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NCT Number: NCT07363824

A Study on the Correlation Between Tear Iron Levels and the Severity of Dry Eye Disease.

This study aims to see if the amount of iron in tears is linked to how severe dry eye disease is. We hope this can lead to a new way to help diagnose and understand dry eye. This is an observational study. We will compare tear samples from people with dry eye to samples from people with healthy eyes. We will measure the iron content in the tears and see if it correlates with standard dry eye test results and symptom scores.

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Key information

Conditions

Dry Eye Disease Dry Eye Syndromes Eye Diseases Iron Lacrimal Apparatus Diseases

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Aged between 18 and 70 years, inclusive.
  • Willing and able to provide written informed consent.

Exclusion criteria

  • History or clinical suspicion of significant systemic conditions: hematologic diseases, severe systemic infections, malignancies (treated or untreated), or chronic hepatic/renal insufficiency.
  • Use of artificial tears or any topical eye drops within 2 hours prior to examination.
  • Active ocular allergy, infection, or severe blepharitis within the past 1 month.
  • Systemic or topical use of antibiotics, corticosteroids, NSAIDs, or immunosuppressants within the past 1 month.
  • History of contact lens wear within the past 1 month.
  • History of blood transfusion, ocular surgery, or significant ocular trauma within the past 6 months.
  • Women who are pregnant, breastfeeding, or postmenopausal women undergoing hormone replacement therapy.
  • Known hypersensitivity to fluorescein sodium.

Treatment and study plan

Diagnostic tear fluid collection and ocular surface evaluation

Procedure

This is an observational study; no therapeutic intervention is administered. All participants undergo a single, standardized study visit that includes:

Tear Fluid Collection: Tear samples are collected using sterile Schirmer test strips (without anesthesia) placed in the lower conjunctival sac for 5 minutes.

Comprehensive Ocular Surface Evaluation:

Symptom Assessment: Completion of the Ocular Surface Disease Index (OSDI) questionnaire.

Clinical Tests: Measurement of fluorescein tear film breakup time (FBUT), corneal fluorescein staining (CFS) scoring, and Schirmer I test.

The collected tear samples are subsequently analyzed for iron concentration. All procedures are diagnostic and evaluative in nature.

Primary outcomes

  1. Correlation between tear fluid iron concentration and dry eye symptom severity

    Time frame: baseline

    The strength of association between the concentration of iron (in μg/mL) in tear fluid collected via Schirmer strips and the total score on the Ocular Surface Disease Index (OSDI) questionnaire.

Secondary outcomes

  1. Correlation between tear fluid iron concentration and tear film stability

    Time frame: baseline

    The correlation between tear iron concentration and fluorescein tear film breakup time (FBUT) measured in seconds.

  2. Correlation between tear fluid iron concentration and tear secretion volume

    Time frame: baseline

    The correlation between tear iron concentration and the result of the Schirmer I test (without anesthesia) measured in millimeters of wetting over 5 minutes.

  3. Correlation between tear fluid iron concentration and corneal epithelial damage

    Time frame: baseline

    The correlation between tear iron concentration and the Corneal Fluorescein Staining (CFS) score, a standardized clinical grading of epithelial damage.

Sponsors and collaborators

Lead sponsor

Shanghai Changzheng Hospital

Other

Registry information

Important dates

Study start
2026
Primary completion
2029
Study completion
2029
First posted
Jan 23, 2026
Registry last updated
Feb 10, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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