title: Measurement of a multi-layered tear film phantom using optical coherence tomography and statistical decision theory.
abstract: To extend our understanding of tear film dynamics for the management of dry eye disease, we propose a method to optically sense the tear film and estimate simultaneously the thicknesses of the lipid and aqueous layers. The proposed method, SDT-OCT, combines ultra-high axial resolution optical coherence tomography (OCT) and a robust estimator based on statistical decision theory (SDT) to achieve thickness measurements at the nanometer scale. Unlike conventional Fourier-domain OCT where peak detection of layers occurs in Fourier space, in SDT-OCT thickness is estimated using statistical decision theory directly on the raw spectra acquired with the OCT system. In this paper, we demonstrate in simulation that a customized OCT system tailored to ~1 µm axial point spread function (FWHM) in the corneal tissue, combined with the maximum-likelihood estimator, can estimate thicknesses of the nanometer-scale lipid and micron-scale aqueous layers of the tear film, simultaneously, with nanometer precision. This capability was validated in experiments using a physical phantom that consists of two layers of optical coatings that mimic the lipid and aqueous layers of the tear film.
authors.affiliation: Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
authors.forename: Jinxin
authors.initials: J
authors.lastname: Huang
authors.affiliation: The Institute of Optics, University of Rochester, Rochester, New York 14627, USA ; School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Yuan
authors.affiliation: The Institute of Optics, University of Rochester, Rochester, New York 14627, USA ; Department of Optical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
authors.forename: Buyun
authors.initials: B
authors.lastname: Zhang
authors.affiliation: The Institute of Optics, University of Rochester, Rochester, New York 14627, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Xu
authors.affiliation: The Institute of Optics, University of Rochester, Rochester, New York 14627, USA.
authors.forename: Patrice
authors.initials: P
authors.lastname: Tankam
authors.affiliation: Department of Radiology, University of Arizona, Tucson, Arizona 85720, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Clarkson
authors.affiliation: College of Optical Sciences, University of Arizona, Tucson, Arizona 85720, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Kupinski
authors.affiliation: Flaum Eye Institute, University of Rochester, New York 14642, USA.
authors.forename: Holly B
authors.initials: HB
authors.lastname: Hindman
authors.affiliation: Flaum Eye Institute, University of Rochester, New York 14642, USA.
authors.forename: James V
authors.initials: JV
authors.lastname: Aquavella
authors.affiliation: Department of Physics and Optical Science, The University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Suleski
authors.affiliation: The Institute of Optics, University of Rochester, Rochester, New York 14627, USA.
authors.forename: Jannick P
authors.initials: JP
authors.lastname: Rolland
keywords: (030.0030) Coherence and statistical optics; (110.3000) Image quality assessment; (120.0120) Instrumentation, measurement, and metrology; (120.4290) Nondestructive testing; (170.4500) Optical coherence tomography; (330.7327) Visual optics, ophthalmic instrumentation