Dry Eye Symptom Mitigation by Oral Intake of Probiotics

This study investigates whether the oral intake of a probiotics capsule product may relieve dry eye symptoms. Participants will be aged between 20 - 65 years of age, with confirmed diagnosis of dry eye status. The participants will be assessed for several parameters and asked to take 1 probiotics capsule per day for 35 days. The parameters will include ocular surface health, tear volume, tear quality, intraocular pressure, tear osmolarity and serum biochemical test. After the 35 days are completed, the participants will be assessed again for the same parameters.

This investigation is a randomized, double-blind study. Subjects with confirmed diagnosis of dry eye are randomly assigned to control group or treatment group, and asked to orally intake 1 capsule of either placebo or probiotics per day. All participants will be assessed for parameters, including intraocular pressure, ocular surface health, tear film breakup time (TBUT), tear volume (Schirmer's test), tear osmolarity, ocular surface impression cytology, ocular surface disease index (OSDI) and serum biochemical tests for quantification of hyaluronic acid, sialic acid, glutathione contents.The assessments are conducted at day1 for baseline and after the 35-day oral intake. The parameters are used to compare and evaluate whether the probiotics can relieve dry eye symptoms.

A specific probiotics capsule product, containing Streptococcus thermophilus will be given to participants for oral intake for 35 days.

A specific capsule product, containing microcrystalline cellulose will be given to participants for oral intake for 35 days.

The Schirmer's Test is used to assess tear secretion volume. The amounts of tears are measured in total millimeters after 5 minutes has elapsed. Lower measurement amount is regarded as a parameter of presence of dry eye disease.

Tear Break-Up Time is a measurement to reflect tear quality and is expressed in seconds. The shorter the Tear Break-Up Time, the poorer the tear film stability and quality. Lower measurement outcome (less than 10 seconds) is regarded as a parameter of presence of dry eye disease.

Ocular Surface Index is assessed with fluorescein staining to reflect ocular surface damages. The staining scale ranges from 0 to 3, from milder to severe status, where grade 0 shows no staining, and grade 3 shows extensive staining.

To determine the effects of oral probiotics intake on the contents of hyaluronic acid, sialic acid, and glutathione in the serum.

A questionnaire is used to assess the health status on ocular surface, with higher scores indicating more severe status.

Inclusion Criteria: aged between 20 and 65 years with Schirmer's test results less than 10 mm or Ocular Surface Disease Index more than 25 Exclusion Criteria: evident ocular diseases such as cornea disease, cataract, vitreous degeneration, glaucoma, and retinopathy. diabetes hypertension or other chronic diseases or belong to vulnerable groups(pregnancy woman, prisoner, ethical minorities, economic or educationally disadvantaged subjects, disabled individuals such as those at terminal stage of tumorigenesis, blindness, terminal ill individuals)

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