中央角膜厚度、角膜曲率对Goldmann压平眼压计和非接触眼压计测量结果的影响

目的 探讨中央角膜厚度和角膜曲率对Goldmann压平眼压计(GAT)和非接触眼压计(NCT)测量结果 的影响.方法 比较性研究.选择120例门诊患者作为研究对象.应用超声角膜测厚仪测量患者中央角膜厚度,采用多功能验光仪测量角膜曲率,应用GAT和NCT测量受检者双眼眼压.应用SPSS 12.0统计学软件进行数据处理.采用直线回归法比较两种眼压计的测量结果 ,采用多重线性同归法分析中央角膜厚度、角膜曲率与两种眼压计所测眼压值的关系,应用Bland-Altman法比较NCT和GAT两种方法 对眼压测最结果 的影响.结果 GAT与NCT测量的平均眼压值分别为(18.4±4.0)mm Hg(1 mm Hg=0.133 kPa)和(17.0±4.6)mm Hg,差异有统计学意义(r=0.835,P=0.000).GAT和NCT测量的眼压值均受中央角膜厚度和角膜曲率的影响.中央角膜厚度每增加1μm,GAT测量眼压值增加0.039 mm Hg,而NCT测量眼压值增加0.064 mm Hg.角膜曲率半径每增加1 mm,GAT测最眼压值减少2.648 mm Hg,NCT测量眼压值减少3.190 nun Hg.中央角膜厚度对NCT测量眼压值的影响较其对于GAT测量眼压值的影响大.随着眼压的升高,NCT测最眼压值呈现出由低于GAT测量值到高于GAT测量值的逐渐变化趋势.结论 中央角膜厚度和角膜曲率均会影响NCT和GAT测量眼压值,而且中央角膜厚度对NCT测量眼压值的影响较其对GAT测量眼压值的影响大.

Effects of central corneal thickness and corneal curvature on measurement of intraocular pressure with Goldmann applanation tonometer and non-contact tonometer

Objective To investigate the effects of central corneal thickness (CCT) and corneal curvature (CC) on intraocular pressure (IOP) measurements by the Goldmann applanation tonometer (GAT) and the non-contact tonometer (NCT).Methods One hundred and twenty patients were recruited from the clinic of Peking Union Medical College Hospital.The CCT was measured by ultrasound pachymetry and the mean radius of CC by using Canon PK-5 refractometer.The IOP of each eye was measured by both GAT and NCT. Linear regression was used to compare the measurements of GAT and NCT:multi regression was used to analyze the relationships between CCT,CC and the measurements of GAT and NCT.BlandAhman method was used to compare the effect of NCT and GAT on the IOP measurements.Results The results of the right eyes were reported in this paper.The mean and standard deviation of IOP measured by GAT and NCT was(18.4±4.0)mm Hg(1 mm Hg=0.133 kPa) and (17.0±4.6)mm Hg,respectively,the difference was statistically significant(r=0.835.P:0.000).IOP measured using GAT increased by 0.039 mn Hg per per μm increase in CCT.IOP measured using NCT increased by 0.064 mm Hg per μm increase in CCT.For an increase of 1 mm of mean corneal curvature there was decrease in IOP of 2.648 mm Hg measured by the GAT and of 3.190 mm Hg measured by the NCT.Compared to the GAT,NCT underestimated at low IOP level and overestimated at higher IOP level.Conclusions The IOP measurement obtained with both GAT and NCT varied with CCT and CC.CCT affected IOP measurements by NCT more than that by GAT.