Patent ID: 9615735
Date: 2017-04-11
CPC Classifications: A61B

Claim:
1. A method of determining thickness of lipid and aqueous layers of a tear film, the method comprising: directing light from a light source to an eye, the eye having a tear film including a lipid layer and an aqueous layer; collecting light at a light detector, the collected light including back-reflected light from the eye; generating a spectrum array based on the light collected at the light detector; inputting the spectrum array into a statistical estimator comprising a processor and a memory; at the statistical estimator, determining an estimate of a lipid layer thickness and an estimate of an aqueous layer thickness for the lipid and aqueous layers based on a statistical likelihood of the inputted spectrum array being generated by the estimated lipid layer thickness and the estimated aqueous layer thickness out of different possible combinations of potential lipid layer thicknesses and potential aqueous layer thicknesses; wherein collecting light at the light detector comprises collecting light at a spectrometer; wherein the light source and the spectrometer are components of an optical coherence tomography system, the optical coherence tomography system comprising an axial point spread function of 2 μm or less for a corneal epithelium.