What is blepharitis?

What is Blepharitis?

Blepharitis is a chronic ocular inflammation that primarily affects the eyelid margins and is a common cause of chronic ocular irritation. 1

Types and Classification

Blepharitis can be classified according to anatomic location:

1. Anterior Blepharitis:

   • Affects the eyelid skin, base of the eyelashes, and eyelash follicles
   • Subtypes include:
     • Staphylococcal blepharitis: Characterized by scaling, crusting, erythema of the eyelid margin, and collarette formation at the base of the cilia
     • Seborrheic blepharitis: Features greasy scaling of the anterior eyelid, often with concurrent seborrheic dermatitis of eyebrows and scalp

2. Posterior Blepharitis:

   • Affects the meibomian glands
   • Also known as Meibomian Gland Dysfunction (MGD)
   • Characterized by terminal duct obstruction and/or changes in glandular secretion

Clinical Presentation

Common Symptoms:

• Redness and irritation
• Burning sensation
• Tearing
• Itching
• Crusting of eyelashes
• Loss of eyelashes
• Eyelid sticking
• Blurring or fluctuating vision
• Contact lens intolerance
• Photophobia
• Increased frequency of blinking
• Recurrent hordeola (styes)

Key Diagnostic Feature:

• Time pattern: Symptoms typically worsen in the morning in blepharitis, whereas symptoms worsen later in the day in aqueous deficient dry eye 1

Physical Examination Findings:

Anterior Blepharitis:

• Scaling and crusting at eyelid margins
• Erythema of eyelid margins
• Collarette formation at base of eyelashes
• Ulcerations (in severe cases)

Posterior Blepharitis/MGD:

• Prominent blood vessels crossing the mucocutaneous junction
• Frothy discharge along eyelid margin
• Pouting or plugging of meibomian orifices
• Thickened meibomian secretions (ranging from turbid fluid to thick cheese-like material)
• Thickening and scalloping of eyelid margin
• Trichiasis (misdirected eyelashes)
• Chalazia

Pathophysiology

Anterior Blepharitis:

• Staphylococcal: Staphylococcus aureus is isolated with greater frequency from eyelids of patients with staphylococcal blepharitis 1
• Bacterial toxins and immune-mediated mechanisms contribute to inflammation
• Enhanced cell-mediated immunity to S. aureus detected in 40% of patients with chronic blepharitis 1

Posterior Blepharitis:

• Decreased availability of normal meibum to lid margin and tear film
• Results in tear film instability and hyperosmolarity
• Often associated with rosacea or seborrheic dermatitis

Natural History and Complications

Blepharitis is typically a chronic condition with periods of exacerbation and remission 1. Although onset usually occurs in middle-aged adults, it can begin in childhood.

Potential complications if left untreated:

• Eyelash loss
• Eyelid scarring with trichiasis
• Corneal involvement:
  • Punctate epithelial erosions
  • Marginal infiltrates
  • Peripheral corneal epithelial defects
  • Corneal neovascularization and scarring
  • Ulceration and perforation (rare, more common in children)

Management Approach

Blepharitis is typically a chronic condition that cannot be permanently cured, and successful management depends on patient compliance with a treatment regimen. 1

First-line Treatment:

1. Lid Hygiene:

   • Warm compresses to soften crusts and meibomian secretions
   • Gentle lid scrubs to remove crusts and debris
   • For blepharitis with crusts and scales, these should be carefully removed before applying any medication 2

2. Topical Antibiotics:

   • Bacitracin ointment applied directly to the conjunctival sac 1-3 times daily 2
   • For blepharitis, spread uniformly over lid margins after removing scales and crusts

3. Combination Therapy:

   • Topical antibiotic-corticosteroid combinations may be effective for addressing both infectious and inflammatory components

For Refractory Cases:

• Oral antibiotics may be considered
• Caution: Oral azithromycin may lead to abnormalities in cardiac electrical activity and potentially serious heart rhythm irregularities in patients with cardiovascular problems 1

Important Clinical Considerations

1. Differential Diagnosis: In patients who do not respond to therapy, consider:

   • Carcinoma
   • Immune-mediated diseases
   • Especially important if blepharitis is associated with eyelash loss and/or conjunctival cicatricial changes 1

2. Special Populations:

   • Children with blepharitis may have higher risk of corneal complications including ulceration and perforation 1
   • Patients with seborrheic blepharitis and MGD are generally older with longer history of ocular symptoms (6.5-11.6 years) 1

3. Monitoring:

   • Regular follow-up to assess treatment response
   • Early diagnosis and appropriate treatment can prevent disfigurement and may be lifesaving in some cases 1

Remember that blepharitis frequently coexists with other ocular surface diseases, making management challenging and often requiring a long-term approach focused on controlling symptoms rather than achieving complete cure.