Bergmann Benjamin, Wolffsohn James S, Bandlitz Stefan
Höhere Fachschule für Augenoptik Köln, Cologne School of Optometry, Cologne, Germany.
School of Health and Life Sciences, Aston University, Birmingham, United Kingdom.
Cont Lens Anterior Eye. 2023 Apr;46(2):101753. doi: 10.1016/j.clae.2022.101753. Epub 2022 Aug 24.
The corneo-scleral-profile (CSP) describes the transition from cornea to sclera, while the corneo-scleral junction angle (CSJ), is the angle formed between the cornea and the sclera. The aims of this study were (i) to analyse the CSP and CSJ in different quadrants and (ii) to test correlation and repeatability of an established observational grading and measurement method, using Scheimpflug images.
The nasal, temporal, superior and inferior CSP of 35 healthy eye participants (mean age 25.5 SD ± 3.1 years; 20 female) was imaged using the corneo-scleral-profile module of the Pentacam (Oculus, Wetzlar, Germany). On the captured Scheimpflug images CSP was subjectively graded into five different corneo-scleral transitions, using the Meier grading scale (profile 1 fluid-convex; profile 2 fluid-tangential; profile 3 marked-convex; profile 4 marked-tangential; profile 5 concave). The CSJ was measured on the same images using ImageJ v1.8.0. Grading and measurement was repeated at a second session. Intra-observer reliability for the CSP-grading was analysed by Cohen's Kappa. Differences between repeated CSJ-measurements and different quadrants were analysed by paired-t-test and ANOVA. The eta-coefficient was used to determine the association between subjective CSP-grading and CSJ-measurement.
Intra-observer reliability for the CSP grading system was poor (kappa = 0.098) whereas repeated measurements of CSJ angle showed no statistically significant difference between sessions (0.04°; 95 % CI - 0.21° to 0.29°; p = 0.77). CSJ angles ranged from 172° to 180° with no statistically significant differences between nasal, temporal, superior and inferior (p = 0.24). Eta-coefficient indicated a weak association between CSP-grading and CSJ-measurement (η = 0.27; p = 0.04).
The subjective CSP-grading showed poorer repeatability than the objective CSJ-measurement, which did not detect any differences in angles between the meridians. The weak association between CSP-grading and CSJ-measurement is likely caused by the limited intra-observer reliability of the Meier grading scale. Furthermore, the CSP-grading scale seems to consider other aspects beside the CSJ angle, such as scleral radius.
角膜-巩膜轮廓（CSP）描述了从角膜到巩膜的过渡，而角膜-巩膜交界角（CSJ）是角膜与巩膜之间形成的角度。本研究的目的是：（i）分析不同象限的CSP和CSJ；（ii）使用Scheimpflug图像测试既定观察分级和测量方法的相关性及可重复性。
使用Pentacam（德国韦茨拉尔奥culus公司）的角膜-巩膜轮廓模块对35名健康眼部参与者（平均年龄25.5±3.1岁；20名女性）的鼻侧、颞侧、上方和下方CSP进行成像。在捕获的Scheimpflug图像上，使用迈尔分级量表（轮廓1为流体凸面；轮廓2为流体切线；轮廓3为明显凸面；轮廓4为明显切线；轮廓5为凹面）对CSP进行主观分级为五种不同的角膜-巩膜过渡。使用ImageJ v1.8.0在相同图像上测量CSJ。在第二次检查时重复分级和测量。通过科恩kappa系数分析CSP分级的观察者内信度。通过配对t检验和方差分析分析重复CSJ测量值与不同象限之间的差异。使用eta系数确定主观CSP分级与CSJ测量之间的关联。
CSP分级系统的观察者内信度较差（kappa = 0.098），而CSJ角的重复测量在各检查之间无统计学显著差异（0.04°；95%CI - 0.21°至0.29°；p = 0.77）。CSJ角范围为172°至180°，鼻侧、颞侧、上方和下方之间无统计学显著差异（p = 0.24）。Eta系数表明CSP分级与CSJ测量之间存在弱关联（η = 0.27；p = 0.04）。
主观CSP分级的可重复性比客观CSJ测量差，客观CSJ测量未检测到子午线之间角度的任何差异。CSP分级与CSJ测量之间的弱关联可能是由于迈尔分级量表的观察者内信度有限所致。此外，CSP分级量表似乎除了考虑CSJ角之外还考虑了其他方面，如巩膜半径。
