Effect of central corneal thickness, corneal curvature, and axial length on applanation tonometry
Effect of central corneal thickness, corneal curvature, and axial length on applanation tonometry
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DOI：
10.1001/archopht.124.4.471
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发表时间：
2006-04-01
影响因子：
--
通讯作者：
Pillunat, LE
中科院分区：
文献类型：
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作者：
Kohlhaas, M;Boehm, AG;Pillunat, LE
目的：为了评估中央角膜厚度（CCT），角膜曲率，和轴长压平眼压在体内study.Methods：在一个隐蔽的，前瞻性的临床试验，我们检查了125眼125例白内障手术。角膜曲率测量采用角膜曲率计，眼轴长度测量采用A超。通过在手术前插入前房，在封闭系统中通过水柱将眼内压（IOP）设置为20、35和50 mm Hg。测量厚度后，用压平眼压计测量IOP。Pearson积差相关和多元线性回归分析，配对双尾t检验评价其显著性水平。结果：测量值与真实的IOP之间的差异显著依赖于CCT（P <00 1）。眼压与角膜曲率或眼轴长度之间的相关性无统计学意义（P=. 005）。31）。IOP阅读和CCT之间的关系如“Drescent校正表”所示，该表说明了从550 μ m的CCT每偏离25 μ m，大约需要1 mm Hg的校正。校正值是积极的厚度减少和负的厚度increased.Conclusions：中央角膜厚度显着影响眼压读数根据Goldmann原则通过压平眼压计获得。通过根据Dresstrom校正表考虑CCT来校正IOP读数可能有助于确定准确的IOP值。
Objective: To evaluate the effect of central corneal thickness (CCT), corneal curvature, and axial length on applanation tonometry in an in vivo study.Methods: In a masked, prospective clinical trial, we examined 125 eyes of 125 patients scheduled for cataract surgery. Corneal curvature was measured by means of keratometry and axial length by A-scan ultrasonography. By cannulating the anterior chamber before surgery, intraocular pressure (IOP) was set to 20, 35, and 50 mm Hg in a closed system by means of a water column. After measuring thickness, the IOP was measured with an applanation tonometer. Pearson product moment correlations and multiple linear regression analyses were performed, and significance levels were evaluated by the paired, 2-tailed t test.Results: The difference between measured and real IOP was significantly dependent (P < 001) on CCT. The associations between IOP and corneal curvature or IOP and axial length were not statistically significant (P=. 31). The association between IOP reading and CCT is shown in the "Dresdner correction table," which illustrates an approximately 1-mm Hg correction for every 25-mu m deviation from a CCT of 550 mu m. The correction values were positive as thickness decreased and negative as thickness increased.Conclusions: Central corneal thickness significantly affects IOP readings obtained by applanation tonometry according to the Goldmann principle. A correction of IOP readings by considering CCT according to the Dresdner correction table ight be helpful for determining an accurate IOP value.