Wavefront Properties of the Anterior and Posterior Corneal Surface After Photorefractive Keratectomy
Wavefront Properties of the Anterior and Posterior Corneal Surface After Photorefractive Keratectomy
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DOI：
10.1097/ico.0000000000000035
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发表时间：
2014-02-01
期刊：
影响因子：
2.8
通讯作者：
Nagy, Zoltan Z.
中科院分区：
文献类型：
--
作者：
Juhasz, Eva;Kranitz, Kinga;Nagy, Zoltan Z.
目的：探讨准分子激光屈光性角膜切削术（PRK）术后角膜高阶像差（HOA）的平衡及变化。使用Asclepion Meditec MEL 80 G飞点准分子激光器进行激光扫描。平均消融深度和直径分别为76.78 m（19.40 m）和6.0 mm（0.06 mm）。术前和术后1年分别测定裸眼视力和最佳矫正视力。使用Scheimpflug相机测量前[均方根（RMS）-HOA前]、后（RMS-HOA后）和总角膜（RMS-HOA总）的波前像差。采用分段线性回归分析切削深度与角膜前表面像差的相关性。结果：基线时，RMS-HOA前部显著高于RMS-HOA总（P < 0.001）。手术后，RMS-HOA前向（P < 0.001）和RMS-HOA总值（P < 0.001）显著增加，而RMS-HOA后向值（P = 0.12）保持稳定。消融深度超过76.78 m时，RMS-HOA前部增加2.4倍。未矫正和最佳矫正视力分别为1.0（20/20）的95.5%和98.8%的患者术后1 yearpostoperation.Conclusions：后角膜表面的像差似乎补偿波前改变的前角膜，减少波前误差的量关于近视患者的总角膜。角膜前表面的HOA增加，但后表面保持稳定。在76.78 m光烧蚀深度以上，测量到HOA的增加显著更大。
Purpose:The aim of this study was to evaluate the balance and changes of corneal higher order aberrations (HOAs) after photorefractive keratectomy (PRK).Methods:Myopic and myopic-astigmatic patients (89 eyes of 48 patients) were enrolled in this study. A PRK was performed using an Asclepion Meditec MEL 80 G flying-spot excimer laser. The mean ablation depth and diameter were 76.78 m (19.40 m) and 6.0 mm (0.06 mm), respectively. Before and 1 year after the surgery, uncorrected and best spectacle-corrected visual acuities were determined. Wavefront aberrations of the anterior [root mean square (RMS)-HOA anterior], posterior (RMS-HOA posterior), and total cornea (RMS-HOA total) were measured using a Scheimpflug Camera. Linear piecewise regression analysis was used for correlations between the ablation depth and aberration of the anterior corneal surface. The follow-up time was 1 year.Results:At baseline, RMS-HOA anterior proved to be significantly higher compared with RMS-HOA total (P < 0.001). After the PRK was performed, the RMS-HOA anterior (P < 0.001) and RMS-HOA total values (P < 0.001) increased significantly; however, RMS-HOA posterior values (P = 0.12) remained stable. Above an ablation depth of 76.78 m, the RMS-HOA anterior increased 2.4-fold. Uncorrected and best spectacle-corrected visual acuities were 1.0 (20/20) in 95.5% and 98.8% of the patients 1 year postoperatively.Conclusions:Aberrations of the posterior corneal surface seem to compensate for wavefront alterations of the anterior cornea, decreasing the amount of wavefront error regarding the total cornea in myopic patients. PRK induced increased HOAs with respect to the anterior corneal surface; however, the posterior surface remained stable. The increase in the HOAs was measured to be significantly larger above 76.78 m photoablation depth.