Computer-aided Diagnosis of Ocular Diseases Based on Corneal Biomechanics

Study Overview
=================
Brief Summary
-----------------
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.

Detailed 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.

Official Title
-----------------
Computer-aided Diagnosis of Ocular Diseases Based on Corneal Biomechanics - Selection and Evaluation of Eligible Patients With Certain Ocular Diseases Associated With Biomechanical Alterations

Conditions
-----------------
Corneal Ectasia, Corneal Disease, Corneal Astigmatism, Keratoconus, Glaucoma, Open Angle Glaucoma, Normal Tension Glaucoma

Intervention / Treatment
-----------------
* Diagnostic Test: Corneal biomechanics (Corvis ST, Oculus, Wetzlar, Germany)
* Diagnostic Test: Corneal topography and tomography (Pentacam, Oculus, Wetzlar, Germany)
* Diagnostic Test: Optic nerve head measurement


Participation Criteria
=================
Eligibility Criteria
-----------------
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

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy<br>Healthy eyes without any signs of ocular diseases | Diagnostic Test: Corneal biomechanics (Corvis ST, Oculus, Wetzlar, Germany)<br>* To measure corneal biomechanics with Scheimpflug based tonometry<br>Diagnostic Test: Corneal topography and tomography (Pentacam, Oculus, Wetzlar, Germany)<br>* To measure corneal topography and tomography with Scheimpflug tomograph<br>Diagnostic Test: Optic nerve head measurement<br>* To measure optic nerve excavation<br>|
| Ectasia<br>ectasia suspects early, moderate and advanced keratoconus | Diagnostic Test: Corneal biomechanics (Corvis ST, Oculus, Wetzlar, Germany)<br>* To measure corneal biomechanics with Scheimpflug based tonometry<br>Diagnostic Test: Corneal topography and tomography (Pentacam, Oculus, Wetzlar, Germany)<br>* To measure corneal topography and tomography with Scheimpflug tomograph<br>|
| Glaucoma<br>Normal Tension glaucoma Primary Open-Angle Glaucoma | Diagnostic Test: Corneal biomechanics (Corvis ST, Oculus, Wetzlar, Germany)<br>* To measure corneal biomechanics with Scheimpflug based tonometry<br>Diagnostic Test: Corneal topography and tomography (Pentacam, Oculus, Wetzlar, Germany)<br>* To measure corneal topography and tomography with Scheimpflug tomograph<br>Diagnostic Test: Optic nerve head measurement<br>* To measure optic nerve excavation<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| New biomechanical parameters of the cornea | To detemine biomechanical alterations in different ocular diseases and correlate them with other clinical findings | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dependence of new biomechanical Parameters of the cornea from influencing factors | e. g. corneal thickness, intraocular pressure | 1 year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Cornea, Ectasia, Keratoconus, Finite Element Modelling, computer-aided data analysis, Glaucoma, Corneal biomechanics