optical quality and a lesser wound healing time as compared to a mechanical scraper used for epithelial debridement for surface ablation treatment showing better postoperative outcome.