Overview
The purpose of this study is the investigation of biomechanical properties of the cornea using computer-aided data analysis. Currently, it is known that keratoconus and glaucoma are ocular disease that are associated with biomechanical alterations of the cornea. Corneal ectasia, especially keratoconus, is a corneal disease that leads to an irreversible loss of visual acuity while the cornea becomes steeper, thinner and irregular. For these patients, surgical intervention (e.g. corneal cross-linking) is performed, in case of disease progression. In glaucoma, the information about corneal alterations serves in two ways, first, correct measurement of intra ocular pressure (IOP); second, early diagnosis of suspects before visual field defects are detectable.
Especially, the Corvis ST is an air-puff tonometer that measures intraocular pressure, corneal thickness (CCT) as well as dynamic corneal response (DCR) parameters. Most of the DCR parameters are affected by IOP and CCT: Therefore, algorithm are needed to determine parameters without impact of IOP and CCT that are describe the biomechanical properties of the cornea.
Description
In this study, an eye twin based on finite element modeling is used to measure advanced properties of corneal biomechanics. Raw data of Corvis ST measurement are exported from the device and imported into the model. The outcome of these calculations are merged together and are compared to further clinical findings (e. g. corneal topography and tomography, axial eye length).
Further information were obtained:
Age, sex, refraction, family history, known duration of disease, previous ocular surgery, systemic diseases, systemic and topical medication; biomicroscopy, anterior optical coherence tomography (OCT), Scheimpflug-based tomography (Pentacam), Biomechanical assessment (Ocular Response Analyzer and Corneal Visualization with the Scheimpflug Technology), optical biometry, confocal microscopy, endothelium cell count.
Eligibility
Inclusion Criteria:
- corneal ectasia (keratoconus) or ectasia suspect
- glaucoma (Primary open angle glaucoma and normal Tension glaucoma) or glaucoma suspect
Exclusion Criteria:
- age under 18 years
- pregnancy