Kirgiz Ahmet, Atalay Kurşat, Kaldirim Havva, Cabuk Kubra Serefoglu, Akdemir Mehmet Orcun, Taskapili Muhittin
Eye Clinic, Bagcilar Training and Research Hospital, Istanbul, Turkey.
Department of Ophthalmology, Bulent Ecevit University School of Medicine, Zonguldak, Turkey.
Int Ophthalmol. 2017 Aug;37(4):781-786. doi: 10.1007/s10792-016-0330-4. Epub 2016 Sep 1.
The purpose of this study was to compare the keratometry (K) values obtained by the Scheimpflug camera combined with placido-disk corneal topography (Sirius) and optical biometry (Lenstar) for intraocular lens (IOL) power calculation before the cataract surgery, and to evaluate the accuracy of postoperative refraction. 50 eyes of 40 patients were scheduled to have phacoemulsification with the implantation of a posterior chamber intraocular lens. The IOL power was calculated using the SRK/T formula with Lenstar K and K readings from Sirius. Simulated K (SimK), K at 3-, 5-, and 7-mm zones from Sirius were compared with Lenstar K readings. The accuracy of these parameters was determined by calculating the mean absolute error (MAE). The mean Lenstar K value was 44.05 diopters (D) ±1.93 (SD) and SimK, K at 3-, 5-, and 7-mm zones were 43.85 ± 1.91, 43.88 ± 1.9, 43.84 ± 1.9, 43.66 ± 1.85 D, respectively. There was no statistically significant difference between the K readings (P = 0.901). When Lenstar was used for the corneal power measurements, MAE was 0.42 ± 0.33 D, but when simK of Sirius was used, it was 0.37 ± 0.32 D (the lowest MAE (0.36 ± 0.32 D) was achieved as a result of 5 mm K measurement), but it was not statistically significant (P = 0.892). Of all the K readings of Sirius and Lenstar, Sirius 5-mm zone K readings were the best in predicting a more precise IOL power. The corneal power measurements with the Scheimpflug camera combined with placido-disk corneal topography can be safely used for IOL power calculation.
本研究的目的是比较在白内障手术前,通过结合普拉西多盘角膜地形图的Scheimpflug相机(Sirius)和光学生物测量仪(Lenstar)获得的角膜曲率(K)值,以用于人工晶状体(IOL)屈光力计算,并评估术后屈光的准确性。40例患者的50只眼计划行超声乳化白内障吸除术并植入后房型人工晶状体。使用SRK/T公式,根据Lenstar K值和Sirius的K读数计算IOL屈光力。将Sirius的模拟K值(SimK)、3毫米、5毫米和7毫米区域的K值与Lenstar K读数进行比较。通过计算平均绝对误差(MAE)来确定这些参数的准确性。Lenstar K值的平均值为44.05屈光度(D)±1.93(标准差),SimK、3毫米、5毫米和7毫米区域的K值分别为43.85±1.91、43.88±1.9、43.84±1.9、43.66±1.85 D。K读数之间无统计学显著差异(P = 0.901)。当使用Lenstar进行角膜屈光力测量时,MAE为0.42±0.33 D,但使用Sirius的SimK时,MAE为0.37±0.32 D(5毫米K测量时MAE最低,为0.36±0.32 D),但无统计学显著差异(P = 0.892)。在Sirius和Lenstar的所有K读数中,Sirius 5毫米区域的K读数在预测更精确的IOL屈光力方面表现最佳。结合普拉西多盘角膜地形图的Scheimpflug相机进行角膜屈光力测量可安全地用于IOL屈光力计算。