Corvis ST测量青光眼患者眼压及中央角膜厚度的准确性研究

The Accuracy of Corvis ST for the Measurement of Intraocular Pressure and Central Corneal Thickness in Glaucoma

目的：评估角膜生物力学分析仪（CST）测量青光眼患者眼压（IOP）及中央角膜厚度（CCT）的准确性，研究角膜生物力学参数对IOP的影响。方法：描述性研究。28 例（56 眼）明确诊断为青光眼的患者，由同一位高年资医师分别用CST及Goldmann压平眼压计（GAT）测量其IOP，采用CST和IOLMaster测量CCT。不同设备测量值比较采用配对t 检验，相关性分析采用非参数Spearman检验，一致性验证采用Bland-Altman检验。结果：CST与GAT测得IOP平均值分别为（19.5±12.0）mmHg（1 mmHg=0.133 kPa）、 （20.9±8.8）mmHg，差异无统计学意义；CST与IOLMaster测得CCT平均值分别为（544±40）μm、 （538±40）μm，差异无统计学意义。CST与GAT测得的IOP具有高度相关性（ρ=0.837，P ＜0.001），CST与IOLMaster测得的CCT具有高度相关性（ρ=0.958，P ＜0.001）。GAT与CST测得的IOP差值均值为（1.3±5.4）mmHg，95%的一致性界限为（-9.3,12.0）mmHg，IOLMaster与CST测得的CCT差 值均值为（6±10）μm，95%的一致性界限为（-26,15）μm。结论：CST可获得精确的IOP与CCT，但CST测量的IOP稍低于GAT，在青光眼的诊治中不能完全替代GAT.

Objective： To evaluate the accuracy of intraocular pressure （IOP） and central corneal thickness （CCT） measured by corneal visualization scheimpflug technology （CST）, and to investigate the influence of corneal biomechanical properties on IOP. Methods： For this descriptive study, 28 glaucoma patients （56 eyes） were recruited. An experienced clinician obtained IOP measurements with both the CST and the Goldmann applanation tonometer （GAT）. CCT measurements were obtained with the CST and the IOLMaster. The results of the different devices were compared by paired t-tests. The correlation between IOP measurements by the CST and the GAT and between the CCT measurements by the CST and the IOLMaster were assessed by a nonparametric Spearman test. Device agreement was calculated by Bland-Altman analysis. Results： The mean IOP measured by the CST, 19.5±12.0 mmHg, was not significantly different for that measured by the GAT, 20.9±8.8 mmHg. The mean CCT was 544±40 μm for CST and 538±40 μm for the IOLMaster. Both pairs of devices showed a high correlation for the respective measurements （ρ=0.837, 0.958, both P 〈0.001）. Bland- Altman analysis revealed an IOP bias between the CST and the GAT of 1.3±5.4 mmHg with 95% limits of agreement of -9.3 to 12.0 mmHg. There was also a CCT bias between the CST and the IOLMaster of 6±10 μm,with 95% limits of agreement of -26 to 15 μm. Conclusions： The CST precision is excellent for IOP and CCT measurements. CST can result in a lower IOP measurement than GAT, so these devices may not be interchangeable in the diagnosis and treatment of glaucoma.