IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
DIMEC, Ophthalmology Unit, Alma Mater Studiorum Università di Bologna IT, Bologna, Italy.
Int Ophthalmol. 2024 Sep 25;44(1):392. doi: 10.1007/s10792-024-03309-0.
To evaluate and compare the repeatability of corneal densitometry (CD) measurements obtained using both an anterior-segment optical coherence tomography (AS-OCT) device and a Scheimpflug camera system, while also assessing the level of agreement. The study also sought to investigate the correlation of CD with age, gender, and central corneal thickness (CCT) in normal eyes.
CD measurements were obtained using the Casia 2 and the Pentacam AXL Wave. Data were collected on Total Corneal Densitometry and 4 concentric corneal annular areas, these are referred to as zone 1, denoting the central area, through to zone 4, designating the outermost peripheral region. Repeatability was assessed using intra-session test-retest variability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC). The agreement was evaluated using Bland-Altman plots. Correlation analysis was performed between CD, age, gender, and CCT.
The study included 96 healthy volunteers. The Casia 2 demonstrated high repeatability with ICC values exceeding 0.9 in all the corneal zones and lower CoV values compared to the Pentacam AXL Wave (ranging from 1.07% to 2.25% for Casia 2 and from 1.91% to 6.89% for Pentacam).95% LoA were within ± 2 standard deviation from the average mean except from zone 1 (± 2.42).However, the measurements showed a consistent bias among all the corneal zones. CD values were positively correlated with age, except for zone 1 with the Pentacam (p = 0.083).
The findings suggest that the Casia 2 can be a reliable tool for assessing corneal transparency in healthy individuals, however its measurements are not interchangeable with those provided by the Pentacam. The AS-OCT device may be more sensitive in detecting subtle age-related changes in CD within the central zone.
评估和比较使用眼前节光学相干断层扫描（AS-OCT）设备和 Scheimpflug 相机系统获得的角膜密度（CD）测量值的重复性，同时评估一致性水平。该研究还旨在探讨 CD 与正常眼中年龄、性别和中央角膜厚度（CCT）的相关性。
使用 Casia 2 和 Pentacam AXL Wave 进行 CD 测量。收集总角膜密度和 4 个同心角膜环形区域的数据，这些区域分别表示中央区域（第 1 区）到最外层周边区域（第 4 区）。使用内-会话测试-重测变异性、变异系数（CoV）和组内相关系数（ICC）评估重复性。使用 Bland-Altman 图评估一致性。分析 CD、年龄、性别和 CCT 之间的相关性。
该研究纳入了 96 名健康志愿者。Casia 2 在所有角膜区域的 ICC 值均超过 0.9，且 CoV 值低于 Pentacam AXL Wave（Casia 2 为 1.07%-2.25%，Pentacam 为 1.91%-6.89%），除第 1 区外（±2.42），95%的 LoA 在平均均值的±2 个标准差内。然而，所有角膜区域的测量值均显示出一致的偏差。CD 值与年龄呈正相关，但 Pentacam 的第 1 区除外（p=0.083）。
结果表明，Casia 2 可作为评估健康个体角膜透明度的可靠工具，但与 Pentacam 提供的测量值不可互换。AS-OCT 设备在检测中央区域 CD 与年龄相关的细微变化方面可能更为敏感。
