None listed
Conditions
Brief summary
Corneal nerve disease (neuropathy) can negatively impact quality-of-life due to associated ocular surface disease, which promotes chronic pain and impaired vision, particularly in severe cases. Corneal neuropathy impairs the trophic and sensory functions of the corneal nerves, leading to reduced corneal sensitivity and disruptions to ocular surface integrity. The currently available techniques to measure corneal nerve function and structure are available only in research settings. Moreover, the techniques measuring corneal nerve function are primarily a measure of mechanical corneal sensation and not a composite measure of the corneal sensations. This is a major barrier to early-stage diagnosis and management of corneal neuropathy. So, robust measures of corneal nerve integrity that could be performed routinely in the clinic need to be developed. The main aim of this project is to investigate a new method for assessing corneal nerve integrity. Our approach involves quantifying subjective corneal sensory responses and the interaction between immune cells and nerves in the cornea (using non-invasive corneal imaging) in response to stimulating the cornea with sterile salt solutions. These approaches will be compared between healthy (control) corneas and corneas with nerve changes from LASIK. These findings will provide a foundation for determining whether these aspects of corneal nerve function might have the potential to be used in the future as a marker of corneal neuropathy. The identification of a suitable non-invasive biomarker of corneal nerve fibre integrity has the capacity to be translated into the clinic, for enhanced early detection of corneal nerve damage.
Interventions
Arm 1: Sterile, hyperosmolar saline solution will be repeatedly applied using a pipette and single-use, sterile pipette tip to the surface of the right eye; 10 times, one drop, every 3 minutes for 30 minutes. A member of the research team will administer the saline solutions. Hence, assessing or monitoring adherence to the intervention is not required. Duration of wash-out period: 7 +/- 3 days. Note: Chemically inert eye drops are categorised as ‘medical devices’ by the TGA in Australia.
Sponsors
The University of Melbourne
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Diagnosis
Masking
Blinded (masking used) (Subject, Investigator)
Eligibility
Sex/Gender
All
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
1. Written informed consent and documentation, in accordance with privacy requirements, obtained prior to performing any study procedures in the healthy and post-LASIK population; 2. Ability to understand and follow study instructions, with the intention of completing all of the required study visits in the healthy and post-LASIK population; 3. Distance best-corrected visual acuity of at least 6/9 Snellen equivalent in each eye using a standard visual acuity chart in the healthy and post-LASIK population; 4. Post-LASIK population: participants who underwent LASIK, 6 months to 1 year prior to enrolment, for the correction of myopia;
Exclusion criteria
i) Healthy and post-LASIK population: 1. Females who are currently pregnant or breastfeeding; 2. Diagnosis of a systemic disease known to affect small nerve fibres or the health of the ocular surface; 3. Current, or recent (within last 3 months), use of any agent (by any route of administration) known to substantially affect ocular surface health; 4. Active ocular inflammation, allergy or infection; 5. Any ocular surface condition or history of surgery that may adversely alter corneal nerves; 6. Participants with a scheduled corneal surgery over the course of the study; 7. Known allergy to, or previous reaction to, any agents required to be used for the study; 8. History of chronic migraine ii). Healthy population: Clinically significant dry eye disease, as specified in the TFOS DEWS II definition; iii) Post-LASIK population: Post-LASIK ectasia; history of any surgery, other than a single LASIK surgery, that might affect the health of the ocular surface;
Outcome results
None listed