Investigation in Corneal Sensation

NCT04045509 | Completed

• 1 other identifier: 2019-01252
• Study Type: interventional
• Target: 90
• Locations: 1 country
• Sites: 1

Brief Summary

The aim is to find out more about how corneal sensory fibres react to different types of stimuli (liquid / tactile / nylon thread) and how this can be consciously perceived by the individual. Is it possible to generate a stimulus that delivers a repeatable and reliable response within a useful stimulus force range which allows an interpretation / evaluation of normal / expected activity of superficial nerve fibres in the cornea? The study group will be divided into two age groups, as sensitivity changes are thought to occur in dependence of age. In vivo confocal microscopy has shown that the density of corneal nerve fibres in the sub-basal nerve plexus decreases with age, which consequently would suggest that sensitivity should also decrease. A very interesting research question is to find out, if such sensitivity differences can be detected with the nature of the stimuli applied in this study.

Conditions

Cornea; Sense Loss

Keywords

corneal sensation; subbasal nerve plexus

Outcome Measures

Primary Outcomes (3)

• Repeatability of mechanical corneal sensation thresholds with the Cochet Bonnet esthesiometer

  Evaluation of repeatability of mechanical corneal sensation thresholds for the measurement with the Cochet Bonnet instrument (in mN): the corneal sensation thresholds will be obtained with the double staircase method (with forced choice) and the stimulus represents a nylon thread, whereby its force is proportional to the length of the nylon thread applied to the corneal surface.

  two weeks

• Repeatability of mechanical corneal sensation thresholds with the liquid jet protoype esthesiometer

  Evaluation of repeatability of mechanical corneal sensation thresholds for the measurement with the liquid jet esthesiometer prototype instrument (in mbar): the corneal sensation thresholds will be obtained with the double staircase method (with forced choice) and the stimulus represents a liquid jet (consisting of isotonic saline solution).

  two weeks

• Repeatability of mechanical corneal sensation thresholds with the tactile prototype esthesiometer

  Evaluation of variability / repeatability of mechanical corneal sensation thresholds for the measurement with the tactile esthesiometer prototype instrument (in mN): the corneal sensation thresholds will be obtained with the double staircase method (with forced choice) and the stimulus represents a small, round plastic ball.

  two weeks

Secondary Outcomes (9)

• Correlation between corneal sensation thresholds with the Cochet Bonnet esthesiometer

  one day

• Correlation between corneal sensation thresholds with the liquid jet prototype esthesiometer

  one day

• Correlation between corneal sensation thresholds with the tactile prototype esthesiometer

  one day

• Correlation between corneal sensitivity thresholds, obtained with the Cochet Bonnet esthesiometer, and general pain perception

  within two weeks

• Correlation between corneal sensitivity thresholds, obtained with the liquid jet prototype esthesiometer, and general pain perception

  within two weeks

Study Arms (2)

Group 'young age'

OTHER

Group 'young age': 18 - 30 years of age; healthy eyes

Device: Liquid Jet Esthesiometer Prototype; Device: Tactile Esthesiometer Prototype; Device: Cochet Bonnet esthesiometer

Group 'advanced age'

OTHER

Group 'advanced age': 50 - 70 years of age; healthy eyes

Device: Liquid Jet Esthesiometer Prototype; Device: Tactile Esthesiometer Prototype; Device: Cochet Bonnet esthesiometer

Interventions

Liquid Jet Esthesiometer Prototype DEVICE

Balanced salt solution with a pH value similar to the tear film uesd as a liquid jet stimulus for corneal sensation threshold measurement

Group 'advanced age'; Group 'young age'

Tactile Esthesiometer Prototype DEVICE

A round plastic nozzle (1.8mm diameter) used as a stimulus for corneal sensation threshold measurement

Group 'advanced age'; Group 'young age'

Cochet Bonnet esthesiometer DEVICE

A nylon thread (0.12mm diameter) used as a stimulus for corneal sensation threshold measurement

Group 'advanced age'; Group 'young age'

Eligibility Criteria

• Age: 18 Years - 70 Years
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Group 'young age': 18 - 30 years of age; healthy eyes with Ocular Surface Disease Index Score \</= 13
• Group 'advanced age': 50 - 70 years of age; healthy eyes with Ocular Surface Disease Index Score \</= 13

You may not qualify if:

• Systemic disease that may affect ocular health, such as diabetes
• Injury and history of operations on the anterior segment of the eye
• regular application of systemic or ocular medication known to affect the tear film, specifically on the day of measurement
• rigid gas permeable contact lens wear
• soft contact lens wear less than 48 hours before study visit

Sponsors & Collaborators

• Daniela Nosch: lead

Study Sites (1)

Institute of Optometry, FHNW

Olten, Canton of Solothurn, 4600, Switzerland

Location

Related Publications (1)

• Nosch DS, Kaser E, Bracher T, Joos RE. Clinical application of the Swiss Liquid Jet Aesthesiometer for corneal sensitivity measurement. Clin Exp Optom. 2024 Jan;107(1):14-22. doi: 10.1080/08164622.2023.2191782. Epub 2023 Apr 5.

  PMID: 37019837 DERIVED

MeSH Terms

Conditions

Corneal Diseases

Condition Hierarchy (Ancestors)

Eye Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Clinical Professor

Study Record Dates

• First Submitted: July 30, 2019
• First Posted: August 5, 2019
• Study Start: September 1, 2019
• Primary Completion: November 30, 2019
• Study Completion: November 30, 2019
• Last Updated: December 6, 2019

Record last verified: 2019-12

Locations

CH (1)