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

Abstract

CXL does not deteriorate the repeatability of parameters obtained by using the dynamic Scheimpflug analyzer. Changes in these parameters caused by CXL are true biomechanical alterations.

Repeatability of a Scheimpflug tonometer to measure biomechanical parameters before and after myopic refractive surgery

“…In addition, we have noticed that different from the decrease of corneal biomechanics after myopic refractive surgery, the repeatability of Corvis ST measurement for keratoconic patients with congenital biomechanical damage has been well reported, Herber et al found that advanced-stage keratoconic patients had a significant increase in the CoV compared with keratoconic patients in mild and moderate stages, but still maintained high quality in measuring repeatability. 9 In conclusion, our study demonstrated that the Corvis has excellent repeatability for measuring the basic parameters in all corneas we examined. After LVC surgeries, the DCR parameter measurements showed lower repeatability, and SSI was more variable in all types of post-LVC corneas.…”

“…In addition, we have noticed that different from the decrease of corneal biomechanics after myopic refractive surgery, the repeatability of Corvis ST measurement for keratoconic patients with congenital biomechanical damage has been well reported, Herber et al found that advanced-stage keratoconic patients had a significant increase in the CoV compared with keratoconic patients in mild and moderate stages, but still maintained high quality in measuring repeatability. 9…”

Combined biomechanical and tomographic keratoconus staging: Adding a biomechanical parameter to the ABCD keratoconus staging system

“…A predisposition for the application and interpretation of these results is a high reliability of the CST measurements, which has been proven in recent studies: The CST measurements have been shown to be of excellent reliability in mild to moderate KC (Yang et al 2019), in three different KC severity stages (Herber et al 2020) and in one study assessing every KC stage according to the topographical KC classification (TKC, Flockerzi et al 2021b). Based on this high reliability of the CST measurements in all KC stages and the fact that the biomechanical staging was developed without using biomechanical information for initial diagnosis of KC, it can be assumed that the new biomechanical parameter 'E' introduced in this study is a robust parameter for a biomechanical KC grading.…”

“…2019), in three different KC severity stages (Herber et al. 2020) and in one study assessing every KC stage according to the topographical KC classification (TKC, Flockerzi et al. 2021b).…”

Das biomechanische E-Staging: In-vivo-Biomechanik beim Keratokonus

“…Diese Ergebnisse erlauben die Schlussfolgerung, dass sich die menschliche Hornhaut nach erfolgtem Crosslinking wieder ihrem präoperativen biomechanischen Status nach etwa 1 – 2 Jahren annähert. Die alleinige Zunahme der Hornhautsteifigkeit postoperativ kann dennoch weitaus früher beobachtet werden: Eine weitere Studie untersuchte die Entwicklung biomechanischer Corvis-ST-Einzelparameter 1, 6 und 12 Monate nach erfolgtem Crosslinking (9 mW/cm 2 , 10 min) und kam zu dem Schluss, dass einzelne Parameter (wie der integrierte Radius und der Stress-Strain-Index) trotz niedriger gemessener Hornhautdicke insbesondere 1 Monat postoperativ eine Zunahme der Hornhautsteifigkeit anzeigen und dass sich dieser Effekt bereits nach 12 Monaten wieder reduziert 41 , 42 .…”