Accuracy of Orbscan optical pachymetry in corneas with haze
Accuracy of Orbscan optical pachymetry in corneas with haze
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DOI：
10.1016/s0886-3350(01)01162-2
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发表时间：
2002-02-01
影响因子：
2.8
通讯作者：
Sborgia, C
中科院分区：
文献类型：
--
作者：
Boscia, F;La Tegola, MG;Sborgia, C
目的：比较Orbscan仪器（Orbtek, Inc.）和超声厚度计（Alcon Surgical）测量角膜厚度的方法。意大利巴里大学眼耳鼻喉科。对6例行2+级雾霾光疗性角膜切除术患者的6只眼，术前、术后分别采用Orbscan光学角膜厚度仪和超声角膜厚度仪进行评估。将同一患者的对侧透明角膜作为对照，每次就诊进行2次Orbscan和5次超声测厚仪测量，记录平均值。评估了测量的准确性和可重复性。结果：术前6只有浑浊的眼，超声测角膜厚度为512.7 mm，光学测角膜厚度为375.0 mm。143.1 ma的平均差异有统计学意义（Wilcoxon sign rank检验，P= 0.0277）。术后中位厚度分别为439.0和433.0 mm；平均差异为10.7妈妈（P= 0.0277）。对照组超声测厚中位数为530.9 μ m，光学测厚中位数为529.0 μ m；平均差异为4.7 μ m （P= 0.1730）。各组精确度均较好；标准偏差小于6.0 m。Orbscan系统显示，当临床上明显的雾霾存在时，测量角膜厚度的准确性下降。测量结果的重复性好，表明误差的原因在于光采集过程。[J]中华白内障杂志；[28] (C) 2002 ASCRS与ESCRS。
Purpose: To compare corneal thickness measurements with the Orbscan instrument (Orbtek, Inc.) and an ultrasonic pachymeter (Alcon Surgical) in comeas with haze.Setting. Department of Ophthalmology and Otolaryngology, University of Bari, Bari, Italy.Methods. Six eyes of 6 patients having phototherapeutic keratectomy for treatment of grade 2+ haze were assessed preoperatively and postoperatively by Orbscan optical pachymetry and ultrasonic pachymetry. Contralateral transparent untreated corneas of the same patients were used as controls, Two Orbscan and 5 ultrasound pachymetry measurements were performed at each visit and the mean values recorded. The accuracy and repeatability of the measurements were evaluated.Results: Preoperatively, the median corneal thickness in the 6 eyes with haze was 512.7 mum by ultrasonic pachymetry and 375.0 mum by optical pachymetry. The mean difference of 143.1 mum was statistically significant (Wilcoxon signed rank test, P=.0277). Postoperatively, the median pachymetry was 439.0 mum and 433.0 mum, respectively; the mean difference was 10.7 mum (P=.0277). In the control group, the median ultrasonic pachymetry was 530.9 mum and the median optical pachymetry, 529.0 mum; the mean difference was 4.7 mum (P=.1730). Precision was good in all groups; the standard deviation was less than 6.0 mum.Conclusions. The Orbscan system showed a decreased accuracy in measuring corneal thickness when clinically significant haze was present. The repeatability of the measures was good, suggesting that the cause of error lies in the optical acquisition process. J Cataract Refract Surg 2002; 28:253-258 (C) 2002 ASCRS and ESCRS.