Clinical trial NCT04658238: Ocular Microbiome and Immune System in Dry Eyes
Official title: Associations of the Ocular Microbiome and the Immune System in Dry Eye Disease
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Dry Eye Disease
Keywords: microbiome
immune system
Lead sponsor: Insel Gruppe AG, University Hospital Bern
Sponsor class: OTHER
Collaborators: name: Stiftung OPOS
name: Fondation Bertarelli
First posted: 2020-12-08
Enrollment: 600
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Consecutive ongoing recruitment of subjects attending routine follow-ups through the involved investigators in daily clinical practice at Department of Ophthalmology, Inselspital, Bern

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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Ocular microbiome and local immune system in controls
timeFrame: At baseline
measure: Ocular microbiome and local immune system in patients
timeFrame: At baseline
Secondary outcomes:
measure: Differences of the ocular microbiome and the local immune system between patients and controls
timeFrame: At baseline
measure: Correlations between the ocular microbiome and the local immune system
timeFrame: At baseline
Other outcomes:
measure: Stability of the ocular surface microbiome
timeFrame: 3-6 months after baseline
Locations:
city: Bern
country: Switzerland
facility: Department of Ophthalmology, Inselspital
Study officials:
affiliation: Department of Ophthalmology, Inselspital
name: Martin Zinkernagel, Prof. Dr. Dr.
role: PRINCIPAL_INVESTIGATOR
References: