Dry eye disease (DED) is a common chronic condition characterized by ocular surface discomfort and tear film instability. Evaporative DED associated with meibomian gland dysfunction (MGD) is a frequent phenotype and is often driven by inflammatory mechanisms. This randomized, double-blind, placebo-controlled trial evaluates whether an oral microbiome-focused food supplement improves dry eye symptoms and objective clinical signs compared with placebo over 8 weeks in adults with moderate evaporative DED due to MGD.
Participants with moderate evaporative DED associated with MGD will be randomized 1:1 to receive either a microbiome-focused oral food supplement or matching placebo for 8 weeks. The primary endpoint is change in Ocular Surface Disease Index (OSDI) from baseline to Week 8 and at 16 week follow-up. Key secondary endpoints include changes in tear film breakup time (TBUT), Schirmer I test, and ocular surface staining. Safety and tolerability will be assessed throughout the study. Standard supportive care (e.g., preservative-free artificial tears) will be permitted if kept stable and documented.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
QUADRUPLE
Enrollment
130
Oral food-grade supplement designed to modulate gut microbiome-linked metabolic pathways relevant to ocular surface homeostasis (gut-eye axis). Administered once daily for 8 weeks (e.g., sachet/capsule taken with water).
Matched placebo (appearance, taste/odor, packaging) administered once daily for 8 weeks (oral).
T.C. İstanbul Prof. Dr. Cemil Taşcıoğlu Şehir Hastanesi
Istanbul, Turkey (Türkiye)
Istinye University
Istanbul, Turkey (Türkiye)
Medipol University
Istanbul, Turkey (Türkiye)
Change from baseline in Ocular Surface Disease Index-6 (OSDI-6) total score
The Ocular Surface Disease Index-6 (OSDI-6) is a shortened 6-item patient-reported outcome measure recommended by TFOS DEWS III as the standardized screening questionnaire for dry eye disease. Each item is scored from 0 to 4, and the total score is calculated as the sum of the 6 item scores, yielding a total score range of 0 to 24. Higher scores indicate worse dry eye symptom burden. According to TFOS DEWS III, OSDI-6 scores may be interpreted as follows: 0-3, normal range; 4-8, mild-to-moderate symptom severity; and \>8, severe symptom severity. A score of 4 or higher is considered consistent with a positive symptom screen for dry eye disease. The primary endpoint is the mean change from baseline in OSDI-6 total score at Week 8, corresponding to the end of the intervention period.
Time frame: Baseline to Week 8 (end of treatment)
Change from baseline in Ocular Surface Disease Index-6 (OSDI-6) total score (durability)
The Ocular Surface Disease Index-6 (OSDI-6) is a 6-item, patient-reported symptom questionnaire for dry eye disease. Each item is scored from 0 to 4, and the total score is calculated as the sum of the 6 item responses, yielding a total score range of 0 to 24, with higher scores indicating worse symptoms. The outcome is the mean change from baseline in OSDI-6 total score at the Week 16 follow-up visit to assess durability of symptom response after stopping intervention. TFOS DEWS III classifies OSDI-6 scores as 0-3 normal, 4-8 mild-to-moderate, and \>8 severe.
Time frame: Baseline to Week 16
Change from baseline in Non-Invasive Break-Up Time (NIBUT)
NIBUT (seconds) is a device-based measure of tear film stability obtained without fluorescein dye. The endpoint is mean change from baseline in NIBUT, defined as the average of repeated measurements per protocol (e.g., 2-3 recordings; specify in protocol SOP). Higher values indicate more stable tear film.
Time frame: Baseline to Week 8 and Baseline to Week 16
Change from baseline in conjunctival staining score (Oxford grading scheme)
Conjunctival fluorescein staining will be graded using the Oxford grading scheme. Scores range from 0 to 5, with higher scores indicating more severe ocular surface staining (worse ocular surface integrity). The outcome is the mean change from baseline in conjunctival staining score.
Time frame: Baseline to Week 8 and Baseline to Week 16
Change from baseline in meibum quality score
Meibomian gland function will be evaluated by standardized digital expression of the lower eyelid meibomian glands. Meibum quality will be graded in eight lower eyelid glands using a 4-point ordinal scale (0-3 per gland), where 0 = clear meibum, 1 = cloudy meibum, 2 = cloudy meibum with particulate debris, and 3 = inspissated/toothpaste-like meibum. A composite meibum quality score will be calculated by summing grades across 8 glands (total score range: 0 to 24). Higher scores indicate worse meibum quality (greater gland secretion abnormality). The outcome is the mean change from baseline in composite meibum quality score at the specified assessment time point(s).
Time frame: Baseline to Week 8 and Baseline to Week 16
Change from baseline in meibomian gland dropout score (meibography; SIRIUS)
Non-contact infrared meibography of the upper and lower eyelids will be performed using the SIRIUS device. Meibomian gland dropout will be graded using a pre-specified meiboscore (0 to 3) for each eyelid, where 0 indicates no gland loss and 3 indicates severe gland loss. A total meibography dropout score will be calculated for each eye by summing upper and lower eyelid scores (range 0 to 6), with higher scores indicating worse meibomian gland loss. For each visit, the participant-level value will be the mean of both eyes. The outcome is the mean change from baseline in total meibography dropout score.
Time frame: Baseline to Week 8 (end of treatment) and Baseline to Week 16 (8 weeks post-treatment)
Change from baseline in meibomian gland expressibility score
Meibomian gland expressibility will be assessed by standardized digital expression of five central glands of the lower eyelid. Expressibility will be graded using a 4-point ordinal scale (0-3) based on the number of glands yielding liquid secretion: 0 = all five glands expressible; 1 = three to four glands expressible; 2 = one to two glands expressible; and 3 = no glands expressible. The total expressibility score ranges from 0 to 3. Higher scores indicate worse meibomian gland expressibility (greater gland obstruction/dysfunction). The outcome is the mean change from baseline in meibomian gland expressibility score
Time frame: Baseline to Week 8 and Baseline to Week 16
Conjunctival redness severity (Efron grading scale)
Change from baseline in conjunctival redness severity graded using the Efron Grading Scale for bulbar conjunctival hyperemia. The Efron scale ranges from 0 to 4 (including half grades, if used per protocol), with higher scores indicating greater conjunctival redness (worse hyperemia). The outcome is the mean change from baseline in conjunctival redness score.
Time frame: Baseline (Week 0), Week 8 (End of Treatment), and Week 16 (Follow-up)
Change from baseline in Schirmer I test without anesthesia (mm/5 min)
Schirmer I test without topical anesthesia measures aqueous tear production using standardized paper strips placed in the lower fornix for 5 minutes. Results are recorded in millimeters of wetting (mm/5 min). The outcome is the mean change from baseline in Schirmer I test value. Higher values indicate greater tear production (improved tear secretion).
Time frame: Baseline (Week 0), Week 8 (End of Treatment), and Week 16 (Follow-up)
Change from baseline in rescue artificial tear use (drops/day)
Average number of rescue artificial tear instillations per day recorded by diary or structured recall over a defined window prior to each visit. Lower values indicate reduced need for rescue therapy.
Time frame: Baseline to Week 8 (end of treatment) and Baseline to Week 16 (8 weeks post-treatment)
Incidence of adverse events (AEs) and serious adverse events (SAEs)
Number of participants experiencing any AE/SAE; severity and relatedness assessed by investigator.
Time frame: Baseline through Week 16 (8 weeks post-treatment)
Change in gut microbiome alpha diversity (e.g., Shannon index)
Alpha diversity computed from 16S rRNA sequencing data; change from baseline.
Time frame: Baseline to Week 8
Change in gut microbiome beta diversity (Bray-Curtis distance)
Community structure shift tested via PERMANOVA; within-subject distances summarized.
Time frame: Baseline to Week 8
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.