Agreement of phakic and pseudophakic anterior chamber depth measurements in IOLMaster and Pentacam
Agreement of phakic and pseudophakic anterior chamber depth measurements in IOLMaster and Pentacam
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IOLMaster 和 Pentacam 中晶状体眼和人工晶状体眼前房深度测量的一致性
DOI：
10.1111/aos.13599
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发表时间：
2018
影响因子：
3.4
通讯作者：
M. la Cour
中科院分区：
文献类型：
--
作者：
Hassan Hamoudi;Ulrik Correll Christensen;M. la Cour
白内障手术中屈光结果的改善主要是由于人工透镜（IOL）屈光度计算公式的准确性和精确的眼部生物测量，包括前房深度（ACD）的测量。每个公式使用特定算法预测有效IOL位置（Olsen 2007）。术后人工晶状体ACD测量可评价该预测的准确性，并可进一步评价不同IOL设计对IOL轴向移动的影响（Luft等，2015）。IOLMaster（Carl Zeiss，Meditec AG，德国）通过狭缝照明和后续图像评价测量ACD。Pentacam（Oculus，韦茨拉尔，德国）使用旋转Scheimpflug相机构建三维图像，并提供ACD和前房体积（ACV）。本研究评估了IOLMaster和Pentacam在有晶状体眼和人工晶状体眼中ACD测量值的一致性，并评估了ACD和ACV之间的相关性。ACD定义为角膜前表面与透镜/IOL前表面之间的距离，这是IOL屈光度计算公式中常用的定义。我们检查了178只眼睛（114只有晶状体眼和64只人工晶状体眼），无角膜混浊、粘连或既往角膜或青光眼手术。人工晶状体眼之前接受了顺利的超声乳化和袋内IOL植入术。在IOLMaster上记录5次测量的平均值，并在Pentacam上选择25张图片设置。在同一天对两个设备依次进行测量，并且由相同的经验丰富的检查员（H.H.）进行所有测量。使用SAS软件（版本9.4; SAS Institute Inc.，卡里，北卡罗来纳州，美国）。平均年龄为69岁，47%为女性。如表1所示，两种器械在测量有晶状体眼的ACD方面具有良好的一致性，器械之间的平均差异为0.03 mm，非常小，无统计学显著性。有晶状体眼的ACD与ACV密切相关。相反，在人工晶状体眼中，两种器械之间的ACD测量值存在高度显著差异，Pentacam测量的ACD平均比IOLMaster长0.53 mm。在人工晶状体眼中，两种器械的标准差更大，ACD-ACV相关性较弱。与依赖于操作员的手持式超声测量不同，Pentacam和IOLMaster均使用光学非接触式方法测量ACD。正确的对准对于避免离轴测量至关重要。在本研究中，我们发现有晶状体眼的ACD测量值相当，这表明从两种器械获得的测量值可以互换（Utine等人，2009）。两种器械都需要从角膜表面和透镜/IOL获得清晰的反射，以确定透镜/IOL前表面的位置。尽管如此，IOL的反射特性可能会干扰该测定，人工晶状体眼中器械之间的不准确性和不一致性可能是由于该测定的困难（Kriechbaum等人，2003）。总之，在有晶状体眼中，IOLMaster和Pentacam之间的ACD测量结果具有良好的一致性。在人工晶状体眼中，ACD测量值不同，且器械之间不可互换。
Editor, T he improved refractive outcome in cataract surgery is mainly due to the accuracy of intraocular lens (IOL) power calculation formulas and precise ocular biometric measurements including measurements of the anterior chamber depth (ACD). Each formula uses a specific algorithm to predict the effective IOL position (Olsen 2007). A postoperative pseudophakic ACD measurement can evaluate the exactness of this prediction and can furthermore evaluate distinct IOL designs impact on axial IOL movements (Luft et al. 2015). The IOLMaster (Carl Zeiss, Meditec AG, Germany) measures the ACD by slit illumination and subsequent image evaluation. The Pentacam (Oculus, Wetzlar, Germany) uses a rotating Scheimpflug camera to construct a three-dimensional image and provides the ACD and the anterior chamber volume (ACV). This study assessed the agreement of ACD measurements between the IOLMaster and the Pentacam in phakic and pseudophakic eyes, and assessed the correlation between the ACD and the ACV. The ACD was defined as the distance between the anterior surface of the cornea and the anterior surface of the lens/IOL, which is the definition usually used in IOL power calculation formulas. We examined 178 eyes (114 phakic and 64 pseudophakic eyes) without corneal opacities, synechiaes, or previous cornea or glaucoma surgery. The pseudophakic eyes had previously undergone uneventful phacoemulsification and in-the-bag IOL implantation. The mean of five measurements was recorded on the IOLMaster, and the 25-picture setting was selected on the Pentacam. Measurements on the two devices were performed sequentially on the same day, and the same experienced examiner (H.H.) performed all measurements. Correlation analysis and paired t-test for each subgroup (phakic and pseudophakic) was conducted using SAS software (release 9.4; SAS Institute Inc., Cary, NC, USA). The mean age was 69 years, and 47% were female. As stated in Table 1, there was good agreement between the two devices in measuring the ACD in phakic eyes, and the mean difference of 0.03 mm between the devices was quite small and not statistically significant. The ACD correlates strongly with the ACV in phakic eyes. In contrary, in pseudophakic eyes, the ACD measurements were highly significantly different between the two devices, and the Pentacam measured the ACD on average 0.53 mm longer than the IOLMaster. The standard deviation was greater in both devices in pseudophakic eyes, and the ACD-ACV correlation was weak. Unlike ultrasound measurement that is operator-dependent and hand-held, both the Pentacam and the IOLMaster use optical noncontact methods to measure the ACD. Correct alignment is crucial to avoid off-axis measurement. In this study, we found that phakic eyes had comparable ACD measurements suggesting that measurements obtained from both devices can be regarded as interchangeable (Utine et al. 2009). Both devices require clear reflections from the corneal surface and the lens/IOL to determine the position of the anterior surface of the lens/IOL. Nonetheless, the reflecting properties of the IOL could interfere with this determination, and the inaccuracy and the disagreement between the devices in pseudophakic eyes may be due to difficulties in this determination (Kriechbaum et al. 2003). In conclusion, in phakic eyes there was good agreement of ACD measurements between the IOLMaster and the Pentacam. In pseudophakic eyes, the ACD measurements were different and not interchangeable between the devices.