Optimization of Sampling and Processing of Samples for Molecular Microbial Research on Ocular Surface Samples

N/ACompletedNCT04193774

Universitaire Ziekenhuizen KU Leuven24 enrolled

Overview

The use of anesthetics and the processing of the retrieved samples are major confounding factors that influence the results of microbiome research.

The use of anesthetics is subject of discussion in ocular surface microbiome research. One publication showed a significant lower alpha diversity when using an anesthetic. However, the diluting effect of the anesthetic drop itself was not accounted for. On the other hand, using anesthetics will enable patients to tolerate sampling better and this might allow better sampling. To analyze the effect of anesthetic drops on the composition of the ocular surface microbiome, we sampled volunteers undergoing general anesthesia. By using artificial tears as a control, we aimed at accounting for the diluting effect of the anesthetic. By using volunteers under general anesthesia, we wanted to assure similar pressure with or without topical anesthesia since the executor was not influenced by the patient's reaction. Furthermore, the effect of different extraction protocols on sequencing results will be assessed by sampling different volunteers in both eyes on non consecutive days.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

DOUBLE

Enrollment

Conditions

Microbiota Ocular Surface

Interventions

Conjunctival swabDIAGNOSTIC_TEST

Swab of the conjunctival fornices of both eyes

Oxybuprocaine Hydrochloride 0.4% Eye DropsDRUG

One drop of topical anesthesia in one eye

artificial tearsDRUG

One drop of artificial tears in the other eye

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Willing to undergo sampling of the conjunctiva * Fluent in written and verbal Dutch * Capable of giving informed consent Exclusion Criteria: * Allergy to oxybuprocaine * Medication usage in one eye only

Locations (1)

University Hospitals Leuven, Department of Ophthalmology

Leuven, Belgium

Outcomes

Primary Outcomes

Difference in richness of the microbial flora measured as operational taxonomic units

The difference in richness and evenness of distribution of the microbial flora of samples retrieved after a drop of topical anesthesia versus samples retrieved after a drop of artificial tears.

Time frame: 5 minutes per sampling session

Difference in evenness of distribution of the microbial flora measured as operational taxonomic units

The effect of the different microbial DNA extraction protocols on the richness and evenness of distribution of the microbial flora of the ocular surface will be compared.

Time frame: 5 minutes per sampling session

Data from ClinicalTrials.gov

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