Varying Effects of Corneal Thickness on Intraocular Pressure Measurements with Different Tonometers
Varying Effects of Corneal Thickness on Intraocular Pressure Measurements with Different Tonometers
复制标题
角膜厚度对不同眼压计测量眼压的不同影响
作者：
Y. Ko;CJ;W. Hsu
目的比较Goldmann压平眼压计(GAT)、非接触眼压计(NCT)和眼血流眼压计(OBFT)对眼压的测量结果，评价不同角膜中央厚度(CCT)对测量结果的影响。以考虑CCT的校正GAT值为标准，通过线性回归模型计算与CCT变量相关的NCT和OBFT测量误差。组间比较采用χ-2检验和单因素方差分析。结果NCT(r=0.872，P<；0.001)和OBFT测量(r=0.861，P<；0.001)与GAT测量高度相关。三种眼压计测量的眼压均与眼压呈正相关(P<；0.001)，其中眼压的回归系数最大(β=0.063，r=0.650)，眼压的回归系数最小(β=0.037，r=0.496)。线性回归模型显示，CCT每改变10μm，NCT测量偏差为0.47~0.98 mm Hg，OBFT测量偏差为0.2 9~0.81 mm Hg。结论GAT、NCT和OBFT压力读数均受CCT的影响，其中NCT影响最大，GAT影响最小。我们的研究结果表明，CCT是解释眼压读数，特别是NCT测量时必须考虑的变量。
AbstractAimsTo compare the intraocular pressure (IOP) measurements using the Goldmann applanation tonometer (GAT), noncontact tonometer (NCT), and ocular blood flow tonometer (OBFT), and to evaluate the effects of varying central corneal thickness (CCT) on the readings.MethodsUltrasound pachymetry and tonometry were performed on 170 eyes. Using the corrected GAT values that took CCT into account as the standard, we calculated the NCT and OBFT measurement errors related to the CCT variable by a linear regression model. Group comparisons were performed with the χ2 test and one-way ANOVA test. The correlation between the various tonometer measurements was analysed by Pearson's correlation method.ResultsBoth the NCT (r=0.872, P<0.001) and OBFT measurements (r=0.861, P<0.001) were highly correlated with the GAT measurements. IOP measurements using the three tonometers were all correlated with CCT (all P<0.001), with the NCT measurements showing the greatest regression coefficient (β=0.063, r=0.650) and the GAT measurements the least (β=0.037, r=0.496). A linear regression model indicated that a 10 μm change in CCT resulted in a NCT measurement deviation of 0.47–0.98 mmHg and an OBFT measurement deviation of 0.29–0.81 mmHg.ConclusionPressure readings with the GAT, NCT, and OBFT are all affected by CCT, with the NCT being the one most affected and the GAT the least. Our findings suggest CCT an essential variable to consider in interpreting IOP readings, especially for the NCT measurements.