Effect of Four Different Diagnostic Eye Drops on Tear Film Thickness

Effect of Single Instillation of Four Different Diagnostic Eye Drops on Tear Film Thickness in Healthy Subjects

The use of topical anesthesia as well as corneal vital staining with fluorescein is an inevitable part of various ophthalmological examinations and surgical treatments. However, eye drops that don't come in single dose packages are required to contain preservatives such as chlorhexidine diacetate. An increasing number of surveys proves the partly severe side effects that preservative-containing eye drops may induce. The aim of the present study therefore is to investigate the effects of four different topical diagnostic eye drops (Novain®, Minims Oxybuprocaine Hydrochloride®, Thilorbin® and Minims®) on tear film thickness in healthy subjects. Tear film thickness will be measured at baseline and at defined time points after single instillation. The course of tear film thickness during the study day will provide information about the influence on tear film stability of the four different eye drops. Healthy subjects will receive Novain®, Minims Oxybuprocaine Hydrochloride®, Thilorbin® and Minims® eye drops on 4 different study days in a randomized order. Assessment of lipid layer thickness will be performed before and at pre-specified time points after instillation as secondary outcome. Other clinical measures such as determination of tear film break up time (TFBUT), corneal sensation, and Schirmer I test will be performed. The study will be conducted in a randomized, single masked, observer blinded four-way cross-over design. Subjects will receive all four diagnostic eye drops on 4 different study days in a randomized order.

Study Overview

• Status: Completed
• Conditions: Ocular Surface Disease; Tear Film Characteristics
• Intervention / Treatment: Drug: Oxybuprocaine MDU; Drug: Oxybuprocaine SDU; Drug: Fluorescein SDU; Drug: Oxybuprocaine/fluorescein SDU

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 3

Contacts and Locations

Study Locations

• Austria
  • Vienna, Austria, 1090
    • Department of Clinical Pharmacology, Medical University of Vienna

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Men and women aged at least 18 years
• Written informed consent prior to study-related procedures
• Normal ophthalmic findings
• No use of eye drops including topical lubricants in the 4 weeks before screening

Exclusion Criteria:

• Participation in a clinical trial in the 3 weeks preceding the study
• Symptoms of a clinically relevant illness in the 3 weeks before the first study day
• Presence or history of a severe medical condition as judged by the clinical investigator
• Intake of parasympathomimetic or anti-psychotic drugs
• Wearing of contact lenses
• Dry eye syndrome (Schirmer I test ≤10mm or TFBUT <10 sec.)
• Glaucoma in the medical history
• Treatment with corticosteroids in the 4 weeks preceding the study
• Topical treatment with any ophthalmic drug in the 4 weeks preceding the study
• Ocular infection or clinically significant inflammation
• Ocular surgery in the 3 months preceding the study
• Sjögren's syndrome
• Stevens-Johnson syndrome
• History of allergic conjunctivitis
• Pregnancy, planned pregnancy or lactating
• Known hypersensitivity to any component of the study medication

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Oxybuprocaine MDU; Subjects will receive 30µl of oxybuprocaine preserved in multi-dose units (MDU) in both eyes after the baseline measurements on the randomized study day	Drug: Oxybuprocaine MDU; the effect of instillation of 30µl of oxybuprocaine preserved as multi-dose unit (MDU) in both eyes will be investigated
Active Comparator: Oxybuprocaine SDU; Subjects will receive 30µl of oxybuprocaine preserved in single-dose units (SDU) in both eyes after the baseline measurements on the randomized study day	Drug: Oxybuprocaine SDU; the effect of instillation of 30µl of oxybuprocaine preserved as single-dose unit (SDU) in both eyes will be investigated
Active Comparator: Fluorescein SDU; Subjects will receive 30µl of fluorescein preserved in single-dose units (SDU) in both eyes after the baseline measurements on the randomized study day	Drug: Fluorescein SDU; the effect of instillation of 30µl of fluorescein preserved as single-dose unit (SDU) in both eyes will be investigated
Active Comparator: Oxybuprocaine/fluorescein SDU; Subjects will receive 30µl of oxybuprocaine/fluorescein preserved in single-dose units (SDU) in both eyes after the baseline measurements on the randomized study day	Drug: Oxybuprocaine/fluorescein SDU; the effect of instillation of 30µl of oxybuprocaine/fluorescein preserved as single-dose unit (SDU) in both eyes will be investigated

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of tear film thickness	Change of tear film thickness as measured with optical coherence tomography predose and at defined time points (10±5, 20±5, 40±5, 60±5, 120±10 and 240±10 minutes) after single instillation	Predose and at defined time points (10±5, 20±5, 40±5, 60±5, 120±10 and 240±10 minutes) after single instillation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Corneal Sensation	The measurement of corneal sensation predose and at defined time points (10±5, 20±5, 40±5, 60±5, 120±10 and 240±10 minutes) after single instillation using a Cochet-Bonnet aesthesiometer	Predose and at defined time points (10±5, 20±5, 40±5, 60±5, 120±10 and 240±10 minutes) after single instillation
Tear film break up time	Change of tear film break up time from baseline to 240±10 minutes after single instillation	Change of tear film break up time predose 240±10 minutes after single instillation
Schirmer 1 test	Change of Schirmer 1 test as measured from baseline to 240±10 minutes after single instillation	Baseline to 240±10 minutes after single instillation

Collaborators and Investigators

• Sponsor: Medical University of Vienna

Study record dates

Study Major Dates

• Study Start (Actual): June 10, 2020
• Primary Completion (Actual): October 28, 2020
• Study Completion (Actual): October 28, 2020

Study Registration Dates

• First Submitted: November 13, 2025
• First Submitted That Met QC Criteria: November 13, 2025
• First Posted (Actual): November 17, 2025

Study Record Updates

• Last Update Posted (Actual): November 17, 2025
• Last Update Submitted That Met QC Criteria: November 13, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: benoxinate
• Other Study ID Numbers: OPHT-250618

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No