APPARATUS AND METHOD FOR IN-VIVO MEASUREMENT OF CORNEAL BIOMECHANICAL RESPONSE

摘要

Apparatus and methods are presented for non-contact in-vivo measurement of one or more properties of a cornea or tear film with spatial resolution. In certain embodiments the cornea/tear film is probed at substantially normal incidence with a converging array of beamlets from a multi-wavelength optical source, and the reflected light analysed interferometrically to generate a time sequence of pachymetry maps. Thickness variations arising from differences between the external and intraocular pressure, e.g. from the ocular pulse or externally applied pressure changes, are measured and analysed to obtain information on a biomechanical response of the cornea. In preferred embodiments the time variation in tear film thickness is measured and subtracted to yield normalised pachymetry data for the biomechanical analysis. In certain embodiments the apparatus is configured to measure the dynamics and profile of the tear film, using either converging or substantially parallel arrays of beamlets.