title: Terahertz sensing of corneal hydration.
abstract: An indicator of ocular health is the hydrodyanmics of the cornea. Many corneal disorders deteriorate sight as they upset the normal hydrodynamics of the cornea. The mechanisms include the loss of endothelial pump function of corneal dystophies, swelling and immune response of corneal graft rejection, and inflammation and edema, which accompany trauma, burn, and irritation events. Due to high sensitivity to changes of water content in materials, a reflective terahertz (300 GHz and 3 THz) imaging system could be an ideal tool to measure the hydration level of the cornea. This paper presents the application of THz technology to visualize the hydration content across ex vivo porcine corneas. The corneas, with a thickness variation from 470 - 940 µm, were successfully imaged using a reflective pulsed THz imaging system, with a maximum SNR of 50 dB. To our knowledge, no prior studies have reported on the use of THz in measuring hydration in corneal tissues or other ocular tissues. These preliminary findings indicate that THz can be used to accurately sense hydration levels in the cornea using a pulsed, reflective THz imaging system.
authors.affiliation: UCLA Department of Surgery, UCSB Department of Electrical and Computer Engineering, Los Angeles, CA 90095, USA. rst@ece.ucsb.edu
authors.forename: Rahul S
authors.initials: RS
authors.lastname: Singh
authors.forename: Priyamvada
authors.initials: P
authors.lastname: Tewari
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Bourges
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Hubschman
authors.forename: David B
authors.initials: DB
authors.lastname: Bennett
authors.forename: Zachary D
authors.initials: ZD
authors.lastname: Taylor
authors.forename: H
authors.initials: H
authors.lastname: Lee
authors.forename: Elliott R
authors.initials: ER
authors.lastname: Brown
authors.forename: Warren S
authors.initials: WS
authors.lastname: Grundfest
authors.forename: Martin O
authors.initials: MO
authors.lastname: Culjat
mesh_terms: D000818:Animals; D001834:Body Water / Q000502:physiology*; D003315:Cornea / Q000473:pathology; D003316:Corneal Diseases / Q000175:diagnosis* / Q000473:pathology; D003952:Diagnostic Imaging / Q000379:methods; D004867:Equipment Design; D005123:Eye / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D007249:Inflammation; D011126:Polypropylenes / Q000737:chemistry; D015203:Reproducibility of Results; D013552:Swine; D055068:Terahertz Spectroscopy / Q000379:methods*; D014785:Vision, Ocular
chemical_list: D011126:Polypropylenes