Li De-jiao, Wang Ning-li, Chen Shu, Li Shu-ning, Mu Da-peng, Wang Tao
Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China.
Chin Med J (Engl). 2009 Apr 20;122(8):955-9.
Phakic intraocular lens (pIOL) implantation has been a popular means for the treatment of high ametropia. Measurements of ciliary sulcus diameter is important for pIOL size determining. But till now, no perfect system can directly measure it. The present study was to evaluate the accuracy, repeatability and reproducibility of direct sulcus diameter measurements obtained by a full-scale 50-megahertz (MHz) ultrasound biomicroscopy (UBM).
A fresh cadaver human eye with a scale marker inserted through the posterior chamber plane from 3 o'clock to 9 o'clock meridian and 30 randomly selected eyes from 30 normal subjects were scanned by full-scale 50-MHz UBM in horizontal meridional scan plane. The distance between the scales and the whole length of the marker inside the cadaver eye were measured by the same observer using the "built-in" measurement tools and the indicating error of instrument was calculated. Reproducibility of the measurement was evaluated in 30 eyes by 2 operators using Blander and Altman plot test. Repeatability was evaluated from 10 successive eyes randomly selected from the 30 eyes by one operator.
On a scale of 1 mm, the greatest indicating error was 40 microm; the mean largest indicating error of 1 mm scale from the 10 images was (26 +/- 14) microm; on a scale of 11 mm, the greatest indicating error was 70 microm; the error rate was 0.64%. The mean length of the needle inside the eye of the 10 images was 11.05 mm, with the mean indicating error of 47 microm, the average error rate was 0.43%. For ciliary sulcus diameter measurements in vivo, the coefficient of variation was 0.38%; the coefficients of repeatability for intra-observer and inter-observer measurements were 1.99% and 2.55%, respectively. The limits of agreement for intra-observer and inter-observer measurement were -0.41 mm to 0.48 mm and -0.59 mm to 0.58 mm, respectively.
The full-scale 50-MHz UBM can be a high accuracy and good repeatability means for direct measuring the ciliary sulcus diameter and useful for size determining of posterior chamber pIOL.
有晶状体眼人工晶状体（pIOL）植入术一直是治疗高度屈光不正的常用方法。测量睫状沟直径对于确定pIOL的尺寸很重要。但到目前为止，尚无完美的系统能够直接测量它。本研究旨在评估通过全量程50兆赫兹（MHz）超声生物显微镜（UBM）获得的直接沟直径测量的准确性、可重复性和再现性。
在水平子午扫描平面上，用全量程50-MHz UBM对一只新鲜尸体人眼进行扫描，该眼从3点至9点子午线穿过后房平面插入一个刻度标记，对30名正常受试者的30只随机选择的眼睛进行扫描。由同一名观察者使用“内置”测量工具测量尸体眼内刻度之间的距离和标记的全长，并计算仪器的指示误差。由2名操作者使用Blander和Altman图测试对30只眼睛的测量再现性进行评估。由一名操作者从30只眼睛中随机选择10只连续的眼睛评估重复性。
在1毫米刻度上，最大指示误差为40微米；10张图像中1毫米刻度的平均最大指示误差为（26±14）微米；在11毫米刻度上，最大指示误差为70微米；误差率为0.64%。10张图像中眼内针的平均长度为11.05毫米，平均指示误差为47微米，平均误差率为0.43%。对于体内睫状沟直径测量，变异系数为0.38%；观察者内和观察者间测量的重复性系数分别为1.99%和2.55%。观察者内和观察者间测量的一致性界限分别为-0.
Zotero 插件