Yang Qing-Hua, Chen Bing, Peng Guang-Hua, Li Zhao-Hui, Huang Yi-Fei
Department of Ophthalmology, Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing 100853, China.
Int J Ophthalmol. 2014 Jun 18;7(3):441-5. doi: 10.3980/j.issn.2222-3959.2014.03.10. eCollection 2014.
To evaluate the accuracy of axial length (AL) measurements obtained from immersion B-scan ultrasonography (immersion B-scan) for intraocular lens (IOL) power calculation in patients with high myopia and cataracts.
Immersion B-scan, contact A-scan ultrasonography (contact A-scan), and the IOLMaster were used to preoperatively measure the AL in 102 eyes from 102 patients who underwent phacoemulsification and IOL implantation. Patients were divided into two groups according to the AL: one containing patients with 22 mm≤AL<26 mm(group A) and the other containing patients with AL≥26 mm (group B). The mean error (ME) was calculated from the difference between the AL measurement methods predicted refractive error and the actual postoperative refractive error.
In group A, ALs measured by immersion B-scan (23.48±1.15) didn't differ significantly from those measured by the IOLMaster (23.52±1.17) or from those by contact A-scan (23.38±1.20). In the same group, the standard deviation (SD) of the mean error (ME) of immersion B-scan (-0.090±0.397 D) didn't differ significantly from those of IOLMaster (-0.095±0.411 D) and contact A-scan (-0.099±0.425 D). In group B, ALs measured by immersion B-scan (27.97±2.21 mm) didn't differ significantly from those of the IOLMaster (27.86±2.18 mm), but longer than those measured by Contact A-scan (27.75±2.23 mm, P=0.009). In the same group, the standard deviation (SD) of the mean error (ME) of immersion B-scan (-0.635±0.157 D) didn't differ significantly from those of the IOLMaster (-0.679±0.359 D), but differed significantly from those of contact A-scan (-0.953±1.713 D, P=0.028).
Immersion B-scan exhibits measurement accuracy comparable to that of the IOLMaster, and is thus a good alternative in measuring AL in eyes with high myopia when the IOLMaster can't be used, and it is more accurate than the contact A-scan.
评估在高度近视合并白内障患者中，用于人工晶状体（IOL）屈光度计算的经浸没式B超扫描（浸没式B超）测量眼轴长度（AL）的准确性。
对102例行超声乳化白内障吸除联合IOL植入术的患者的102只眼，术前采用浸没式B超、接触式A超扫描（接触式A超）及IOLMaster测量AL。根据AL将患者分为两组：一组为22mm≤AL<26mm的患者（A组），另一组为AL≥26mm的患者（B组）。根据AL测量方法预测的屈光不正与术后实际屈光不正之间的差异计算平均误差（ME）。
在A组中，浸没式B超测量的AL（23.48±1.15）与IOLMaster测量的（23.52±1.17）以及接触式A超测量的（23.38±1.20）相比，差异无统计学意义。在同一组中，浸没式B超平均误差（ME）的标准差（SD）（-0.090±0.397D）与IOLMaster（-0.095±0.411D）和接触式A超（-0.099±0.425D）相比，差异无统计学意义。在B组中，浸没式B超测量的AL（27.97±2.21mm）与IOLMaster测量的（27.86±2.18mm）相比，差异无统计学意义，但长于接触式A超测量的（27.75±2.23mm，P=0.009）。在同一组中，浸没式B超平均误差（ME）的标准差（SD）（-0.635±0.157D）与IOLMaster（-0.679±0.359D）相比，差异无统计学意义，但与接触式A超（-0.953±1.713D，P=0.028）相比，差异有统计学意义。
浸没式B超显示出与IOLMaster相当的测量准确性，因此在无法使用IOLMaster时，是测量高度近视眼AL的良好替代方法，且比接触式A超更准确。
