Keratoconjunctivitis sicca

Chronic ocular surface disease characterized by deficient tear film causing desiccation, inflammation, and instability of the corneal and conjunctival surface, leading to symptoms of ocular dryness, irritation, and potential epithelial damage.

Causes

• Meibomian gland dysfunction (clogged or dysfunctional oil glands in the eyelids)

• Eyelid abnormalities affecting tear distribution and incomplete eyelid closure

• Aging-related reduction in tear production

  • Hormonal changes after menopause

  • Reduced androgen activity affecting lacrimal and meibomian gland function

• Environmental and behavioral causes

  • Contact lens use

  • Dry climate

  • Air conditioning

  • Smoke exposure

  • Dust and air pollutants

  • Prolonged screen use with reduced blink rate

  • Extended visual tasks requiring sustained attention

• Autoimmune and inflammatory causes

  • Sjögren syndrome

  • Rheumatoid arthritis

  • Systemic lupus erythematosus (SLE)

• Medications reducing tear production or altering tear composition

  • Antihistamines

  • Antidepressants

  • Antihypertensive medications

  • Hormone replacement therapy

• Neurological causes

  • Facial nerve palsy causing impaired eyelid closure

  • Reduced corneal sensation due to trigeminal nerve dysfunction

  • Neurotrophic ocular surface disorders

• Other causes

  • Ocular surgery, including refractive surgery

  • Vitamin A deficiency

  • Radiation therapy affecting lacrimal glands