Topcon KR-1W、iTrace和Topolyzer测量角膜Q值的比较

摘要

Background The measurement of corneal Q value is essential for corneal refractive surgery and calculation of intraocular lens during cataract surgery.Topolyzer was often used for the measurement of Q value,and recently Topcon KR-1W and iTrace were applied in ophthalmology.However,whether the measured values are interchangeable is unclear.Objective This study was to assess the difference and consistency of corneal Q values measured by Topcon KR-1W,iTrace and Topolyzer.Methods Corneal Q values were measured on 100 right eyes of 100 healthy subjects under the approval of Ethic Committee of the Sixth Hospital Affiliated to Shanghai Jiaotong University and informed consent of each subject from November to December in 2014 with Topcon KR-1W,iTrace and Topolyzer.Three valid measurements were obtained for each device,and the average values from each device were calculated.The difference of the outcomes among the instruments was compared by repeated measures analysis of variance (ANOVA),and the consistency among the outcomes from different apparatus was analyzed by Bland-Altman plots.Results The mean corneal Q values were-0.184-±0.112,-0.117±0.167 and-0.269±0.117 from Topcon KR-1W,iTrace and Topolyzer,respectively,with a significant difference among them (P ＜ 0.001).The measured Q value by Topcon KR-1W was 0.085±0.010 larger than that by Topolyzer,and the Q values by iTrace was 0.152± 0.014 larger than that by Topolyzer,while the Q values obtained by Topcon KR-1W was 0.067±0.016 smaller than that by iTrace (all at P＜0.05).The 95％ confidence interval of the values between Topcon KR-1W and iTrace,Topcon KR-1W and Topolyzer,iTrace and Topolyzer were-0.106 to-0.028,0.060 to 0.109 and 0.118 to 0.186,respectively.Bland-Altman plots showed that 6％,6％ and 5％ values were outside of 95％ agreement of limit (LoA) between Topcon KR-1W and iTrace,iTrace and Topolyzer or KR-1W and Topolyzer,respectively,with the maximal differences of 0.28,0.43 and 0.38.Conclusions Corneal Q values measured by Topcon KR-1W and iTrace are larger than those measured by Topolyzer.Due to the poor agreements among the corneal Q values by the 3 kinds of devices,they are not interchangeable in clinical applications for the measurement of corneal Q value.%背景 角膜Q值测量对于角膜屈光手术与白内障术中植入非球面人工晶状体度数的计算至关重要,既往常用的测量仪器为Topolyzer,近年来Topcon KR-1W和iTrace也逐渐用于临床,但三者间测量结果是否可以互相替代尚不清楚. 目的 评估Topcon KR-1W、iTrace和Topolyzer测量角膜Q值的差异性和一致性,为其临床应用提供参考依据.方法 采用前瞻性诊断性试验研究设计,纳入2014年11-12月于上海交通大学附属第六人民医院进行健康体检者100人,受检者平均等效球镜度数为(-3.00±3.15)D,分别用Topcon KR-1W、iTrace和Topolyzer进行角膜Q值测量,每位受检者右眼测得数据纳入分析.采用重复测量的方差分析评估不同仪器测量的角膜Q值的差异;采用Bland-Ahman一致性分析评估不同仪器间测得角膜Q值的一致性. 结果 Topcon KR-1W、iTrace和Topolyzer测得的角膜Q值分别为-0.184±0.112、-0.117±0.167和-0.269±0.117,总体比较差异有统计学意义(P＜0.001);Topcon KR-1W测得的角膜Q值比Topolyzer测得值大0.085±0.010,iTrace测得的角膜Q值比Topolyzer测得值大0.152±0.014,Topcon KR-1W测得的角膜Q值比iTrace小0.067±0.016,差异均有统计学意义(均P＜0.05).Topcon KR-1W与iTrace、Topcon KR-1W与Topolyzer、iTrace与Topolyzer间测得Q值差值的95％可信区间分别为-0.106 ～-0.028、0.060 ～ 0.109和0.118～0.186.Topcon KR-1W与iTrace、iTrace与Topolyzer、KR-1W与Topolyzer测量值间分别有6％、6％和5％的点位于95％一致性界限(LoA)以外,95％LoA内3种仪器测定结果上下限绝对值的最大值分别为0.28、0.43和0.38. 结论 Topcon KR-1W和iTrace测得的角膜Q值均大于Topolyzer测定值,3种仪器测得的角膜Q值一致性欠佳,临床应用时不可相互替代.