Purpose: To evaluate the correlation of corneal biomechanical parameters with structural characteristics in normal, keratoconic, and collagen crosslinked eyes.
Methods: A prospective observational study that included 50 normal, 100 keratoconic, and 25 crosslinked eyes. All eyes were imaged using a Scheimpflug camera and an ocular response analyzer. The main outcome measures analyzed were central corneal thickness (CCT), corneal volume (CV), maximal keratometry (Kmax), corneal hysteresis (CH), and corneal resistance factor (CRF).
Results: Significant differences were noted among all 3 groups of eyes for CCT, CV, Kmax, CH, and CRF values (P < 0.05 by analysis of variance). CH and CRF correlated negatively (CH, r = -0.40; CRF, r = -0.44; both P < 0.0001) with the Pentacam topographic keratoconus classification. Both CH and CRF correlated positively with CCT and CV for the normal, keratoconic, and crosslinked eyes. In contrast, significant negative correlations were observed between CH, CRF, and Kmax in the keratoconic eyes (CH, r = -0.43; CRF, r = -0.53; both P < 0.0001), whereas no association was noted for the normal and crosslinked eyes.
Conclusions: CH and CRF are influenced by the corneal structure, with higher values noted in corneas with greater thickness and volume. Corneal biomechanical parameters progressively decrease as the severity of keratoconus increases. After collagen crosslinking, the relationship of the corneal curvature to the biomechanical profile is similar to normal eyes.
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http://dx.doi.org/10.1097/ICO.0000000000000434 | DOI Listing |
Ophthalmic Physiol Opt
December 2024
Department of Ophthalmology, University Hospital Carl Gustav Carus, TU Dresden, Dresden, Germany.
Purpose: To compare the parameters and indices of a novel swept-source optical coherence tomography device (SS-OCT, ANTERION) with those of a rotating Scheimpflug camera (RSC)-based tomograph (Pentacam) in normal and keratoconic (KC) eyes.
Methods: This prospective, monocentric, cross-sectional study included individuals with unoperated normal and KC eyes, selecting one eye per subject. Ectasia-specific parameters analysed with the SS-OCT were difference in mean keratometry (K) in the inferior and superior meridians, maximum keratometry value (K), elevation of the posterior surface at the thinnest point, screening corneal objective risk of ectasia (SCORE) and thinnest point thickness.
J Curr Ophthalmol
October 2024
Department of Ophthalmology, Rayong Hospital, Rayong, Thailand.
Exp Eye Res
November 2024
Centre for Ocular Regeneration (CORE), Prof. Brien Holden Eye Research Centre (BHERC), L V Prasad Eye Institute, Hyderabad, India. Electronic address:
Keratoconus, a progressive corneal disorder characterized by the thinning and conical protrusion of the cornea because of collagen degradation, poses significant challenges to both clinicians and researchers. Most successful animal models of keratoconus are based on genetic mutations and knock-outs in mice and rats that hinder normal corneal stromal architecture, thickness, or strength. While mice and rat models are suitable to study the molecular mechanism and physiological changes to the cornea, they are not suitable for experimental research; especially for surgical interventions like: deep anterior lamellar keratoplasty (DALK), stromal lenticule addition keratoplasty, and other advanced therapies.
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October 2024
International Vision Correction Research Centre (IVCRC), Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.
Purpose: To develop and test a parameter for early keratoconus screening by quantifying the localized epithelial thickness differences in keratoconic eyes.
Methods: The cross-sectional study included 189 eyes of 116 subjects in total: 86 eyes of 54 keratoconus patients with bilateral ectasia and 40 eyes of 20 healthy subjects in the parameter-development dataset and 42 eyes of 21 keratoconus patients with asymmetric ectasia and 21 eyes of 21 healthy subjects in the parameter-validation dataset. Epithelial thickness maps were obtained using anterior segment optical coherence tomography and the inter-zonal epithelial thickness differences were calculated.
J Ophthalmol
June 2024
Zentrum für Refraktive Chirurgie, Augenzentrum am St. Franziskus Hospital, Münster, Germany.
Purpose: Assessing the applicability of an algorithm developed for keratoconus detection in adolescents. This algorithm relies on optical coherence tomography (OCT) and incorporates features related to corneal pachymetric and epithelial thickness alterations.
Methods: We retrospectively reviewed charts of patients under the age of 18 and divided them into four groups according to the Belin-Ambrosio display (Pentacam): normal, manifest, and subclinical keratoconus, as well as very asymmetric eye with normal topography and tomography (VAE-NTT).
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