title: Effect of different lubricant eye gels on tear film thickness as measured with ultrahigh-resolution optical coherence tomography.
abstract: OBJECTIVE
  To compare the effect of a single drop of different lubricant eye gels on tear film thickness (TFT) as measured with ultrahigh-resolution optical coherence tomography (UHR-OCT) in patients with mild-to-moderate dry eye disease (DED).
  
  
  METHODS
  The study followed a randomized, single-masked, observer-blinded parallel group design. Patients received a single dose of either unpreserved trehalose 3% + hyaluronic acid 0.15% (TH), hyaluronic acid 0.2% (HA) or polyethylene glycol 0.4% + propylene glycol 0.3% (PP) eye drops. In total, 60 patients were included and TFT was measured using a custom-built UHR-OCT system.
  
  
  RESULTS
  The mean TFT at baseline was 3.5 ± 0.7 μm. There was a significant difference in the time-course of TFT between the three groups (p = 0.001 between groups). Ten minutes after instillation, TFT increased by 155.8 ± 86.6%, 65.7 ± 71.5% and 33.4 ± 19.6% in the PP, TH and HA group, respectively (p < 0.001 between groups). Thirty minutes after instillation, the effect of all three different agents on TFT was comparable. Sixty and 120 min after administration, a significant increase in TFT was only seen for the TH group, but not for the other products (60 min: p < 0.021 between groups; 120 min: p < 0.037 between groups).
  
  
  CONCLUSIONS
  In conclusion, we observed differences in TFT after administration of the lubricant gels. Ten minutes after instillation, a pronounced increase in TFT was observed in all groups. As compared to the other products, the combination of trehalose 3% + hyaluronic acid 0.15% offers a significantly longer increase in TFT indicating for a longer residence time.
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.|Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Piotr A
authors.identifier: http://orcid.org/0000-0002-0944-0438
authors.initials: PA
authors.lastname: Wozniak
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.|Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Doreen
authors.initials: D
authors.lastname: Schmidl
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Bata
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Klemens
authors.initials: K
authors.lastname: Fondi
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Katarzyna J
authors.initials: KJ
authors.lastname: Witkowska
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: Valentin
authors.initials: V
authors.lastname: Aranha Dos Santos
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Carina
authors.initials: C
authors.lastname: Baar
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Kim I
authors.initials: KI
authors.lastname: Room
authors.affiliation: Department of Ophthalmology, Medical University Vienna, Vienna, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Nepp
authors.affiliation: Department of Ophthalmology, Medical University Vienna, Vienna, Austria.
authors.forename: Isabella
authors.initials: I
authors.lastname: Baumgartner
authors.affiliation: Department of Ophthalmology, Emergency University Hospital, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.
authors.forename: Alina
authors.initials: A
authors.lastname: Popa-Cherecheanu
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Garhöfer
authors.affiliation: Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
authors.forename: René M
authors.initials: RM
authors.lastname: Werkmeister
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.|Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.|Singapore Eye Research Institute, Singapore, Singapore.|Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
authors.forename: Leopold
authors.initials: L
authors.lastname: Schmetterer
mesh_terms: D000328:Adult; D000368:Aged; D015352:Dry Eye Syndromes / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D005782:Gels / Q000008:administration & dosage*; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage; D007089:Image Enhancement; D054327:Lubricants / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions; D011092:Polyethylene Glycols / Q000008:administration & dosage; D016037:Single-Blind Method; D013501:Surface-Active Agents / Q000008:administration & dosage; D013666:Tears / Q000737:chemistry* / Q000187:drug effects; D041623:Tomography, Optical Coherence / Q000379:methods*; D055675:Viscosupplements / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D005782:Gels; D054327:Lubricants; D009883:Ophthalmic Solutions; D013501:Surface-Active Agents; D055675:Viscosupplements; D011092:Polyethylene Glycols; D006820:Hyaluronic Acid
keywords: dry eye; eye drops; gels; hyaluronic acid; optical coherence tomography; randomized controlled study; tear film thickness; trehalose