TY - JOUR
T1 - Dynamic ultra high speed scheimpflug imaging for assessing corneal biomechanical properties
AU - Ambrósio, Renato
AU - Ramos, Isaac
AU - Luz, Allan
AU - Faria, Fernando Correa
AU - Steinmueller, Andreas
AU - Krug, Matthias
AU - Belin, Michael W.
AU - Roberts, Cynthia Jane
PY - 2013
Y1 - 2013
N2 - 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.
AB - 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.
KW - Biomechanics
KW - Cornea/physiology
KW - Corneal topography/methods
KW - Ocular/methods
KW - Tonometry
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U2 - 10.1590/S0034-72802013000200005
DO - 10.1590/S0034-72802013000200005
M3 - Article
AN - SCOPUS:84880594873
SN - 0034-7280
VL - 72
SP - 99
EP - 102
JO - Revista Brasileira de Oftalmologia
JF - Revista Brasileira de Oftalmologia
IS - 2
ER -