Accuracy of the posterior corneal elevation values of Pentacam HR from different reference surfaces in early ectasia diagnosis

Elkitkat, Rania Serag; Gharieb, Hesham Mohamed; Othman, Ihab Saad

doi:10.1007/s10792-020-01618-8

Cited by 10 publications

(16 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The corneal Q value is a parameter that reflects the corneal shape and represents the degree of corneal asphericity. A more negative Q value of the posterior corneal surface has been reported in early KC ( 15 ). In this study, we found greater astigmatism and a more negative Q value for the posterior corneal surface in the AC group than in the normal group.…”

Section: Discussionmentioning

confidence: 71%

“…A more negative Q value refers to a more prolate shape, with a steeper central cornea and flatter periphery. A previous study reported significant correlations between posterior elevation parameters and posterior Q values as well as posterior aberrations; hence, the authors speculated that the changes in posterior Q values and posterior corneal aberrations were attributed to alterations in corneal posterior elevation ( 15 ). Thus, we hypothesize that the more negative Q value and greater astigmatism of the corneal posterior surface in AC patients might also be induced by alterations in corneal posterior elevation.…”

Section: Discussionmentioning

confidence: 99%

“…For example, Huseynli et al ( 10 ) further showed that among the parameters measured by Pentacam, including corneal topographic parameters, pachymetric parameters, elevation parameters and topometric parameters, anterior and posterior elevation showed the highest AUROCs (0.935 and 0.897, respectively) to differentiate early KC patients from normal subjects. Therefore, among the parameters evaluated in their study, posterior corneal elevation changes were identified as the earliest sign of subclinical KC ( 15 , 16 ). Additionally, in our study, we found that the increased elevations of both the anterior and posterior corneal surfaces were positively correlated with altered TBI, which was identified as a sensitive indicator of KC development risk in AC patients in our previous study ( 19 ).…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies have shown that among the measured topographic parameters, including pachymetric parameters, elevation parameters and topometric parameters, anterior and posterior elevations had the greatest areas under the receiver operating characteristic curve (AUROCs) to discriminate subclinical KC from normal corneas ( 10 , 13 ). KC was thought to start from the posterior surface of the cornea ( 15 , 16 ). Moreover, taking into consideration that compared to the anterior corneal surface, the posterior cornea surface is less affected by corneal epithelial conditions and tear film stability, previous studies proposed posterior corneal elevations as more sensitive and reliable shape parameters for differentiating subclinical KC ( 15 , 16 ).…”

Section: Introductionmentioning

confidence: 99%

“…KC was thought to start from the posterior surface of the cornea ( 15 , 16 ). Moreover, taking into consideration that compared to the anterior corneal surface, the posterior cornea surface is less affected by corneal epithelial conditions and tear film stability, previous studies proposed posterior corneal elevations as more sensitive and reliable shape parameters for differentiating subclinical KC ( 15 , 16 ).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Changes in Anterior and Posterior Corneal Elevation in Patients With Allergic Conjunctivitis

Wang

Feng

et al. 2021

Front. Med.

View full text Add to dashboard Cite

Purpose: To evaluate corneal elevation changes in patients with allergic conjunctivitis (AC) and to analyze their correlations with ocular allergy signs and corneal biomechanical alterations.Methods: Thirty patients (30 eyes) with AC and twenty normal subjects (20 eyes) were included in this prospective study. All participants underwent a complete ocular examination, including corneal tomography by Pentacam and corneal biomechanics evaluation by Corvis ST. AC patients were evaluated for their eye rubbing frequency and ocular allergic signs.Results: The elevation at the thinnest location (TE) and the central location (CE), the elevation difference at the thinnest location (TED) and the central location (CED), and the mean value of elevation difference in the central 4 mm zoom (MED) of both the anterior and posterior corneal surface were significantly higher in the AC group than in the normal group (p < 0.05 for all). In AC patients, only anterior corneal elevation parameters were positively correlated with eye rubbing frequency and ocular allergy sign severity (p < 0.05 for all), while the tomography and biomechanical index (TBI) was positively correlated with the elevation parameters of both the anterior and posterior corneal surfaces (p < 0.05 for all).Conclusion: AC patients carry an increased risk of corneal ectasia. Posterior corneal elevation parameters are sensitive and reliable predictors of keratoconus (KC) risk in AC patients.Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT04299399, identifier [NCT04299399].

show abstract

Section: Discussionmentioning

confidence: 71%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Changes in Anterior and Posterior Corneal Elevation in Patients With Allergic Conjunctivitis

Wang

Feng

et al. 2021

Front. Med.

View full text Add to dashboard Cite

show abstract

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

Flockerzi

Xanthopoulou

Munteanu

et al. 2023

Klin Monbl Augenheilkd

View full text Add to dashboard Cite

ZusammenfassungDie ABCD-Klassifikation des Keratokonus nach Belin ermöglicht eine Stadieneinteilung des Keratokonus basierend auf den Kriterien Vorder- (A) und Rückflächenverkrümmung (B), dünnster Pachymetrie (C) und bestkorrigiertem Visus mit Brille (D). Diese Parameter ermöglichen auch eine Progressionsbeurteilung, berücksichtigen jedoch nicht die korneale Biomechanik. Die korneale Biomechanik ermöglicht mit dem Corvis ST (Oculus, Wetzlar, Deutschland) zunächst die Trennung zwischen gesunden und Keratokonus-Hornhäuten mittels Corvis Biomechanischem Index (CBI) und Tomografisch-Biomechanischem Index (TBI). Bei hoher Reliabilität der Corvis-ST-Messungen in unterschiedlichen Keratokonus-Stadien wurde daher ein biomechanischer Parameter für Keratokonus-Hornhäute entwickelt, der eine biomechanische Stadieneinteilung des Keratokonus ermöglicht und der auf dem linearen Term des CBI basiert. Dieser Corvis Biomechanische Faktor (CBiF) ist zugleich Grundlage der Einführung des biomechanischen E-Stagings, was die ABCD-Klassifikation um den Eckpfeiler der kornealen Biomechanik erweitert. Der Artikel zeigt Stärken und Limitationen der ABCDE-Klassifikation auf. Der (vermeintlich) „einseitige Keratokonus“ erweist sich zumeist als Momentaufnahme einer stark asymmetrisch ausgeprägten Keratektasie. Der reguläre Astigmatismus ist mitunter eine wichtige Differenzialdiagnose zur Keratektasie und schwierig von dieser abzugrenzen. Zudem wird die Anwendung des biomechanischen E-Stagings zur Progressionsbeurteilung des Keratokonus und nach Behandlung mittels kornealem Crosslinking oder Implantation intrakornealer Ringsegmente demonstriert und diskutiert.

show abstract

Corneal Fourier and Belin–Ambrósio Enhanced Ectasia Analysis in Healthy 4-Year-Old White Children

Bajtl¹,

Bjeloš

Bušić

et al. 2023

Cornea

View full text Add to dashboard Cite

Purpose:The aim of this study was to provide normative databases of Fourier analysis (FA) and Belin–Ambrósio enhanced ectasia display (BAD) in healthy White 4-year-old emmetropic children.Methods:FA parameters analyzed were spherical component (SRmin), spherical eccentricity (SEcc), maximal decentration (MD), regular astigmatism at the center (Astigm. C) and periphery (Astigm. P), and irregularity (I). The parameters obtained by BAD included summary indicator BAD D, anterior corneal curvature (K1 and K2, D), maximal keratometry (Kmax, D), maximal Ambrósio relational thinnest (ART max), and pachymetric and BAD indices.Results:Eighty-nine eyes of eighty-nine 4-year-old children were included. The mean values of FA parameters were the following: SRmin 7.77, SEcc 0.600, MD 0.160, Astigm. C 0.070, Astigm. P 0.050, and I 0.019. The mean K1 and K2 in our study group were 42.92 ± 1.29 D and 43.75 ± 1.41 D, with the mean BAD D value 0.42 ± 0.67. The mean PPI min 0.629 ± 0.117, PPI max 1.059 ± 0.155, PPI avg 0.847 ± 0.103, Kmax 44.10 ± 1.39, and median of ART max 515.0 were recorded. No statistically significant differences between male and female sex in any of FA or BAD parameters were found.Conclusions:This is the first study providing large normative data on FA and BAD in 4-year-old White emmetropic children. We proposed a cutoff D value for early ectasia and clinical keratoconus in 4-year-old children.

show abstract

Accuracy of the posterior corneal elevation values of Pentacam HR from different reference surfaces in early ectasia diagnosis

Cited by 10 publications

References 23 publications

Changes in Anterior and Posterior Corneal Elevation in Patients With Allergic Conjunctivitis

Changes in Anterior and Posterior Corneal Elevation in Patients With Allergic Conjunctivitis

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

Corneal Fourier and Belin–Ambrósio Enhanced Ectasia Analysis in Healthy 4-Year-Old White Children

Contact Info

Product

Resources

About