Evaluation of a Novel Method for Increasing Intraocular Pressure in Healthy Subjects

Adequate perfusion is necessary for maintaining tissue function. This applies also for the eye, in which ocular perfusion pressure (OPP) is generally estimated as the difference between mean arterial pressure (MAP) and intraocular pressure (IOP). In the latter formula, IOP substitutes for central retinal venous pressure (CRVP), which is assumed to be slightly higher than IOP to allow blood flow to exit the eye. It has, however, been found that in some patients CRVP is elevated and significantly higher than IOP, which would lead to a decrease in OPP which is not taken in account with the proposed formula. Therefore, techniques for measurement of CRVP are warranted. Recently, a new, method for measurement of this parameter without corneal contact has been introduced. Briefly, with this method, IOP is elevated until the vein collapses, which then equals CRVP. In the present study this technique will be applied in 12 healthy subjects to validate whether the values that are preset by the device correlate to measurements obtained with standard Goldmann applanation tonometry. For this purpose, IOP will be experimentally increased in steps of approximately 5mmHg until it reaches 40mmHg as measured by applanation tonometry. After a resting period of 30 minutes, IOP will be again increased stepwise to 40 mmHg while retinal vessel diameters will be monitored using dynamic vessel analyzer. During this session CRVP will be measured. After another resting period of 30 minutes IOP will be stepwise increased a third time and after each step OCT, OCT-A and OCT EDI will be performed.

Study Overview

• Status: Completed
• Conditions: Intraocular Pressure
• Intervention / Treatment: Device: IOPstim; Device: Suction Cup

• Study Type: Interventional
• Enrollment (Actual): 13
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 33 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Men and women aged between 18 and 35 years
• Non-smokers
• Normal findings in the medical history unless the investigator considers an abnormality to be clinically irrelevant
• Normal ophthalmic findings, ametropia < 1 Dpt.

Exclusion Criteria:

• Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
• Treatment in the previous 3 weeks with any drug (except contraceptives)
• Symptoms of a clinically relevant illness in the 3 weeks before the first study day
• Blood donation during the previous 3 weeks
• Pregnancy, planned pregnancy or lactating

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: IOPstim	Device: IOPstim; IOPstim (IMEDOS, Jena, Germany) is a device exerting defined pressure to the sclera and hence increasing IOP.; Device: Suction Cup; Suction Cup is a device exerting defined suction to the clear and hence increasing IOP

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Intraocular pressure (IOP)	15 Minutes

Collaborators and Investigators

• Sponsor: Medical University of Vienna

Study record dates

Study Major Dates

• Study Start (Actual): July 24, 2019
• Primary Completion (Actual): February 2, 2021
• Study Completion (Actual): February 2, 2021

Study Registration Dates

• First Submitted: August 1, 2019
• First Submitted That Met QC Criteria: August 1, 2019
• First Posted (Actual): August 5, 2019

Study Record Updates

• Last Update Posted (Actual): April 7, 2022
• Last Update Submitted That Met QC Criteria: April 6, 2022
• Last Verified: April 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: OPHT-120219

Drug and device information, study documents

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