Salouti Ramin, Nowroozzadeh Mohammad H, Zamani Mohammad, Ghoreyshi Maryam, Salouti Rosa
Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Optometry. 2011 Mar;82(3):140-7. doi: 10.1016/j.optm.2010.07.025. Epub 2010 Oct 8.
The accuracy of biometric measurements, particularly axial length, is critical for precise intraocular lens (IOL) power calculation and predictable refractive outcomes after cataract surgery. Partial coherence interferometry-based systems represent progress toward measurements that are more precise and reliable. The purpose of this study was to evaluate a new noncontact optical biometer (Lenstar; Haag-Streit AG, Koeniz, Switzerland) using optical low-coherence reflectometry and to compare the biometric measurements (including axial length, keratometry, anterior chamber depth, and IOL power) with those obtained from current clinical instrumentation.
Biometric measurements were obtained with Lenstar, IOL Master V.5 (Carl Zeiss Meditec AG, Jena, Germany), and A-scan applanation ultrasound scan combined with a Javal-type keratometer in 234 eyes of 234 subjects scheduled for cataract surgery. IOL power was calculated using Sanders, Retzlaff, Kraff II, Hoffer Q, and Holladay 1 formulas.
The axial length readings were similar (P = 0.997). The anterior chamber depth measurements obtained by IOL Master were slightly smaller than those obtained with other devices (P = 0.092). The means of the average keratometry readings were 0.65 and 0.61 diopters lower when measured with Lenstar as compared with IOL Master and the Javal-type keratometer, respectively (P = 0.002). All of the measurements were tightly correlated (P < 0.001). For anterior chamber depth measurements, however, the correlation was slightly weaker. Using the above-mentioned formulas, the mean IOL power measurements were similar. These measurements were tightly correlated (P < 0.001). The level of agreement was acceptable and comparable between devices.
The findings from this study show the validity and clinical utility of Lenstar compared with instrumentation currently used in clinical practice for assessing ocular biometry and IOL power calculation in cataractous eyes.
生物测量的准确性，尤其是眼轴长度，对于白内障手术后精确的人工晶状体（IOL）度数计算和可预测的屈光结果至关重要。基于部分相干干涉测量法的系统代表了朝着更精确和可靠测量发展的进步。本研究的目的是评估一种使用光学低相干反射测量法的新型非接触式光学生物测量仪（Lenstar；Haag-Streit AG，瑞士科尼茨），并将生物测量结果（包括眼轴长度、角膜曲率、前房深度和IOL度数）与当前临床仪器所获得的结果进行比较。
对计划进行白内障手术的234名受试者的234只眼睛，使用Lenstar、IOL Master V.5（德国耶拿卡尔蔡司医疗技术股份公司）以及A超压平式超声扫描联合Javal型角膜曲率计进行生物测量。使用Sanders、Retzlaff、Kraff II、Hoffer Q和Holladay 1公式计算IOL度数。
眼轴长度读数相似（P = 0.997）。IOL Master测得的前房深度略小于其他设备测得的结果（P = 0.092）。与IOL Master和Javal型角膜曲率计相比，Lenstar测量的平均角膜曲率读数分别低0.65和0.61屈光度（P = 0.002）。所有测量结果均高度相关（P < 0.001）。然而，对于前房深度测量，相关性稍弱。使用上述公式，IOL度数的平均测量结果相似。这些测量结果高度相关（P < 0.001）。各设备之间的一致性水平可接受且具有可比性。
本研究结果表明，与目前临床实践中用于评估白内障眼生物测量和IOL度数计算的仪器相比，Lenstar具有有效性和临床实用性。
