Potential Role of Ocular Surface Microbiome in Dry Eye: Microbial Interactions and Symptom Alleviation

NCT06936462 | Completed

• 1 other identifier: 2019-01-01
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Study design and sample collection This study is randomized, double-blind, and prospective trial. The inclusion criteria were as follows: patients aged 19 years or older with symptoms of dry eye syndrome. A total of 50 participants were randomly assigned to either the CsA group (n = 25, cyclosporine A twice a day and hyaluronic acid twice daily) or the control group (n = 25, hyaluronic acid four times daily). 0.05% cyclosporine A (Cyporin N Eye Drops, Taejoon Pharm, Republic of Korea) and 0.15% hyaluronic acid (New Hyaluni Eye Drops, Taejoon Pharm) were used in this study. Blinding was maintained by separating the examiner and the sample collector. Exclusion criteria included the use of topical ocular drops or systemic medication (such as systemic steroids, immunomodulators, and tetracyclines) that could influence study outcomes, as well as the presence of conjunctivitis, anterior blepharitis, Demodex infestation, parasitic eye infections, unresolved ocular trauma, healing disorders of the ocular surface (OS), a history of penetrating keratoplasty, contact lens use, or any ophthalmic surgical procedure within three months before baseline. Additionally, subjects with a single functional eye, pregnant or breastfeeding women, and those at risk of pregnancy without contraception were excluded. Clinical data and OS samples were collected at baseline before eye drop administration (V1) and at 4 weeks (V2) and 12 weeks (V3) after treatment initiation (Fig. 1a). Of the 50 participants at V1, 21 participants from each group completed follow-up at V2, while 14 participants in the CsA group and 18 participants in the Newhyaluni group remained at V3. OS samples for microbiome analysis were obtained from the inferior conjunctival sac using sterile mixed cellulose ester (MCF) membrane (Millipore, Merck). OS samples were collected from 13 participants in the CsA group and 13 participants in the Newhyaluni group. All OS samples were stored at -80 °C until DNA extraction for microbiome analysis. Clinical data collection Symptoms were assessed using the Ocular Surface Disease Index (OSDI), Visual Analogue Scale (VAS) for pain, and the modified Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire. Tear film stability was evaluated by measuring the tear break-up time (TBUT). Fluorescein staining of the cornea was performed by applying a drop of sterile saline to a sterile fluorescein strip. After the subject blinked naturally three times, the time between a normal blink and the first appearance of a dry spot in the tear film was recorded. The average of three repeated measurements was used for analysis. OS inflammation was assessed using the fluorescein staining score (FSS) graded according to the Oxford scoring system. The severity of meibomian glands and eyelid inflammation, as well as lid margin hyperemia, was graded as none, mild, moderate, or severe. Tear secretion was measured using the Schirmer strip without anesthesia. A Schirmer strip was placed at the temporal third of the lower eyelid, between the lower palpebral conjunctiva and the lower bulbar conjunctiva. After 5 min, the length of tear fluid absorbed by the strip was measured in millimeters. DNA extraction and whole metagenome sequencing Total DNA was extracted from the collected OS samples using the RNeasy PowerMicrobiome Kit (Qiagen, Inc., Valencia, CA, USA). DNA concentration was measured with a BioPhotometer D30 using a μCuvette G1.0 (Eppendorf, Hamburg, Germany). To eliminate potential contaminants during the experimental process, 12 negative controls were included, comprising sampling membranes, DNA-free water added to the DNA extraction kit, and DNA-free water added to the sequencing library preparation kit. These negative controls were sequenced alongside the 61 OS samples. For whole metagenome sequencing, extracted DNA was fragmented using NEBNext dsDNA Fragmentase (New England Biolabs, Inc., Ipswich, MA, USA). Library preparation was performed with a Swift 2S Turbo DNA Library Kit (Swift Biosciences, Inc., USA) following the manufacturer's protocol. Purification and size selection were conducted using HiAccuBead (AccuGene, San Diego, CA, USA). Index PCR was carried out with the Swift 2S Turbo Combinatorial Dual Indexing Primer Kit (Swift Biosciences, Inc.), followed by additional purification and size selection using HiAccuBead. The library concentration for each sample was quantified using the Qubit™ dsDNA HS Assay Kit (Thermo Fisher Scientific, USA). Equimolar concentrations of each library (4nM) were pooled and sequenced on an Illumina NovaSeq 6000 system (250-bp paired end). Raw sequence data obtained from the NovaSeq system were processed as previously described. Adapter sequences were trimmed, and quality filtering was performed using Trimmomatic. Paired-end sequences were merged using PEAR v.0.9.11. Human-derived sequences in the metagenome data were identified and removed using BBMap with a reference human genome. Taxon

Conditions

Dry Eye Syndrome (DES)

Outcome Measures

Primary Outcomes (1)

• microbiome

  NGS sequencing of microbiome obtained from ocular surface

  Clinical data and ocular surface (OS) samples were collected at baseline before eye drop administration (V1) and at 4 weeks (V2) and 12 weeks (V3) after treatment initiation

Secondary Outcomes (7)

• Ocular Surface Disease Index (OSDI)

  Clinical data were collected at baseline before eye drop administration (V1) and at 4 weeks (V2) and 12 weeks (V3) after treatment initiation.

• Visual Analogue Scale (VAS) for pain

  Clinical data were collected at baseline before eye drop administration (V1) and at 4 weeks (V2) and 12 weeks (V3) after treatment initiation.

• modified Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire

  Clinical data were collected at baseline before eye drop administration (V1) and at 4 weeks (V2) and 12 weeks (V3) after treatment initiation.

• tear break-up time (TBUT)

  Clinical data were collected at baseline before eye drop administration (V1) and at 4 weeks (V2) and 12 weeks (V3) after treatment initiation.

• Fluorescein staining of the cornea

  Clinical data were collected at baseline before eye drop administration (V1) and at 4 weeks (V2) and 12 weeks (V3) after treatment initiation.

Study Arms (2)

CsA group

EXPERIMENTAL

topical cyclosporine A twice a day and hyaluronic acid twice daily

Drug: topical cyclosporine eyedrops and hyaluronic eyedrops

Newhyaluni group

PLACEBO COMPARATOR

topical 0.15% hyaluronic acid (New Hyaluni Eye Drops, Taejoon Pharm) four times a day.

Drug: topical cyclosporine eyedrops and hyaluronic eyedrops

Interventions

topical cyclosporine eyedrops and hyaluronic eyedrops DRUG

topical cyclosporine eyedrops and hyaluronic eyedrops

CsA group; Newhyaluni group

Eligibility Criteria

• Age: 19 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• patients aged 19 years or older
• with symptoms of dry eye syndrome.

You may not qualify if:

• the use of topical ocular drops or systemic medication (such as systemic steroids, immunomodulators, and tetracyclines) that could influence study outcomes
• the presence of conjunctivitis, anterior blepharitis, Demodex infestation, parasitic eye infections, unresolved ocular trauma, healing disorders of the ocular surface (OS),
• a history of penetrating keratoplasty, contact lens use, or any ophthalmic surgical procedure within three months before baseline.
• a single functional eye, pregnant or breastfeeding women, and those at risk of pregnancy without contraception

Sponsors & Collaborators

• Hallym University Kangnam Sacred Heart Hospital: lead

Study Sites (1)

Hallym University, Kangnam Sacred Heart Hospital

Seoul, Seoul, 07441, South Korea

Location

MeSH Terms

Conditions

Dry Eye Syndromes

Condition Hierarchy (Ancestors)

Lacrimal Apparatus Diseases; Eye Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 13, 2025
• First Posted: April 20, 2025
• Study Start: January 20, 2020
• Primary Completion: January 28, 2024
• Study Completion: January 28, 2024
• Last Updated: September 3, 2025

Record last verified: 2025-04

Data Sharing

• IPD Sharing: Will not share

Locations

KR (1)