Ocular Microbiome and Immune System in Dry Eyes

Sponsor
University Hospital Inselspital, Berne (Other)
Overall Status
Recruiting
CT.gov ID
NCT04658238
Collaborator
Stiftung OPOS (Other), Fondation Bertarelli (Other)
600
1
36
16.7

Study Details

Study Description

Brief Summary

The primary objectives of this study are the characterization of the ocular microbiome as well as of the local immune system in participants with and without dry eye disease. Secondary objectives are the identification of differences in the ocular microbiome as well as in the immune system between participants with and without dry eye disease to ultimately find associations between the ocular microbiome and the immune system in dry eye disease.

Condition or Disease Intervention/Treatment Phase
  • Other: Ocular microbiome
  • Other: Ocular immune system

Detailed Description

Although dry eye disease is considered to be one of the most common ocular surface diseases worldwide, treatment options are only very limited and severe side effects are common. However, recent studies showed that the ocular microbiome may be crucial for maintaining ocular surface homeostasis. Disruption of this homeostasis, called dysbiosis, may lead to inflammation that is a key component in the pathogenesis of dry eye disease. It has been suggested that bacteria are invasive in ocular mucosal tissue, thereby effectively hidden from clearance by the local immune system and rendering the inflammation chronic. Therefore, the investigators hypothesize that the ocular microbiome may induce changes in the mucosal immune system of the eye, which in turn may accelerate the development of dry eyes. Since there is a crucial role of both, the ocular microbiome and the local mucosal immune system, on several diseases, the overall aim of this project is to assess the associations of the mucosal immune system and the ocular microbiome in dry eye disease.

Study Design

Study Type:
Observational
Anticipated Enrollment :
600 participants
Observational Model:
Case-Control
Time Perspective:
Prospective
Official Title:
Associations of the Ocular Microbiome and the Immune System in Dry Eye Disease
Actual Study Start Date :
Oct 1, 2020
Anticipated Primary Completion Date :
Oct 1, 2023
Anticipated Study Completion Date :
Oct 1, 2023

Arms and Interventions

Arm Intervention/Treatment
Dry eye disease

Patients with dry eye disease

Other: Ocular microbiome
Taxonomical and functional characterization of the ocular microbiome

Other: Ocular immune system
Functional characterization of the tear fluid proteome, histology of conjunctival tissue and molecular assays

Healthy controls

Healthy controls without dry eye disease

Other: Ocular microbiome
Taxonomical and functional characterization of the ocular microbiome

Other: Ocular immune system
Functional characterization of the tear fluid proteome, histology of conjunctival tissue and molecular assays

Outcome Measures

Primary Outcome Measures

  1. Ocular microbiome and local immune system in controls [At baseline]

    Qualitative and quantitative characterization of the ocular microbiome and the local immune system in participants with no signs of dry eye disease. The primary variable for the characterization of the ocular microbiome is the identification of microbial taxa and the functional analysis of the identified taxa using eye swabs and conjunctival tissue samples. The primary variable for the characterization of the immune system is the identification of components of the ocular mucosal immune system (i.e. immune cells, anti- and proinflammatory cytokines) using conjunctival tissue samples and tear fluid. Baseline factors such as age, sex, BMI, medication, risk factors for dry eyes such as smoking and contact lenses may have an influence on the ocular microbiome.

  2. Ocular microbiome and local immune system in patients [At baseline]

    Qualitative and quantitative characterization of the ocular microbiome and the local immune system in participants with clinical signs of dry eye disease. For primary variable for characterization see Outcome 1. The variables for grading of dry eyes are tear film osmolarity, split lamp examination, tear secretion and subjective measurement by the "Ocular Surface Disease Index©" (OSDI©)" questionnaire.

Secondary Outcome Measures

  1. Differences of the ocular microbiome and the local immune system between patients and controls [At baseline]

    Identification of differences of the ocular microbiome and the local immune system between patients and controls. The variables used for the differentiation of these two cohorts in terms of the microbiome are the relative abundances of identified microbial taxa and of corresponding functional features (i.e. genes and pathways) of the taxa. The variables used for the differentiation of the cohorts in terms of the immune system are quantitative values of cytokines and immune cells.

  2. Correlations between the ocular microbiome and the local immune system [At baseline]

    Identification of correlations between the ocular microbiome and the local immune system. For variables used see Outcome 3.

Other Outcome Measures

  1. Stability of the ocular surface microbiome [3-6 months after baseline]

    Sequential sample collection of eye swabs

Eligibility Criteria

Criteria

Ages Eligible for Study:
18 Years and Older
Sexes Eligible for Study:
All
Accepts Healthy Volunteers:
Yes
Inclusion Criteria:
  • Willing to sign informed consent

  • 18 years of age or older

Exclusion Criteria:
  • Not willing or able to sign informed consent

  • Younger than 18 years

  • Recent (3 month) history of use of systemic and/or topical antibiotics

  • Usage of medical eye drops (Lacrycon and other moisturizing eye drops are allowed)

  • Recent (3 month) history of ocular surgery

Contacts and Locations

Locations

Site City State Country Postal Code
1 Department of Ophthalmology, Inselspital Bern Switzerland 3010

Sponsors and Collaborators

  • University Hospital Inselspital, Berne
  • Stiftung OPOS
  • Fondation Bertarelli

Investigators

  • Principal Investigator: Martin Zinkernagel, Prof. Dr. Dr., Department of Ophthalmology, Inselspital

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.
Responsible Party:
University Hospital Inselspital, Berne
ClinicalTrials.gov Identifier:
NCT04658238
Other Study ID Numbers:
  • BASEC 2020-00775
First Posted:
Dec 8, 2020
Last Update Posted:
May 20, 2022
Last Verified:
May 1, 2022
Studies a U.S. FDA-regulated Drug Product:
No
Studies a U.S. FDA-regulated Device Product:
No
Keywords provided by University Hospital Inselspital, Berne
Additional relevant MeSH terms:

Study Results

No Results Posted as of May 20, 2022