Evaluate the efficacy and safety of ocular surface microbiota transplantation as an adjunctive therapy for dry eye, and explore its impact on the structure of the ocular surface microbiota.

Evaluate the efficacy and safety of ocular surface microbiota transplantation as an adjunctive therapy for dry eye, and explore its impact on the structure of the ocular surface microbiota.

Inclusion Criteria:

• Dry Eye Patient Group:

  • Aged 18 to 70 years, male or female.
  • Meets the diagnostic criteria for moderate to severe mixed dry eye according to the Expert Consensus on Dry Eye (2020), including:
  • At least one subjective symptom (e.g., dryness, foreign body sensation, burning, fatigue, discomfort, redness, or vision fluctuation).
  • Fluorescein tear film break-up time (FBUT) ≤ 5 seconds.
  • Willing and able to actively cooperate with the prescribed course of standard dry eye medications and ocular surface microbiota transplantation therapy for the study duration.
  • Voluntarily agrees to participate and signs the informed consent form.

• Healthy Donor Group:

  • A family member of a participating subject.
  • Aged 18 to 50 years.
  • Normal ocular surface structure and function, with no ocular diseases or related symptoms, and good visual function.

Exclusion Criteria:

• Dry Eye Patient Group:

  • History of systemic chronic diseases (e.g., uncontrolled diabetes, autoimmune disorders).
  • Current or past history of eyelid abnormalities, conjunctival disease, or lacrimal duct obstruction.
  • History of any ocular surgery or regular wear of corneal contact lenses.
  • Active infection in the eye(s) or any other part of the body.
  • History of multiple episodes of viral keratitis or presence of significant neurotrophic keratitis.
  • Any other condition deemed by the investigator to be unsuitable for participation.

• Healthy Donor Group:

  • Known infectious diseases (e.g., HIV, Hepatitis B).
  • Signs or symptoms suggestive of active ocular surface infection or other viral infections.
  • Current or past history of eyelid, conjunctival, or lacrimal duct diseases.
  • Use of systemic medications (including antibiotics), traditional Chinese herbal medicine, or probiotic supplements within 1 month prior to screening.
  • Pregnancy, lactation, or any other condition that may potentially affect the study outcomes.