Please use this identifier to cite or link to this item: doi:10.22028/D291-36855
Title: Combined biomechanical and tomographic keratoconus staging: Adding a biomechanical parameter to the ABCD keratoconus staging system
Author(s): Flockerzi, Elias
Vinciguerra, Riccardo
Belin, Michael Wellington
Vinciguerra, Paolo
Ambrósio, Renato
Seitz, Berthold
Language: English
Title: Acta Ophthalmologica
Volume: 100
Issue: 5
Pages: e1135-e1142
Publisher/Platform: Wiley
Year of Publication: 2022
Free key words: ABCD grading
Corvis Biomechanical Index
DDC notations: 610 Medicine and health
Publikation type: Journal Article
Abstract: Purpose This retrospective cross-sectional study evaluated the potential of an additional biomechanical parameter ‘E’ as an addition to the tomographic ABCD ectasia/keratoconus (KC) staging. Methods The Corvis Biomechanical Factor (CBiF) represents the modified linear term of the Corvis Biomechanical Index (CBI) developed based on 448 KC corneas from the Homburg Keratoconus Center (HKC). The CBiF range was divided into five stages (E0 to E4) to create a grading system according to the ABCD stages. Stage E0 was characterized by values smaller than the 2.5 percentile. The thresholds were created by dividing the CBiF range between the 2.5 and 97.5 percentiles into four groups of equal values (E1–E4). The frequency distribution of ‘E’ was analysed and independently validated based on another 860 KC corneas dataset from Milano and Rio de Janeiro (MR). The relationship between ‘E’ and the ABCD staging was analysed by cross-tabulation. The specificity of ‘E’ was assessed based on healthy controls (112|851) from both datasets (HKC|MR). Results ‘E’ was normally distributed with E0 = 37|30, E1 = 86|200, E2 = 155|354, E3 = 101|206, E4 = 69|70 in the KC group and 96.4%|90.5% of the controls classified E0 in the HKC|MR dataset, respectively. Cross-tabulation revealed that ‘E’ was most comparable to posterior corneal curvature (‘B’) in both datasets, while showing a trend towards more advanced stages in comparison to anterior corneal curvature (‘A’) and thinnest corneal thickness (‘C’). Conclusion The novel Corvis-derived parameter ‘E’ provides a biomechanical staging for ectasia/KC potentially enhancing the ABCD staging and may detect abnormalities before tomographic changes, which requires further studies.
DOI of the first publication: 10.1111/aos.15044
URL of the first publication:
Link to this record: urn:nbn:de:bsz:291--ds-368558
ISSN: 1755-3768
Date of registration: 18-Jul-2022
Faculty: M - Medizinische Fakultät
Department: M - Augenheilkunde
Professorship: M - Prof. Dr. Berthold Seitz
Collections:SciDok - Der Wissenschaftsserver der Universität des Saarlandes

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