Description

• Inflammatory or infectious process of the eyelid margin, typically involving skin, lashes, and meibomian glands
  • Associated with itchiness, redness, flaking, and crusting of the eyelids
  • Usually chronic, intermittent with exacerbations and remissions
  • Typically bilateral
  • No universal classification system
• Historically classified according to location, anterior versus posterior
  • Anterior blepharitis: affects the base of the eyelashes and eyelash follicles
  • Posterior blepharitis: affects the meibomian glands
• Can also be classified by etiology
  • Inflammatory: seborrheic, meibomian gland dysfunction, allergic, associated with rosacea
  • Infectious: bacterial (most commonly Staphylococcus aureus or Staphylococcus epidermidis), viral, fungal, or parasitic

Epidemiology

One of the most common ocular disorders (37–47% of patients seen by ophthalmologists and optometrists)

• Presents in patients of all ages
• Mean age of presentation is age 50 years.
• No gender differences seen

Risk Factors

• Presence of atopic, allergic, or seborrheic dermatitis
• Rosacea
• Tear deficiency and dysfunction
• Contact lens use
• Isotretinoin used to treat severe cystic acne
• Less common risk factors include underlying immunologic disorders such as lupus, eyelid tumors, trauma, and other dermatoses.

Pathophysiology

• Multifactorial:
  • Results from the complex interplay between abnormal lid margin secretions, lid margin organisms, and dysfunction of the tear film
• Infectious blepharitis:
  • Bacteria such as Staphylococcus may cause direct infection of the eyelids, evoke reaction to the exotoxin, or provoke an allergic reaction to the staphylococcal antigens.
• Inflammatory blepharitis:
  • Inflammation of the meibomian glands leads to impaired gland secretions and instability of the tear film.
• This condition can have a direct toxic effect and promote bacterial overgrowth.

Etiology

• Complex and poorly understood
• Likely multifactorial
  • Infectious conditions
  • Systemic diseases
  • Environmental factors
• Posterior blepharitis more commonly associated with seborrhea or rosacea

Commonly Associated Conditions

• Seborrheic dermatitis
• Allergic or contact dermatitis
• Down syndrome (trisomy 21)
• Ocular rosacea
• Dry eye (keratoconjunctivitis sicca)
• Hordeolum
• Chalazion