Computer-aided Diagnosis of Ocular Diseases Based on Corneal Biomechanics
Condition: Corneal Ectasia; Corneal Disease; Corneal Astigmatism; Keratoconus; Glaucoma; Open Angle Glaucoma; Normal Tension Glaucoma
MeSH terms: Glaucoma; Glaucoma, Open-Angle; Keratoconus; Astigmatism; Low Tension Glaucoma; Corneal Diseases; Dilatation, Pathologic
Study type: Observational

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.
    

Intervention name(s): Corneal biomechanics (Corvis ST, Oculus, Wetzlar, Germany); Corneal topography and tomography (Pentacam, Oculus, Wetzlar, Germany); Optic nerve head measurement
Intervention type(s): Diagnostic Test; Diagnostic Test; Diagnostic Test
Intervention description(s): To measure corneal biomechanics with Scheimpflug based tonometry; To measure corneal topography and tomography with Scheimpflug tomograph; To measure optic nerve excavation
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients with corneal ectasia or glaucoma. Healthy eyes that matching to ocular disease
        groups concerning age.
      
Keywords: Cornea; Ectasia; Keratoconus; Finite Element Modelling; computer-aided data analysis; Glaucoma; Corneal biomechanics