Ou Tsung-Ho, Lai Ing-Chou, Teng Mei-Ching
Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital, Taiwan.
Chang Gung Med J. 2012 May-Jun;35(3):255-62. doi: 10.4103/2319-4170.106146.
Intraocular pressure (IOP) measurements are affected by the central cornea thickness (CCT). The conventional method for CCT measurement is ultrasonic pachymetry. However, noncontact procedures lower the risk of infection and corneal damage. In this study, we compared the CCT measured by Orbscan II, SP3000P, and ultrasonic pachymetry in patients with glaucoma or glaucoma suspect.
The CCT of 208 eyes (46 eyes with glaucoma suspect, 42 with primary angle-closure glaucoma, and 120 with primary open-angle glaucoma) was measured using Orbscan II, SP3000P, and ultrasonic pachymetry. We compared the linear correlation of the CCT between each mode.
The mean CCT measured by Orbscan II (563.63 ± 35.867 µm) was larger than with the other two devices. There were significant linear correlations between measurements with ultrasonic pachymetry and Orbscan II (Pearson correlation coefficient (r) = 0.793, p < 0.001), ultrasonic pachymetry and SP3000P (r = 0.890, p < 0.001), and Orbscan II and SP3000P (r = 0.803, p < 0.001). We divided the participants into 3 groups on the basis of the CCT measured with ultrasonic pachymetry: ≤ 500 µm, > 500 µm to ≤ 578 µm, and > 578 µm. There was no significant linear correlation between ultrasonic pachymetry and Orbscan II in the thin group. But, in the intermediate and thick CCT groups, there were significant linear correlations between each of the three devices.
We showed good linear correlations of CCT measurements between each of 3 devices, especially in the intermediate and thickest CCTs. These results will be helpful in predicting the relationship between IOP and CCT for the diagnosis and screening of glaucoma; even we used optic systems.
眼压（IOP）测量受中央角膜厚度（CCT）影响。传统的CCT测量方法是超声测厚法。然而，非接触式测量方法可降低感染和角膜损伤风险。在本研究中，我们比较了青光眼或疑似青光眼患者使用Orbscan II、SP3000P测量的CCT与超声测厚法测量结果。
使用Orbscan II、SP3000P和超声测厚法测量208只眼（46只疑似青光眼、42只原发性闭角型青光眼和120只原发性开角型青光眼）的CCT。我们比较了各测量模式之间CCT的线性相关性。
Orbscan II测量的平均CCT（563.63±35.867µm）大于其他两种设备测量的结果。超声测厚法与Orbscan II测量结果之间存在显著线性相关性（Pearson相关系数[r]=0.793，p<0.001），超声测厚法与SP3000P测量结果之间存在显著线性相关性（r=0.890，p<0.001），Orbscan II与SP3000P测量结果之间存在显著线性相关性（r=0.803，p<0.001）。我们根据超声测厚法测量的CCT将参与者分为3组：≤500µm、>500µm至≤578µm和>578µm。在薄组中，超声测厚法与Orbscan II之间无显著线性相关性。但是，在中等厚度和厚CCT组中，三种设备之间均存在显著线性相关性。
我们发现三种设备之间CCT测量结果具有良好的线性相关性，尤其是在中等厚度和最厚的CCT中。这些结果将有助于预测眼压与CCT之间的关系，以用于青光眼的诊断和筛查；即使我们使用的是光学系统。
