Repeatability, Reproducibility, and Age Dependency of Dynamic Scheimpflug-Based Pneumotonometer and Its Correlation With a Dynamic Bidirectional Pneumotonometry Device

Bak‐Nielsen, Sashia; Pedersen, Iben Bach; Ivarsen, Anders; Hjortdal, Jesper

doi:10.1097/ico.0000000000000293

Cited by 57 publications

(53 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It presented good repeatability, CV of 3.8%, and reproducibility, CV of 5.7%. It is consistent with other studies where the CV for repeatability ranged from 3.64% to 4.3% [18–20]. …”

Section: Discussionsupporting

confidence: 93%

See 1 more Smart Citation

Repeatability and Reproducibility of Intraocular Pressure and Dynamic Corneal Response Parameters Assessed by the Corvis ST

Lopes

Roberts

Elsheikh

et al. 2017

Journal of Ophthalmology

View full text Add to dashboard Cite

Purpose To assess the repeatability and reproducibility of dynamic corneal response parameters measured by the Corvis ST (Oculus, Wetzlar, Germany). Methods One eye randomly selected from 32 healthy volunteers was examined by the Corvis ST. Three different devices were used in an alternated random order for taking three measurements at each device in each subject. Standard intraocular pressure (IOP), the biomechanical-compensated IOP (bIOP), and DCR parameters were evaluated. The within-subject standard deviation (ζw) and coefficient of variation (CV) were assessed. Results Regarding pressure indices, the ζw was below 1 mmHg for repeatability (0.98 for IOP and 0.89 for bIOP) and the CV was 6.6% for IOP and 6.1% for bIOP. For reproducibility, the ζw was around 1 mmHg (1.12 for IOP and 1.05 for bIOP) and the CV was 7.6% for IOP and 7.1% for bIOP. Most of DCR indices presented CV for repeatability below 4%. For reproducibility, the CV of most of the indices were below 6%. The deformation amplitude (DA) ratio in 1 mm and integrated radius were below 4% (1.2% and 3.8%, resp.). Conclusions The Corvis ST showed good precision (repeatability and reproducibility) for IOP measurements and for DCR in healthy eyes.

show abstract

“…It presented good repeatability, CV of 3.8%, and reproducibility, CV of 5.7%. It is consistent with other studies where the CV for repeatability ranged from 3.64% to 4.3% [18–20]. …”

Section: Discussionsupporting

confidence: 93%

“…Ali et al found similar results to IOP repeatability with CV of 6.1% [19]. Bak-Nielsen et al assessed not just repeatability but also reproducibility with measurements in different days [20]. In their study, they found slightly lower values of CV, 4.2% for repeatability and 6.5% for reproducibility.…”

Section: Discussionmentioning

confidence: 81%

Repeatability and Reproducibility of Intraocular Pressure and Dynamic Corneal Response Parameters Assessed by the Corvis ST

Lopes

Roberts

Elsheikh

et al. 2017

Journal of Ophthalmology

View full text Add to dashboard Cite

show abstract

“…Significant positive associations among age and HCDA, HCDLA, HCDLAr, 28 and HCT 27 reported in previous studies did not agree with the results of the current study. The significant association between age and A2T reported in another previous study 35 was confirmed by the current study, but the current study did not confirm the associations of age with other parameters (A1T, A2V, radius, and HCDA) reported in the same paper.…”

Section: Agecontrasting

confidence: 54%

Factors Associated With Corneal Deformation Responses Measured With a Dynamic Scheimpflug Analyzer

Miki

Maeda

Ikuno

et al. 2017

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

PURPOSE. The purpose of this study was to clarify correlations between corneal deformation parameters measured with a dynamic Scheimpflug analyzer and baseline factors such as axial length, intraocular pressure (IOP), age, central corneal thickness (CCT), and corneal curvature.METHODS. Ninety-six eyes of 96 healthy subjects (mean 55.2 6 16.1 years of age) were examined using a dynamic Scheimpflug analyzer. Eighteen of 35 deformation parameters were selected for analyses based on measurement reliability and clinical relevance. The associations between corneal deformation parameters and axial length, IOP, age, CCT, and average corneal power were evaluated using multivariate regression analyses.RESULTS. Deformation parameters were correlated significantly with axial length (n ¼ 13), IOP (n ¼ 13), age (n ¼ 8), and CCT (n ¼ 6) in the multivariate models. Longer axial length corresponded with greater corneal deformability, less viscous damping, and less movement of the entire eye. Higher IOP was associated with greater corneal resistance and less movement of the entire eye. Older age was associated with less corneal deformability and greater movement of the entire eye. Corneal curvature was correlated significantly with only three deformation parameters.CONCLUSIONS. This study clarified the substantial impact of axial length, age, and IOP on the biomechanical responses of the cornea and the entire eye. In contrast, corneal curvature did not affect most of the deformation parameters. The current results confirmed the importance of corneal biomechanics, especially in eyes with longer axial length and in older subjects.

show abstract

“…Thus, we postulate that the asymmetry of A2L and A1DA may be affected by asymmetry arrangement of corneal collagen. Besides the poor repeatability and reproducibility of A2L and A1DA which were reported by previous studies [25–27] also could explain some of differences found between the right eye and the left eye. However, further studies are warrant to clarify the exactly mechanism.…”

Section: Discussionmentioning

confidence: 85%

Corneal biomechanical properties in healthy children measured by corneal visualization scheimpflug technology

Ding

et al. 2017

BMC Ophthalmol

View full text Add to dashboard Cite

BackgroundThe aim of this study was to evaluate corneal biomechanical properties in a population of healthy children in China using corneal visualization Scheimpflug technology (CST).MethodsAll children underwent complete bi-ocular examinations. CST provided intraocular pressure (IOP) and corneal biomechanical parameters, including time, velocity, length and deformation amplitude at first applanation (A1T, A1V, A1L, A1DA), at second applanation (A2T, A2V, A2L, A2DA), highest concavity time (HCT), maximum deformation amplitude (MDA), peak distance (PD), and radius of curvature (RoC). Pearson correlation analysis was used to assess the impacts of demographic factors, central corneal thickness (CCT), spherical equivalent (SE), and IOP on corneal biomechanics.ResultsOne hundred eight subjects (32 girls and 76 boys) with the mean age of 10.80 ± 4.13 years (range 4 to18 years) were included in the final analyses. The right and left eyes were highly symmetrical in SE (p = 0.082), IOP (p = 0.235), or CCT (p = 0.210). Mean A1T of the right eyes was 7.424 ± 0.340 ms; the left eyes 7.451 ± 0.365 ms. MDA was 0.993 ± 0.102 mm in the right eyes and 0.982 ± 0.100 mm in the left eyes. Mean HCT of the right eyes was 16.675 ± 0.502 ms; the left eyes 16.735 ± 0.555 ms. All CST parameters of both eye were remarkably symmetrical with the exception of A2L (p = 0.006), A1DA (p = 0.025). The majority of CST parameters of both eyes were significantly correlated with CCT and IOP (p < 0.05). However, age, SE, and sex exert little influence on the CST measurements.ConclusionsThis study found interocular symmetry in corneal biomechanics in healthy children eyes. Several CST biomechanical parameters in children are modified by CCT and IOP.

show abstract

Repeatability, Reproducibility, and Age Dependency of Dynamic Scheimpflug-Based Pneumotonometer and Its Correlation With a Dynamic Bidirectional Pneumotonometry Device

Abstract: The considerable variation in repeatability and reproducibility should be taken into account when using the Corvis. Corvis parameters showed poor correlation with CH and CRF obtained by ORA measurements.

Cited by 57 publications

References 30 publications

Repeatability and Reproducibility of Intraocular Pressure and Dynamic Corneal Response Parameters Assessed by the Corvis ST

Repeatability and Reproducibility of Intraocular Pressure and Dynamic Corneal Response Parameters Assessed by the Corvis ST

Factors Associated With Corneal Deformation Responses Measured With a Dynamic Scheimpflug Analyzer

Corneal biomechanical properties in healthy children measured by corneal visualization scheimpflug technology

Contact Info

Product

Resources

About