IOL Master与接触式A型超声测量白内障患者和正常人前房深度及眼轴长度的比较研究

目的通过比较白内障患者与正常人用两种方法测量的前房深度和眼轴长度值,观察IOL Master和接触式A型超声测量是否存在差别及其关联程度。方法选取2010年12月-2011年2月期间行白内障摘除加人工晶状体植入术的年龄相关性白内障患者及除屈光不正外没有其他眼部病变的志愿者共89例。分别用IOL Maste和A型超声测量54例(96只眼)白内障患者和35例(70只眼)正常者的前房深度(ACD)和眼轴长度(AL),应用配对t检验对每组两种方法测得的ACD及AL值进行比较,并应用Pearson相关分析比较两种方法的相关性。应用独立样本t检验比较白内障组和正常者组间两种方法测得的差值是否不同。结果白内障组A型超声和IOL Master测得的ACD值分别是(2.83±0.34)、(3.05±0.39)mm,AL值分别是(23.93±2.46)、(24.27±2.57)mm,差异均有统计学意义(P<0.05);正常者组A型超声和IOL Master测得的ACD值分别是(3.16±0.36)、(3.43±0.46)mm,AL值分别是(24.16±1.61)、(24.49±1.62)mm,差异均有统计学意义(P<0.05)。两种测量方法的相关系数分别是rACD=0.823(P<0.05)和rAL=0.995(P<0.05)。白内障组和正常者组两种方法测得的ACD差值分别是(0.23±0.23)、(0.28±0.30)mm;AL差值分别是(0.34±0.27)、(0.33±0.15)mm;两组间ACD和AL差值的比较,差异均无统计学意义(P=0.243,0.742)。结论不论是白内障组还是正常者组,用IOL Master测得的ACD及AL值均比A型超声测得的相应值高,但是两种方法测得的值高度相关。白内障组和正常者组用两种方法测得的差值相比无差别;在可测到ACD及AL值的情况下,两种测量方法的差值均不受晶状体密度的影响。

Comparative Study between IOL Master and Contact Ultrasonic A-mode Scan in Measuring Anterior Chamber Depth and Axial Length in Cataract Patients and Normal Subjects

Objective To explore the differences of anterior chamber depth(ACD) and axial length(AL) determined by IOL Master and contact ultrasonic A-mode scan and to evaluate the correlation of the two instruments as well as to compare the spread of the two methods of measuring ACD and AL in cataract patients and normal subjects.Methods Eighty-nine subjects including 54 age-related cataract patients undergoing cataract extraction and intraocular lens implantation between December 2010 and February 2011 and 35 volunteer subjects without ocular diseases except ametropia were included in this study.Ninety-six eyes of 54 cataract patients and 70 eyes of 35 normal subjects were measured first by IOL Master and then by A-mode ultrasonography to obtain ACD and AL values.Paired t test was used to compare the difference of mean ACD and AL of the 2 groups between the two methods and the Pearson’s correlation analysis was used to evaluate the agreement of the two methods.Independent t test was used to compare the spread of the 2 methods between the 2 groups.Results For the cataract group,the mean ACD value was(2.83 ± 0.34) mm for A-mode ultrasonography and(3.05 ± 0.39) mm for IOL Master,and the mean AL value was(23.93 ± 2.46) mm for A-mode ultrasonography and(24.27 ± 2.57) mm for IOL Master,both with statistically significant difference(P < 0.05);for the normal subjects,the mean ACD value was(3.16 ± 0.36) mm for A-mode ultrasonography and(3.43 ± 0.46) mm for IOL Master,and the mean AL value was(24.16 ± 1.61) mm for A-mode ultrasonography and(24.49 ± 1.62) mm for IOL Master,both with statistically significant difference(P < 0.05).The correlation coefficients of the 2 methods werer ACD =0.823(P < 0.05) and r AL =0.995(P < 0.05) respectively.For ACD,the spread of the 2 methods of cataract patients and normal subjects was(0.23 ± 0.23) mm and(0.28 ± 0.30) mm respectively(P=0.243);for AL,the spread of the 2 methods of cataract patients and normal subjects was(0.34 ± 0.27) mm and(0.33 ± 0.15) mm respectively (P=0.243).Conclusions The ACD and AL values measured by IOL Master are longer than those measured by A-mode ultrasonography in both cataract group and normal subjects.But values measured by the two methods are highly correlated.The spread of the two methods has no significant difference,indicating that the lens density doesn’t affect measurements of the two instruments as long as ACD and AL can be detected by IOL Master.