Ocular Microbiome and Immune System in Dry Eyes

Dry Eye Disease Clinical Trial

Official title:

Associations of the Ocular Microbiome and the Immune System in Dry Eye Disease

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04658238
• Other study ID #: BASEC 2020-00775
• Status: Recruiting
• Start date: October 1, 2020
• Est. completion date: December 31, 2026

Study information

• Verified date: December 2023
• Source: Insel Gruppe AG, University Hospital Bern
• Contact: Martin Zinkernagel, Prof. Dr. Dr.
• Phone: +41 31 632 95 65
• Email: martin.zinkernagel[@]insel.ch
• Is FDA regulated: No
• Study type: Observational

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 600
• Est. completion date: December 31, 2026
• Est. primary completion date: December 31, 2026
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Dry Eye Disease
• Dry Eye Syndromes
• Eye Diseases
• Keratoconjunctivitis Sicca

Intervention

Other:
• Ocular microbiome
Taxonomical and functional characterization of the ocular microbiome
• Ocular immune system
Functional characterization of the tear fluid proteome, histology of conjunctival tissue and molecular assays

Locations

Country	Name	City	State
Switzerland	Department of Ophthalmology, Inselspital	Bern

Sponsors (3)

Lead Sponsor	Collaborator
Insel Gruppe AG, University Hospital Bern	Fondation Bertarelli, Stiftung OPOS

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Stability of the ocular surface microbiome	Sequential sample collection of eye swabs	3-6 months after baseline
Primary	Ocular microbiome and local immune system in controls	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.	At baseline
Primary	Ocular microbiome and local immune system in patients	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.	At baseline
Secondary	Differences of the ocular microbiome and the local immune system between patients and controls	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.	At baseline
Secondary	Correlations between the ocular microbiome and the local immune system	Identification of correlations between the ocular microbiome and the local immune system. For variables used see Outcome 3.	At baseline