Department of Ophthalmology, Koc University Hospital, Istanbul, Turkey.
Department of Ophthalmology, School of Medicine, Koc University, Istanbul, Turkey.
Arq Bras Oftalmol. 2023 Oct 13;86(5):e20230070. doi: 10.5935/0004-2749.20230070. eCollection 2023.
Postoperative refraction in modern mi-croincision cataract surgery gained extra importance in patients with the previous laser-assisted in situ keratomileusis (LASIK) surgery. The surgically induced astigmatic changes in those eyes may differ not only in magnitude but also in direction compared to virgin corneas. This study aimed to compare the surgically induced astigmatic changes after microscopic cataract surgery between post-LASIK corneas and virgin eyes.
Cases that underwent microincision cataract surgery in eyes with and without previous LASIK surgery were reviewed. The demographics, the axial length at cataract surgery, the central corneal thickness, spheric and cylindric values, keratometry readings, and postoperative posterior corneal astigmatism were retrospectively evaluated. A modified Alpins method was used for astigmatic vector analysis, and baseline astigmatism, surgically induced astigmatism, difference vector, flattening effect, and torque were assessed.
A total of 42 eyes from 24 subjects was evaluated. Group I consisted of 14 eyes with the previous LASIK, and Group II included 28 eyes without any refractive surgery. Preoperative mean central corneal thickness in Group I was significantly thinner (p=0.012). There was no significant difference in baseline astigmatism between the groups regarding magnitude and power vectors. After microincision cataract surgery, there were no significant differences in mean spheric and cylindric values and mean keratometry readings (all p>0.05). However, surgically induced astigmatism and difference vector were significantly higher on J45 vector component in post-LASIK eyes and microincision cataract surgery steepening effect on post-LASIK corneas was significantly higher than those in virgin eyes (p=0.001, p=0.002 and p=0.018, respectively).
Cataract surgery has steepened the corneas in both groups with a significantly higher steepening effect in post-LASIK eyes. Certainly, corneal topography cataract surgery is particularly helpful to provide more precise surgically induced astigmatism interpretations.
在接受过先前激光辅助原位角膜磨镶术（LASIK）的患者中，现代微切口白内障手术的术后屈光至关重要。与正常角膜相比，这些眼的手术诱导的散光变化不仅在幅度上，而且在方向上也可能不同。本研究旨在比较 LASIK 后角膜和正常眼角膜显微镜下白内障手术后手术诱导的散光变化。
回顾性分析了接受微切口白内障手术的 LASIK 前后眼病例。评估了人口统计学数据、白内障手术时的眼轴长度、中央角膜厚度、球镜和柱镜值、角膜曲率读数以及术后后角膜散光。采用改良的 Alpins 方法进行散光向量分析，评估基线散光、手术诱导散光、差异向量、变平效应和扭矩。
共评估了 24 例 42 只眼。第 I 组 14 只眼接受了先前的 LASIK，第 II 组 28 只眼未接受任何屈光手术。第 I 组的术前平均中央角膜厚度明显较薄（p=0.012）。两组之间在大小和力量向量方面的基线散光无显著差异。微切口白内障手术后，平均球镜和柱镜值以及平均角膜曲率读数均无显著差异（均 p>0.05）。然而，LASIK 后 J45 向量分量的手术诱导散光和差异向量明显较高，LASIK 后角膜的微切口白内障手术变陡效应明显高于正常角膜（p=0.001、p=0.002 和 p=0.018）。
白内障手术使两组角膜变陡，LASIK 后变陡效应明显更高。当然，角膜地形图白内障手术特别有助于提供更准确的手术诱导散光解释。
