Dry eye syndrome

Disease Description (Causes and Symptoms)

• Definition: A chronic syndrome (dry eye syndrome) that occurs when the ocular surface becomes dry due to decreased tear secretion or an imbalance in tear components.
• Summary of pathophysiology:
  • The tear film consists of a mucin layer (inner layer), aqueous layer (middle layer), and lipid layer (outer layer). Abnormalities in any layer can lead to tear-film instability, excessive evaporation, and ocular-surface damage.
  • Main mechanisms: (1) decreased aqueous secretion (aqueous-deficient type) — associated with reduced gland function and autoimmune diseases (e.g., Sjögren syndrome), (2) evaporative type — lipid-layer abnormalities caused by meibomian gland dysfunction (MGD), and (3) mixed type.
  • A vicious cycle of chronic inflammation and ocular-surface damage exists (inflammation → tear-film damage → greater dryness).
• Main causes (examples): aging, hormonal changes (such as menopause), systemic diseases (rheumatoid disease, Sjögren syndrome, thyroid disease, diabetes, etc.), medications (anticholinergics, antihistamines, beta-blockers, etc.), environmental factors (dryness, wind, dust, prolonged screen viewing), eyelid disorders (blepharitis, entropion), ocular-surface surgery or radiation damage, etc.
• Main symptoms: foreign-body sensation (gritty feeling), burning, itching, photophobia, eye fatigue, blurred vision, and intermittent excessive tearing. Symptoms tend to worsen in the afternoon and during prolonged near-work activities.

Treatment Methods

• Goals: stabilize the tear film, suppress inflammation, relieve symptoms, and prevent complications (corneal damage).
• Conservative/daily management
  • Artificial tears (frequent use of preservative-free products is recommended) — choose eye drops or gels/ointments (for nighttime use). Select the product format according to symptoms.
  • Environmental control: use a humidifier, avoid wind and smoke, blink frequently, and take regular breaks during screen work (such as the 20/20/20 rule).
  • Eyelid hygiene: warm compresses, eyelid massage, and cleaning around the eyelashes (reduces flakes and bacteria → restores the lipid layer).
  • Assistive devices: moisture goggles or moisture glasses; use gel/ointment instead of eye drops as nighttime support.
• Medication treatment
  • Anti-inflammatory agents: topical cyclosporine (e.g., a 0.05% formulation, by prescription) or lifitegrast (e.g., 5% ophthalmic solution) — used for chronic inflammatory dry eye. It may take several weeks for effects to appear.
  • Short-term topical steroids (low-dose, short-term) — used for a short period in cases of severe inflammation or concern about corneal involvement; long-term use carries risks of glaucoma and cataracts.
  • Antibiotics (oral/topical): in cases of chronic blepharitis or meibomian gland dysfunction, doxycycline-class drugs (e.g., doxycycline) or topical azithromycin may be helpful (as directed by a doctor).
  • Omega-3 fatty acid supplements: may help improve symptoms, but the evidence is inconsistent.
• Device-based/procedural treatment
  • Punctal occlusion (temporary or permanent plug insertion or cauterization) — improves symptoms by reducing tear drainage.
  • Meibomian gland treatment: improved secretion through thermal expression and mechanical massage, IPL (intense pulsed light) treatment, and heat- or vacuum-based devices (such as LipiFlow).
  • Autologous serum tears — used for severe ocular-surface disease.
  • Scleral lenses (protective lenses) and, in severe cases, partial conjunctival closure (tarsorrhaphy), etc.
• Precautions
  • Long-term use of topical steroids increases the risks of glaucoma, cataracts, and infection → use only short-term under the supervision of an ophthalmologist.
  • When wearing contact lenses, some eye drops (those containing preservatives) may increase irritation.
  • If you are taking systemic medications (e.g., antidepressants, antihistamines, diuretics, etc.), consult your doctor.

Outpatient Visit Checklist (Including Suggested Preparations and Questions)

• Items to bring (recommended for hospital visits)
  • A list of all medications currently being taken (including eye drops), recent prescriptions, and medication packages
  • Previous ophthalmic examination results (Schirmer test, TBUT, corneal staining photographs, etc.) or related medical certificates
  • A record of when symptoms began and their patterns of worsening or improvement (time of day, triggering environments)
  • The type of contact lenses being worn and usage habits
  • Medical certificates for systemic diagnoses (autoimmune disease, thyroid disease, diabetes, etc.) and any necessary test results
• Items the doctor is likely to ask about
  • When symptoms began and how they have changed (seasonal or persistent)
  • The amount of tearing (dryness vs. intermittent excessive tearing), and whether pain or decreased vision is present
  • Medication history (especially anticholinergic medications, antihistamines, antidepressants, isotretinoin, etc.)
  • Whether you have had previous ophthalmic surgery (e.g., LASIK) or radiation therapy
• Tests that may be performed during diagnosis (examples)
  • TBUT (tear-film breakup time), Schirmer test, fluorescein/lissamine green staining, eyelid and meibomian gland examination, tear osmolarity, MMP-9 inflammatory marker testing, and meibomian gland imaging (meibography).

General Examples of Questions to Ask the Doctor

• What are the expected effects and side effects of this medication (or treatment)?
• In my case, which type is it (aqueous-deficient vs. evaporative)?
• How long will it take for symptoms to improve? When should treatment be evaluated?
• Will it affect my vision in the long term? What should I do to prevent complications?
• Do the medications I am taking (or other diseases I have) affect dry eye?

Examples of Condition-Specific Questions

• How can you determine whether the dryness in my eyes is evaporative dry eye caused by meibomian gland dysfunction or aqueous-deficient dry eye, and how does the treatment differ?
• If artificial tears are not sufficiently effective, should I start a topical immunomodulator such as cyclosporine or lifitegrast right away? What are the expected effects and side effects?

Additional guidance: If symptoms are severe or are accompanied by decreased vision, severe pain, eye redness, or discharge (pus), seek ophthalmic care immediately.