ABSTRACT

Purpose: To compare the corneal cone location on different maps and instruments, and their agreements, with elevation maps.Methods: In 90 left eyes with bilateral keratoconus, the apex of cone location was determined based on the maximum simulated keratometry (Kmax) location on the anterior sagittal curvature map by Pentacam HR, the maximum curvature on the mean curvature map by ATLAS 9000, most elevated point of the island of positive elevation relative to the best fit sphere on the front and back corneal elevation maps by Pentacam HR, and thinnest point on the thickness map by Pentacam HR and Orbscan, and the thinnest points on pachymetry and epithelial thickness maps by RTVue OCT.Results: There was a significant difference among the location on different maps along the x- and y-axes (p < .001). The lowest agreement with the cone apex on both front and back elevation maps was for the anterior sagittal curvature map and the highest agreement for the Pentacam thickness map. The majority of keratoconus cone apexes were displaced in the inferotemporal direction on the different maps except for the epithelial thickness maps.Conclusions: Despite the variability between different devices and methods; the thickness map on the Pentacam HR showed the highest correlation with the front and back elevation maps, while the RTVue epithelial thickness map showed the poorest correlation. Based on this study, epithelial thickness maps and anterior curvature maps should be utilized with caution to determine the location of the cone.

摘要

目的：将不同地图和仪器上的角膜锥位置及其协议与高程图进行比较。方法: 90 例双侧圆锥角膜, 根据 Pentacam HR 前矢状面曲率图上的最大模拟角膜曲率 (Kmax) 位置、ATLAS 9000 平均曲率图上的最大曲率、最Pentacam HR 在前后角膜高度图上相对于最佳拟合球体的正高度岛的升高点，Pentacam HR 和 Orbscan 厚度图上的最薄点，以及厚度测量图和上皮厚度图上的最薄点RTVue OCT。结果：沿x轴和y轴在不同地图上的位置存在显着差异（p < .001）。在前后高程图上与锥顶的最低一致性是前矢状曲率图和 Pentacam 厚度图的最高一致性。除上皮厚度图外，大多数圆锥角膜圆锥顶点在不同的地图上沿颞下方向移位。结论：尽管不同设备和方法之间存在差异；Pentacam HR 上的厚度图与前后高程图的相关性最高，而 RTVue 上皮厚度图的相关性最差。根据这项研究，应谨慎使用上皮厚度图和前曲率图来确定锥体的位置。