PURPOSE To assess the repeatability of epithelial, stromal, and total corneal thickness measurements with spectral-domain optical coherence tomography (SD-OCT; RTVue-XR; Optovue, Inc., Fremont, CA) in patients with myopia, keratoconus, and corneas after transepithelial photorefractive keratectomy (PRK), small incision lenticule extraction (SMILE), and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). METHODS A total of 352 eyes of 352 patients (75 myopic, 68 post-transepithelial PRK, 61 post-SMILE, 75 post-FS-LASIK, 20 mild keratoconus, and 53 advanced keratoconus eyes) were included. The epithelial, stromal, and total corneal thickness were recorded from the pachymetric map in the following four zones: (1) central 2-mm region, (2) eight paracentral regions within 2- to 5-mm diameter, (3) eight midperipheral regions within 5- to 7-mm diameter, and (4) eight peripheral regions within 7- to 9-mm diameter. Three successive scans were performed to evaluate the repeatability. RESULTS For all zones up to 9-mm diameter, the coefficient of variation (CoV) for epithelial thickness measurements ranged from 1.7% to 3.5% for myopia, 2.6% to 6.2% for post-transepithelial PRK, 2.3% to 4.7% for post-SMILE, 4.0% to 6.3% for post-FS-LASIK, 2.5% to 6.2% for mild keratoconus, and 3.5% to 8.0% for advanced keratoconus. The CoV for stromal and total thickness measurements ranged from 0.2% to 2.0% for myopia, 0.7% to 4.2% for post-transepithelial PRK, 0.3% to 2.4% for post-SMILE, 0.3% to 1.9% for post-FS-LASIK, 0.6% to 3.0% for mild keratoconus, and 1.0% to 5.9% for advanced keratoconus. CONCLUSIONS RTVue-XR SD-OCT showed excellent repeatability when generating the pachymetric map in myopic eyes. Measurements, especially for epithelial thickness, were relatively more variable for corneas with keratoconus and those having undergone keratorefractive surgery. [J Refract Surg. 2019;35(9):600-605.].

中文翻译：

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在异常屈光状态的角膜中使用光学相干断层扫描测量角膜和亚层厚度的可重复性。

目的使用光谱域光学相干断层扫描技术（SD-OCT； RTVue-XR； Optovue，Inc.，加利福尼亚州弗里蒙特），评估近视，圆锥角膜和角膜患者上皮，基质和总角膜厚度测量的可重复性经上皮光折射性角膜切除术（PRK），小切口小孔镜摘除术（SMILE）和飞秒激光辅助原位角膜磨镶术（FS-LASIK）。方法纳入352例患者中的352眼（75例近视，68例经上皮PRK，SMILE术后61例，FS-LASIK术后75例，轻度圆锥角膜和53例晚期圆锥角膜）。从厚度图在以下四个区域记录上皮，间质和总角膜厚度：（1）中心2毫米区域，（2）直径2至5毫米内的八个中央下区域，（3）直径在5到7毫米范围内的八个外围区域，以及（4）直径在7到9毫米范围内的八个外围区域。进行了三个连续扫描以评估可重复性。结果对于所有直径最大为9毫米的区域，上皮厚度测量的变异系数（CoV）在近视范围内为1.7％至3.5％，在上皮后PRK为2.6％至6.2％，对于后上皮PRK为2.3％至4.7％ -SMILE，FS-LASIK后为4.0％至6.3％，轻度圆锥角膜为2.5％至6.2％，晚期圆锥角膜为3.5％至8.0％。近视的基质厚度和总厚度的CoV范围为0.2％至2.0％，经上皮后PRK为0.7％至4.2％，SMILE后为0.3％至2.4％，FS-LASIK后为0.3％至1.9％ ，轻度圆锥角膜为0.6％至3.0％，晚期圆锥角膜为1.0％至5.9％。结论当在近视眼中生成测厚图时，RTVue-XR SD-OCT具有出色的可重复性。对于圆锥角膜和进行了角膜屈光手术的角膜，测量，尤其是上皮厚度的测量，相对变化更大。[J Refract Surg。2019; 35（9）：600-605。]。