Parikh Purak C, Valikodath Nita G, Estopinal Christopher B, Shtein Roni M, Sugar Alan, Niziol Leslie M, Woodward Maria A
Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI.
Cornea. 2017 Apr;36(4):419-424. doi: 10.1097/ICO.0000000000001148.
To ensure optimal care of patients, cornea specialists measure corneal features, including epithelial defects (ED), with slit-lamp calipers. However, caliper measurements are subject to interphysician variability. We examined the extent of variability in ED measurements between cornea specialists and discuss the potential clinical impact.
A total of 48 variably sized EDs were created in pig eyes. Three cornea specialists measured the maximum vertical and horizontal ED lengths to the nearest 10th of a millimeter using slit-lamp microscopy. An absolute difference in ED measurement between cornea specialists of 0.5 mm was chosen to be the a priori threshold for clinical significance and was evaluated by the Wilcoxon signed-rank test. Interrater reliability was assessed by intraclass correlation coefficients.
The average absolute difference in the vertical ED length between pairs of examiners ranged from 0.54 to 0.63 mm, and that of the horizontal ED length ranged from 0.44 to 0.46 mm. These differences in ED measurement were not significantly different from 0.5 mm (all P > 0.06). However, pairs of examiners differed in vertical ED length measurements by >0.5 mm in 44% to 52% of EDs and by >1.0 mm in 13% to 17% of EDs. Pairs of examiners differed in horizontal ED length measurements by >0.5 mm in 31% to 40% of EDs and by >1.0 mm in 10% to 15% of EDs. The intraclass correlation coefficient was 0.85 (95% confidence interval, 0.77-0.91) for vertical and 0.84 (95% confidence interval, 0.74-0.90) for horizontal ED measurements.
Cornea specialists showed good reliability in the measured EDs; however, depending on the threshold for clinical significance, a nontrivial percentage of cases have high interexaminer clinical variability.
为确保对患者的最佳护理，角膜专科医生使用裂隙灯卡尺测量角膜特征，包括上皮缺损（ED）。然而，卡尺测量存在医生间的差异。我们研究了角膜专科医生之间ED测量的差异程度，并讨论了潜在的临床影响。
在猪眼上制造了总共48个大小各异的ED。三名角膜专科医生使用裂隙灯显微镜测量最大垂直和水平ED长度，精确到十分之一毫米。将角膜专科医生之间ED测量的绝对差异0.5毫米选为具有临床意义的先验阈值，并通过Wilcoxon符号秩检验进行评估。通过组内相关系数评估评分者间的可靠性。
检查者对之间垂直ED长度的平均绝对差异在0.54至0.63毫米之间，水平ED长度的平均绝对差异在0.44至0.46毫米之间。这些ED测量差异与0.5毫米无显著差异（所有P>0.06）。然而，在44%至52%的ED中，检查者对之间垂直ED长度测量的差异>0.5毫米，在13%至17%的ED中差异>1.0毫米。在31%至40%的ED中，检查者对之间水平ED长度测量的差异>0.5毫米，在10%至15%的ED中差异>1.0毫米。垂直ED测量的组内相关系数为0.85（95%置信区间，0.77 - 0.91），水平ED测量的组内相关系数为0.84（95%置信区间，0.74 - 0.90）。
角膜专科医生在测量的ED方面显示出良好的可靠性；然而，根据临床意义的阈值，相当比例的病例存在较高的检查者间临床变异性。
