Dynamic ultra high speed scheimpflug imaging for assessing corneal biomechanical properties

Renato Ambrósio, Isaac Ramos, Allan Luz, Fernando Correa Faria, Andreas Steinmueller, Matthias Krug, Michael W. Belin, Cynthia Jane Roberts

Research output: Contribution to journalArticle

84 Scopus citations

Abstract

Objective: To describe a novel technique for clinical characterization of corneal biomechanics using non-invasive dynamic imaging. Methods: Corneal deformation response during non contact tonometry (NCT) is monitored by ultra-high-speed (UHS) photography. The Oculus Corvis ST (Scheimpflug Technology; Wetzlar, Germany) has a UHS Scheimpflug camera, taking over 4,300 frames per second and of a single 8mm horizontal slit, for monitoring corneal deformation response to NCT. The metered collimated air pulse or puff has a symmetrical configuration and fixed maximal internal pump pressure of 25 kPa. The bidirectional movement of the cornea in response to the air puff is monitored. Results: Measurement time is 30ms, with 140 frames acquired. Advanced algorithms for edge detection of the front and back corneal contours are applied for every frame. IOP is calculated based on the first applanation moment. Deformation amplitude (DA) is determined as the highest displacement of the apex in the highest concavity (HC) moment. Applanation length (AL) and corneal velocity (CVel) are recorded during ingoing and outgoing phases. Conclusion: Corneal deformation can be monitored during non contact tonometry. The parameters generated provide clinical in vivo characterization of corneal biomechanical properties in two dimensions, which is relevant for different applications in Ophthalmology.

Original languageEnglish (US)
Pages (from-to)99-102
Number of pages4
JournalRevista Brasileira de Oftalmologia
Volume72
Issue number2
DOIs
StatePublished - Jul 30 2013

Keywords

  • Biomechanics
  • Cornea/physiology
  • Corneal topography/methods
  • Ocular/methods
  • Tonometry

ASJC Scopus subject areas

  • Surgery
  • Ophthalmology

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