Jun Ikhyun, Kang David Sung Yong, Arba-Mosquera Samuel, Kim Eung Kweon, Seo Kyoung Yul, Kim Tae-Im
J Refract Surg. 2018 Aug 1;34(8):533-540. doi: 10.3928/1081597X-20180618-02.
To investigate the clinical outcomes, vector parameters, and corneal aberrations of corneal wavefront-guided (CWFG) transepithelial photorefractive keratectomy (PRK), according to epithelial thickness.
This retrospective, comparative case series study included 91 eyes (91 patients) that underwent CWFG transepithelial PRK for myopic astigmatism. Epithelial thickness was less than 50 μm in 48 patients and 60 μm or greater in 43 patients. Clinical outcomes, including visual acuity, manifest refraction, vector parameters, and corneal wavefront aberration, were compared between the two groups.
The mean uncorrected distance visual acuity, safety and efficacy indices, and aberrometric values were comparable between the two groups at 6 months after transepithelial PRK. The postoperative spherical equivalent was significantly different between the two groups: 0.05 ± 0.19 diopters (D) in the less than 50 μm group and -0.05 ± 0.18 D in the 60 μm or greater group (P = .009). The difference between the two groups was 0.10 D, which is less than the theoretical difference because the epithelial remodeling pattern was different. There was a slight difference in slope between target induced astigmatism vector and surgically induced astigmatism vector (0.9979 in the less than 50 μm group and 0.9145 in the 60 μm or greater group; P = .025).
Transepithelial PRK is an effective and safe treatment modality regardless of epithelial thickness. However, a difference in postoperative refraction is present between the two groups, and astigmatic correction may be less in patients with thick epithelium; hence, a new algorithm is needed that can be tailored in accordance with individual epithelial thickness. [J Refract Surg. 2018;34(8):533-540.].
根据上皮厚度，研究角膜波前引导（CWFG）经上皮屈光性角膜切削术（PRK）的临床结果、矢量参数和角膜像差。
这项回顾性、比较性病例系列研究纳入了91只眼（91例患者），这些患者因近视散光接受了CWFG经上皮PRK手术。48例患者的上皮厚度小于50μm，43例患者的上皮厚度为60μm或更厚。比较两组的临床结果，包括视力、显验光、矢量参数和角膜波前像差。
经上皮PRK术后6个月，两组的平均未矫正远视力、安全性和有效性指标以及像差测量值相当。两组术后等效球镜度有显著差异：上皮厚度小于50μm组为0.05±0.19屈光度（D），上皮厚度60μm或更厚组为-0.05±0.18D（P = .009）。两组之间的差异为0.10D，由于上皮重塑模式不同，该差异小于理论差异。目标诱导散光矢量与手术诱导散光矢量之间的斜率存在轻微差异（上皮厚度小于50μm组为0.9979，上皮厚度60μm或更厚组为0.9145；P = .025）。
无论上皮厚度如何，经上皮PRK都是一种有效且安全的治疗方式。然而，两组术后屈光存在差异，上皮较厚的患者散光矫正可能较差；因此，需要一种新的算法，可根据个体上皮厚度进行调整。[《屈光手术杂志》。2018；34(8):533 - 540。]
