非接触眼压计测量兔眼压的准确性和可行性

Intraocular pressure measurements with noncontact tonometer in rabbits

目的:探讨非接触眼压计(NCT)测量兔眼压的准确性和可行性。方法:测量兔角膜中央厚度(CCT)、前房插管实际眼压、同步NCT眼压。分析CCT与实际眼压、NCT眼压、NCT眼压误差(实际眼压-NCT眼压)的相关性,分析实际眼压与NCT眼压的差异及相关性,以实际眼压作为应变量进行回归分析。结果:兔CCT与实际眼压、NCT眼压、NCT眼压误差无显著相关(r=0.148,P=0.436;r=0.135,P=0.447;r=0.154,P=0.416)。NCT眼压误差较大(13.24±1.68mmHg),实际眼压与NCT眼压差异有统计学意义(t=43.188,P<0.001);同时实际眼压与NCT眼压有显著相关(r=0.981,P<0.001),筛选回归方程Y=11.278+1.220X,式中Y为实际眼压,X为NCT眼压(回归系数方差分析F=713.521,P<0.001)。结论:NCT测量兔眼压误差较大,必须校正;NCT能够用于测量兔眼压,可借助回归方程通过NCT眼压推断实际眼压。

AIM： To investigate the accuracy and feasibility of intraocular pressure （IOP） measured by noncontact tonometer（NCT） in New Zealand white rabbits. METHODS： The central corneal thickness （CCT） was obtained through ultrasonic pachymeter under topical anesthesia. The actual IOP was measured with a 24G-Y needle inserted into the anterior chamber under general anesthesia, and NCT values were taken simultaneously. The NCT error （actual IOP minus NCT value） was calculated. The relationship between the CCT and actual IOP, NCT value, NCT error was analyzed with Pearson correlation. Readings of the two techniques were compared with paired t-test, and linear regression analysis was performed in these variables. RESULTS. No significant relationship was found between the CCT and actual IOP, NCT value or NCT error （r=0.148, P=0.436; r=0.135, P=0.447; r=0.154, P= 0.416）. NCT values were all obviously lower than actual ones, and the mean NCT error was 13.24 ＋ 1.68mmHg （ Mean ＋ SD）. The readings of two measurements were of statistically significant difference （ t = 43. 188, P 〈 0. 001 ）. A high positive correlation was also found between two measurements （ r = 0. 981, P 〈 0.001 ）. Linear regression analysis showed there was a regression equation for actual IOP, Y= 11. 278 ＋ 1.220X （F= 713. 521, P〈 0. 001 ）, namely, each 0. 820mmHg increase in actual IOP （Y） caused 1 mmHg increase in NCT reading（X）. CONCLUSION.. In this in vivo study, NCT values were all obviously lower than actual ones, but there was also a significant correlation between two measurements. Measuring IOP with NCT is feasible in rabbits, and the regression equation could be used to calibrate the NCT value.