Tear film measurement by optical reflectometry technique

Hui Lu, Michael Renxun Wang, Jianhua Wang, Meixiao Shen

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 μm. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 μm with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58% of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle.

Original languageEnglish
Article number027001
JournalJournal of Biomedical Optics
Volume19
Issue number2
DOIs
StatePublished - Feb 1 2014

Fingerprint

reflectometers
Reflectometers
Film thickness
film thickness
contact lenses
Galvanometers
Contact lenses
galvanometers
spectral reflectance
scanners
alignment
reflectance
Wavelength
wavelengths
Lipids
lipids
Optical fibers
Lenses
Refractive index
acquisition

Keywords

  • Interferometry
  • Ophthalmology
  • Optical devices
  • Reflectometry

ASJC Scopus subject areas

  • Biomedical Engineering
  • Biomaterials
  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics

Cite this

Tear film measurement by optical reflectometry technique. / Lu, Hui; Wang, Michael Renxun; Wang, Jianhua; Shen, Meixiao.

In: Journal of Biomedical Optics, Vol. 19, No. 2, 027001, 01.02.2014.

Research output: Contribution to journalArticle

@article{c748daa17fa148cbb48c0fc3c1a61fed,
title = "Tear film measurement by optical reflectometry technique",
abstract = "Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 μm. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 μm with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58{\%} of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle.",
keywords = "Interferometry, Ophthalmology, Optical devices, Reflectometry",
author = "Hui Lu and Wang, {Michael Renxun} and Jianhua Wang and Meixiao Shen",
year = "2014",
month = "2",
day = "1",
doi = "10.1117/1.JBO.19.2.027001",
language = "English",
volume = "19",
journal = "Journal of Biomedical Optics",
issn = "1083-3668",
publisher = "SPIE",
number = "2",

}

TY - JOUR

T1 - Tear film measurement by optical reflectometry technique

AU - Lu, Hui

AU - Wang, Michael Renxun

AU - Wang, Jianhua

AU - Shen, Meixiao

PY - 2014/2/1

Y1 - 2014/2/1

N2 - Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 μm. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 μm with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58% of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle.

AB - Evaluation of tear film is performed by an optical reflectometer system with alignment guided by a galvanometer scanner. The reflectometer system utilizes optical fibers to deliver illumination light to the tear film and collect the film reflectance as a function of wavelength. Film thickness is determined by best fitting the reflectance-wavelength curve. The spectral reflectance acquisition time is 15 ms, fast enough for detecting film thickness changes. Fast beam alignment of 1 s is achieved by the galvanometer scanner. The reflectometer was first used to evaluate artificial tear film on a model eye with and without a contact lens. The film thickness and thinning rate have been successfully quantified with the minimum measured thickness of about 0.3 μm. Tear films in human eyes, with and without a contact lens, have also been evaluated. A high-contrast spectral reflectance signal from the precontact lens tear film is clearly observed, and the thinning dynamics have been easily recorded from 3.69 to 1.31 μm with lipid layer thickness variation in the range of 41 to 67 nm. The accuracy of the measurement is better than ±0.58% of the film thickness at an estimated tear film refractive index error of ±0.001. The fiber-based reflectometer system is compact and easy to handle.

KW - Interferometry

KW - Ophthalmology

KW - Optical devices

KW - Reflectometry

UR - http://www.scopus.com/inward/record.url?scp=84897788943&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84897788943&partnerID=8YFLogxK

U2 - 10.1117/1.JBO.19.2.027001

DO - 10.1117/1.JBO.19.2.027001

M3 - Article

C2 - 24500519

AN - SCOPUS:84897788943

VL - 19

JO - Journal of Biomedical Optics

JF - Journal of Biomedical Optics

SN - 1083-3668

IS - 2

M1 - 027001

ER -