*Department of Ophthalmology, Hando Hospital, Ansan, Korea; †Department of Ophthalmology, Soonchunhyang University Hospital, Bucheon, Korea; ‡Ian Eye Center, Seoul, Korea; §Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea; and ¶Corneal Dystrophy Research Institute, Severance Biomedical Science Institute, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
Cornea. 2014 Feb;33(2):148-53. doi: 10.1097/ICO.0000000000000036.
The aim of this study was to predict the mean corneal power change preoperatively for simultaneous pterygium excision and cataract extraction.
This study was performed in 2 stages. First, 66 eyes undergoing pterygium excision were recruited, and the subjects were divided into 2 groups based on a pterygium length of 2.0 mm (group 1: <2.0 mm, group 2: ≥2.0 mm). Keratometric values (K) were measured before, 1 month after, and 3 months after surgery. Multiple regression analyses were used to predict the postoperative mean K using preoperative K and morphological factors that significantly affect corneal power change. In the second stage, the regression equation was applied to 50 eyes (23 with pterygium <2.0 mm and 27 with pterygium ≥2.0 mm) in several clinics. Prediction accuracy was graded based on the difference between the calculated mean K and the postoperative mean K.
In group 1, the mean Ks did not change significantly after the surgery, and therefore, the predicted mean K was not statistically different from the preoperative mean K. In group 2, the horizontal and mean Ks steepened significantly, and the regression analysis predicted the mean K within the range of 0.5 diopter difference in 22 of 31 eyes, showing a better approximation compared with the preoperative mean K (P < 0.001). The prediction accuracy was verified similarly in other clinics, and the regression analysis was useful for pterygium exceeding a length of 2.0 mm.
Pterygium exceeding a length of 2.0 mm induced a significant corneal power change after surgery. The mean K predicted from the regression analysis could be used as an approximation for a simultaneous pterygium and cataract surgery.
本研究旨在预测同时行翼状胬肉切除术和白内障摘出术后平均角膜曲率的变化。
本研究分两个阶段进行。首先，招募了 66 例行翼状胬肉切除术的患者，根据翼状胬肉的长度将患者分为 2 组，长度为 2.0mm（组 1：<2.0mm，组 2：≥2.0mm）。术前、术后 1 个月和 3 个月测量角膜曲率值（K）。采用多元回归分析，使用术前 K 值和对角膜曲率变化有显著影响的形态学因素预测术后平均 K 值。在第二阶段，将回归方程应用于 50 只眼（组 1：23 只翼状胬肉<2.0mm，组 2：27 只翼状胬肉≥2.0mm）在几个诊所。根据计算的平均 K 值与术后平均 K 值的差异对预测准确性进行分级。
在组 1 中，术后平均 K 值没有明显变化，因此，预测的平均 K 值与术前平均 K 值没有统计学差异。在组 2 中，水平和平均 K 值明显变陡，回归分析预测 31 只眼中有 22 只的平均 K 值在 0.5 屈光度差异范围内，与术前平均 K 值更接近（P<0.001）。在其他诊所也得到了类似的验证，回归分析对于翼状胬肉长度超过 2.0mm 的情况是有用的。
翼状胬肉长度超过 2.0mm 术后会引起明显的角膜曲率变化。回归分析预测的平均 K 值可作为同时行翼状胬肉和白内障手术的近似值。
