Eye Center, the Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, 310000, Zhejiang, China.
Department of Ophthalmology, Shanxi Provincial Cancer Hospital, Affiliated Cancer Hospital of Shanxi Medical University, Taiyuan, China.
BMC Ophthalmol. 2020 May 6;20(1):187. doi: 10.1186/s12886-020-01456-3.
In the present study, we aimed to analyze the effects of cataract surgery using a 1.8-mm steep-axis clear corneal incision (CCI) on the posterior corneal surfaces based on the keratometry from the rotating Scheimpflug imaging device (Pentacam HR) in candidates for toric intraocular lens (IOL) implantation.
Preoperative and at least 1-month postoperative data measured by Pentacam HR were collected in patients for toric IOL implantation. Surgically induced astigmatism on the posterior cornea (P-SIA) was calculated based on the preoperative and postoperative keratometric data, and the related factors of P-SIA were analyzed.
A total of 60 eyes from 56 patients were enrolled. The preoperative anterior, posterior and total corneal astigmatism was 1.58 ± 0.61 D,0.28 ± 0.22 D and 1.70 ± 0.52 D respectively. The postoperative anterior, posterior and total corneal astigmatism was 1.26 ± 0.68 D, 0.41 ± 0.26 D and 1.30 ± 0.51 D respectively. The astigmatism was significantly decreased on anterior surface (P<0.001, paired t-test) and increased on posterior surface (P<0.001, paired t-test). The mean of P-SIA calculated by Holladay-Cravy-Koch method was 0.34 ± 0.20 D, with 0.5 D or greater accounting for 26.7%. A statistically significant correlation was observed between the P-SIA and preoperative anterior corneal astigmatism (r = 0.29, P = 0.024), as well as preoperative posterior corneal astigmatism (r = 0.27, P = 0.038). Multivariate regression analysis showed the preoperative anterior and posterior corneal astigmatism had a significant effect on P-SIA (F = 7.344, P = 0.001).
In candidates for toric IOL implantation with a 1.8-mm steep-axis CCI, the incision caused a significant reduction of the anterior corneal astigmatism but an increase of the posterior corneal astigmatism. P-SIA could not be ignored, and it played a significant role in SIA, especially in cases with higher preoperative anterior or posterior corneal astigmatism.
本研究旨在分析在拟行散光矫正型人工晶状体（toric IOL）植入术的患者中，使用 1.8mm 陡峭轴透明角膜切口（CCI）对角膜后表面的影响，该方法基于旋转Scheimpflug 成像设备（Pentacam HR）的角膜曲率计测量值。
收集拟行 toric IOL 植入术患者的术前和至少术后 1 个月的 Pentacam HR 测量数据。根据术前和术后的角膜曲率计数据计算角膜后表面手术诱导散光（P-SIA），并分析 P-SIA 的相关因素。
共纳入 56 例 60 只眼。术前前、后和总角膜散光分别为 1.58±0.61D、0.28±0.22D 和 1.70±0.52D。术后前、后和总角膜散光分别为 1.26±0.68D、0.41±0.26D 和 1.30±0.51D。前表面散光明显降低（P<0.001，配对 t 检验），后表面散光明显增加（P<0.001，配对 t 检验）。Holladay-Cravy-Koch 法计算的 P-SIA 平均值为 0.34±0.20D，0.5D 或更大占 26.7%。P-SIA 与术前前角膜散光（r=0.29，P=0.024）和术前后角膜散光（r=0.27，P=0.038）呈显著相关。多变量回归分析显示，术前前、后角膜散光对 P-SIA 有显著影响（F=7.344，P=0.001）。
在拟行 1.8mm 陡峭轴 CCI 的 toric IOL 植入术患者中，切口导致前角膜散光明显减少，但后角膜散光增加。P-SIA 不容忽视，它在散光中起着重要作用，尤其是在前或后角膜散光较高的情况下。
