Repeatability of Corneal Deformation Response Parameters by Dynamic Ultra High-speed Scheimpflug Imaging in Normal and Keratoconus Eyes

Abstract

To assess the repeatability of corneal dynamic response (CDR) parameters in normal and keratoconus (KC) eyes using ultra high-speed Scheimpflug imaging. Methods: Prospective, comparative, observational study, including eyes of 112 patients that underwent high-speed Scheimpflug imaging analysis (Corvis ST, OCULUS). Twenty-one CDR parameters were evaluated to asses repeatability using: coefficient of repeatability (CR), coefficient of variation, intraclass correlation coefficient (ICC) and within-subject SD. Three consecutive measurements by the same operator were performed for each eye. Results: There were no significant differences between the three consecutive measurements for all parameters in both normal and KC eyes. 71.42% (15 of the 21 parameters evaluated) and 85.71% (18 of the 21 parameters) were highly repeatable in the normal and KC group, respectively. The tomographic biomechanical index (TBI), corneal biomechanical index (CBI), and stiffness parameter (SPA1) showed an ICC of 0.978, 0.954, and 0.958 in normal and 0.982, 0.892, and 0.978 in KC eyes, respectively. The CR in normal eyes for TBI, CBI, and SPA1 were 0.169, 0.242, and 14.12, respectively, and for KC eyes 0.06, 0.23, and 13.64, respectively. Conclusions: Most of the corneal dynamic response parameters were highly repeatable in normal and KC eyes.

Repeatability of corneal deformation response parameters by dynamic ultra–high-speed Scheimpflug imaging before and after corneal crosslinking

“…19,27 Thus, it has been reported that the reliability is comparable in healthy eyes or in eyes with mild or moderate KC, which was shown in 2 different comparison studies. 28,29 In addition, this study investigated 2 new parameters, the SSI and the CBiF, whose repeatability was investigated in KC for the first time. The CR, CoV, and ICC for the SSI were between 0.17 and 0.22, 6.16% and 6.67%, and 0.886 and 0.913 (for both groups), respectively.…”

In Vivo Corneal Biomechanical Properties in a Selected Chinese Population, Measured Using the Corneal Visualization Scheimpflug Technology

“…The investigation of corneal biomechanics recently gained space as a hot topic in ophthalmology mainly due to its wide applications ( Roberts etal., 2014 ). Corneal biomechanical properties were known to assist with detecting corneal diseases ( Vinciguerra et al, 2017a ; Reinprayoon et al, 2021 ; Ziaei et al, 2021 ; Henriquez et al, 2022 ), predicting refractive outcomes before corneal refractive surgery ( Chen et al, 2018 ), judging different protocols of collagen crosslinking treatments ( Greenstein et al, 2012 ), and even selecting intracorneal ring implants ( Bao et al, 2016 ; Shen et al, 2022 ).…”

A Corneal Biomechanical Study Measured with a Scheimpflug Dynamic Analyser in Soft Contact Lens Wearers

“…The Corvis ST ® measured more dynamic corneal biomechanical parameters with high repeatability [39]. The results of the study of Lin et al showed that several baseline CST parameters associated with AXL elongation and the related parameters differed after DISC and OK lens treatments [37].…”