Description

• Diseases and abnormalities of tear production and maintenance of tear film
• The most common lacrimal disorder is dry eye syndrome, which is often referred to as dysfunctional tear syndrome.
• Lacrimal duct disorders usually result in overflow tearing.
• System(s) affected: skin/exocrine

Epidemiology

Prevalence
Very common throughout the United States; more often seen in arid climates:

• Predominant gender: female > male
• Predominant age: Dry eye symptoms increase with age and are most often seen in the elderly.

Etiology and Pathophysiology

• Tear film is composed of three layers:
  • Mucin layer: allows spread of aqueous tears
  • Thick aqueous layer: produced by lacrimal gland
  • Lipid layer: controls tear evaporation
• Results from poor tear production, rapid tear evaporation, and/or an abnormal concentration of mucin or lipid in tear film
• Most common cause of dry eye symptoms is aqueous tear deficiency.
• Decreased androgens are thought to contribute to a decrease in tear production.

Risk Factors

• Exposure to dry environments (e.g., high altitudes)
• Contact lenses wear
• Female gender
• Computer use
• Hormonal diseases
• History of collagen vascular disease such as rheumatoid arthritis, Sjögren syndrome, thyroid disease, rosacea, Bell palsy, eyelid abnormalities
• Medications, including oral contraceptives, diuretics, β-blockers, anticholinergics, antihistamines, and antidepressants
• Smoking
• Vitamin A deficiency
• Eye surgery: blepharoplasty, cataract, laser vision correction
• Use of artificial tears (with preservatives)

General Prevention

• Prevent exposure to eye irritants from pollution, cigarette smoke, and sun exposure.
• Ensure adequate vitamin A intake through diet or as a supplement.
• Patients with prior laser vision correction should wait at least 6 months before undergoing blepharoplasty because of the effects on corneal sensation, tear production, and tear film alteration.
• Increasing awareness of this condition among people residing in dry environments
• Decrease or stop contact lens wear.

Commonly Associated Conditions

• Sjögren syndrome
• Rheumatoid arthritis
• Thyroid disease
• Rosacea
• Pregnancy
• Menopause
• Malnutrition