Yang Qinghua, Chen Bing, Peng Guanghua, Li Zhaohui, Huang Yifei
Department of Ophthalmology, PLA General Hospital,Beijing 100853, China.
Department of Ophthalmology, PLA General Hospital,Beijing 100853, China. Email:
Zhonghua Yan Ke Za Zhi. 2014 Jan;50(1):32-6.
To compare the accuracy of axial length measurement with three methods, that is, immersion B-scan, contact A-scan, and IOLMaster in high myopia with cataract.
To analyze the data of the 40 patients (66 eyes), who were all high myopia with cataract and accepted the phacoemulsification and fold-able lens implantation surgery in our hospital from Jan 2012 to May 2012. The measurement of axial length was performed respectively in 66 eyes by immersion B-scan, contact A-scan and IOLMaster. Keratometric power was measured preoperatively by IOLMaster. The IOL power calculation was carried out according to SRK/T formula in the basis of IOLMaster. Their refraction outcome was follow-up three months after operation.
The axial length was (27.91 ± 1.96) mm, (27.71 ± 2.15) mm, (27.88 ± 2.04) mm respectively by immersion B-scan, A-scan and IOLMaster. There was no significant difference between immersion B-scan and IOLMaster method (t = 0.726, P = 0.473). But the axial length measured by contact A-scan was shorter than that tested by immersion B-scan(t = 2.223, P = 0.003) and IOL Master (t = 2.614, P = 0.014) significantly. There was significant difference between immersion B-scan and contact A-Scan method in those patients whose mean absolute refractive error (MARE) was within ± 0.50 Diopter three months after operation (χ(2) = 5.67, P < 0.05) , while there was no significant difference between immersion B-scan and IOLMaster measurement (χ(2) = 0.06, P > 0.05). The same situation happened in those patients whose MARE was within ± 1.00 Diopter. That means, there was significant difference between immersion B-scan measurement and contact A-scan measurement (χ(2) = 4.19, P < 0.05) , while there was no significant difference between immersion B-scan and IOLMaster measurement(χ(2) = 0.36, P > 0.05).
The immersion B-Scan measurement is better than A-scan, and it is as accurate as the IOL Master measurement, which is another good choice for the axial length measuring in high myopia with cataract cases.
比较三种测量眼轴长度的方法（即浸没式B超、接触式A超和IOLMaster）在高度近视合并白内障患者中的准确性。
分析2012年1月至2012年5月在我院接受白内障超声乳化折叠人工晶状体植入手术的40例（66只眼）高度近视合并白内障患者的数据。分别用浸没式B超、接触式A超和IOLMaster测量66只眼的眼轴长度。术前用IOLMaster测量角膜曲率。根据IOLMaster测量结果，采用SRK/T公式计算人工晶状体度数。术后3个月随访其屈光结果。
浸没式B超、A超和IOLMaster测量的眼轴长度分别为（27.91±1.96）mm、（27.71±2.15）mm、（27.88±2.04）mm。浸没式B超与IOLMaster测量方法之间差异无统计学意义（t = 0.726，P = 0.473）。但接触式A超测量的眼轴长度明显短于浸没式B超（t = 2.223，P = 0.003）和IOLMaster测量的结果（t = 2.614，P = 0.014）。术后3个月平均绝对屈光误差（MARE）在±0.50 D范围内的患者，浸没式B超与接触式A超测量方法之间差异有统计学意义（χ(2)=5.67，P<0.05），而浸没式B超与IOLMaster测量之间差异无统计学意义（χ(2)=0.06，P>0.05）。MARE在±1.00 D范围内的患者情况相同。即浸没式B超测量与接触式A超测量之间差异有统计学意义（χ(2)=4.19，P<0.05），而浸没式B超与IOLMaster测量之间差异无统计学意义（χ(2)=0.36，P>0.05）。
浸没式B超测量优于A超，与IOLMaster测量准确性相当，是高度近视合并白内障患者眼轴长度测量的另一种较好选择。
