OculyzerⅡ与A型超声测厚仪测量角膜薄点厚度的比较

Comparison of central thinnest corneal thickness measured by Oculyzer Ⅱ and by ultrasonic pachymeter

目的比较Oculyzer II眼前节分析系统和A型超声测厚仪对近视患者中央角膜最薄点厚度(TCT)测量结果的差异性、相关性及一致性,为临床的应用提供理论依据。方法回顾性研究2015年7月在安徽医科大学第一附属医院眼科行准分子近视矫正手术的患者102例(204只眼),利用Oculyzer II及A型超声测量的TCT值,对其进行统计学分析。结果 Oculyzer II测量的左右眼TCT均值分别为(540.43±27.69)μm和(541.54±28.63)μm,差异无统计学意义(t=-0.16,P=0.11);Oculyzer系统和A型超声测量TCT的均值分别为(540.99±28.10)μm和(535.80±29.33)μm,差异具有统计学意义(t=10.595,P=0.000),两者的差值平均为(5.181±6.753)μm,线性相关显示两者具有高度正相关性(r=0.973,P=0.000);96.6%的点落在95%的一致性界限内,表明两法具有较好的一致性,95%的一致性界限为(-8.1μm,18.4μm)。结论 Oculyzer II与A型超声在测量角膜最薄点厚度上虽具有高度的正相关性及一致性但也有显著差异性且95%的一致性界限较宽,临床使用中两者可以相互参考,不能替换。

Objective To explore the agreement in measuring central thinnest corneal thickness（ TCT） between Wave Light Oculyzer II scheimpflug system and ultrasonic pachymeter. Methods This is a retrospective study. TCT was measured in 102 patients（ n = 204 eyes） using Oculyzer II and ultrasonic pachymeter after excimer laser myopia corrective surgery. Data were analyzed using the pared sample t-test,linear correlation and Bland-Altman plots. Results Average TCT of right and left eyes were 540. 43 ± 27. 69 and 541. 54 ± 28. 63 μm measured with Oculyzer II. Average TCT measured with ultrasound pathymeter 540. 99 ± 28. 10 and 535. 80 ± 29. 33 μm. There were statistically significant differences between the two instruments using pared t-test（ t = 10. 595,P〈0. 01）. Sample linear correlation revealed that TCT obtained by Oculyzer II was highly positive correlated（ r = 0. 973,P = 0. 000） with results from ultrasound pachymeter. The Bland-Altman Plots demonstrates relatively good agreement between the two instruments. Conclusions Compared with ultrasonic pachymeter,Oculyzer II showed a high correlation and good consistence in measuring the central thinnest corneal thickness. But there was significant difference. 95% limits of agreements were wide. The two measuring methods were not interchangeable.