Microbiota, Ocular Surface
Conditions
Keywords
Ocular surface microbiome, Anesthesia, Extraction protocol
Brief summary
The use of anesthetics and the processing of the retrieved samples are major confounding factors that influence the results of microbiome research.
Detailed description
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.
Interventions
DIAGNOSTIC_TESTConjunctival swab
Swab of the conjunctival fornices of both eyes
DRUGOxybuprocaine Hydrochloride 0.4% Eye Drops
One drop of topical anesthesia in one eye
DRUGartificial tears
One drop of artificial tears in the other eye
Sponsors
Universitaire Ziekenhuizen KU Leuven
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DIAGNOSTIC
Masking
DOUBLE (Caregiver, Investigator)
Masking description
The nurse application the drops receives a closed envelope wherein the information about which eye receives what type of drop is included. The executor is blinded.
Intervention model description
When the patient is under general anesthesia for another reason, he or she receives a drop of artificial tears in one eye and a drop of anesthetic in the other eye in a randomized way.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference in richness of the microbial flora measured as operational taxonomic units | 5 minutes per sampling session | 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. |
| Difference in evenness of distribution of the microbial flora measured as operational taxonomic units | 5 minutes per sampling session | 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. |
Countries
Belgium
Outcome results
None listed