With the widespread use of digital devices and prolonged screen exposure, digital eye strain (DES), also known as computer vision syndrome, has become a global public health concern. Emerging evidence suggests that the gut-eye axis may play an important role in ocular health, as gut microbiota imbalance is associated with systemic inflammation and oxidative stress. Specific probiotics may help alleviate eye discomfort through modulation of immune responses and enhancement of antioxidant defense mechanisms. This randomized, double-blind, placebo-controlled study aims to evaluate the efficacy of supplementation with specific probiotics, Bifidobacterium longum BL531 and Lactobacillus reuteri LR1349, in improving digital eye strain symptoms in adults.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
150
Maltodextrin
1×10\^10 cfu/day
2.5×10\^10 cfu/day
1×10\^10 cfu/day
2.5×10\^10 cfu/day
National Taiwan Normal University
Taipei, Taiwan
Computer Vision Syndrome Questionnaire (CVS-Q)
The CVS-Q is a questionnaire used to assess digital eye strain associated with prolonged digital screen use. It includes 16 symptoms related to screen exposure. Total scores are classified as 0-5 (none/minimal), 6-12 (mild), 13-18 (moderate), and ≥19 (severe), with scores ≥6 indicating clinically significant digital eye strain.
Time frame: Baseline, Week 6, Week 12
Ocular Surface Disease Index (OSDI)
The Ocular Surface Disease Index (OSDI) is a 12-item questionnaire used to assess the severity of dry eye symptoms and their impact on vision-related function and daily activities. Total scores range from 0 to 100, with higher scores indicating greater symptom severity.
Time frame: Baseline, Week 6, Week 12
Basic vision examination
A comprehensive ophthalmic examination will be performed, including uncorrected distance and near visual acuity, automated refraction, presbyopia assessment, distance and near vision correction, intraocular pressure measurement, and external eye photography for conjunctival hyperemia assessment.
Time frame: Baseline and Week 12
Pupillary Response Test
Pupillary response testing will be performed using the Oculus Pentacam HR or an equivalent device to evaluate pupil size and response time under light and dark conditions. This assessment provides information on the visual system's adaptation to changes in illumination.
Time frame: Baseline and Week 12
Tear Secretion Assessment
Tear meniscus height will be measured using the OS1000 Corneal Topographer (SBM sistemi, Italy) or an equivalent device as an indicator of tear secretion.
Time frame: Baseline and Week 12
Non-Invasive Tear Break-Up Time (NIBUT)
Non-invasive tear break-up time (NIBUT) will be measured using the OS1000 Corneal Topographer (SBM sistemi, Italy) or an equivalent device to evaluate tear film stability. A shorter NIBUT is commonly associated with dry eye symptoms and digital eye strain.
Time frame: Baseline and Week 12
Corneal Tomography and Topography Analysis
Corneal tomography and topography analysis will be performed using the Oculus Pentacam HR or an equivalent device to evaluate corneal morphology, curvature, thickness, and regularity.
Time frame: Baseline and Week 12
Accommodative Function Assessment
Accommodative function will be assessed using the ARK-1s Auto Ref-Keratometer (NIDEK, Japan) or an equivalent device to evaluate the eye's focusing ability and quantify accommodative responses associated with ciliary muscle contraction and relaxation.
Time frame: Baseline and Week 12
Worth Four Dot Test
The Worth Four Dot Test will be used to assess binocular vision and fusion ability by evaluating responses to red and green visual targets, including the presence of suppression or diplopia.
Time frame: Baseline and Week 12
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