What is the management approach for infiltrative disease in the eyes?

Management of Infiltrative Disease in the Eyes

The management of infiltrative disease in the eyes requires a systematic diagnostic approach followed by targeted treatment based on the specific etiology, as infectious and non-infectious causes require fundamentally different therapeutic strategies. 1

Diagnostic Approach

Initial Assessment

• Slit-lamp examination: Evaluate for:
  • Location, density, size, shape, depth, and character of infiltrate margins
  • Presence of epithelial defects
  • Signs of stromal ulceration, thinning, or perforation
  • Anterior chamber reaction (cells, flare, hypopyon)
  • Evidence of previous inflammation or surgery 1

Diagnostic Testing

1. Cultures and smears are indicated when:

   • Infiltrate is central, large (≥2mm), or has significant stromal involvement
   • Multiple corneal infiltrates are present
   • Anterior chamber shows ≥1+ cells
   • History of corneal surgery exists
   • Atypical features suggesting fungal, amoebic, or mycobacterial infection
   • Poor response to empiric therapy 1

2. Advanced imaging:

   • Scanning laser confocal microscopy: Particularly useful for identifying Acanthamoeba, fungal, and bacterial keratitis
   • Optical coherence tomography: Helps determine depth of involvement
   • Ultrasound biomicroscopy: For assessing intraocular structures when severe keratitis is present 1

3. Corneal biopsy when:

   • Response to treatment is poor
   • Repeated cultures are negative despite clinical suspicion
   • Infiltrate is located in mid or deep stroma with overlying uninvolved tissue 1

Differential Diagnosis

Infectious Causes

• Bacterial keratitis: Often suppurative appearance
• Fungal keratitis: Dry appearance, feathered edge, satellite lesions, posterior plaque
• Acanthamoeba keratitis: Ring infiltrate, radial keratoneuritis, severe pain
• Viral keratitis: HSV, VZV, Epstein-Barr virus (may have dendrites or immunologic infiltrates) 1

Non-infectious Causes

• Contact lens-related: Particularly with extended-wear lenses
• Systemic autoimmune diseases: Rheumatoid arthritis, lupus, vasculitic disorders, sarcoidosis
• Dermatologic disorders: Severe ocular rosacea
• Allergic conditions: Vernal keratoconjunctivitis, atopic keratoconjunctivitis
• Trauma-related: Chemical/thermal injury, foreign bodies, exposed sutures 1

Treatment Algorithm

1. Infectious Keratitis

Bacterial Keratitis

• Initial therapy: Broad-spectrum topical antibiotics
  • For small peripheral infiltrates: Fluoroquinolones or combined fortified antibiotics
  • For large/central/sight-threatening infiltrates: Fortified antibiotics (cefazolin + tobramycin/gentamicin)
• Frequency: Every 30-60 minutes initially, then taper based on clinical response
• Adjust therapy based on culture results and clinical response 1

Fungal Keratitis

• Topical antifungals: Natamycin 5% for filamentous fungi, amphotericin B for yeasts
• Consider systemic antifungals for deep or severe infections
• Longer treatment course (weeks to months) typically required 1

Acanthamoeba Keratitis

• Combination therapy: Polyhexamethylene biguanide (PHMB) or chlorhexidine plus propamidine isethionate
• Extended treatment often necessary (3-6 months) 1

Viral Keratitis

• HSV/VZV: Topical and/or oral antiviral agents
• Monitor for superinfection in patients with epithelial defects or severe disease 1

2. Non-infectious Infiltrative Disease

Autoimmune/Inflammatory

• Topical corticosteroids: After ruling out infection
• Systemic immunosuppression: For associated systemic disease or severe cases
• Treat underlying condition if identified 2

Contact Lens-Related

• Discontinue contact lens wear
• Consider prophylactic antibiotics if epithelial defect present
• Patient education on proper contact lens care 1

Monitoring and Follow-up

• Frequent follow-up for all infiltrative disease (daily to weekly initially)
• Document size of infiltrate and epithelial defect at each visit
• Adjust treatment based on clinical response
• Consider corneal biopsy if worsening despite appropriate therapy 1

Prevention Strategies

• Contact lens education: Proper care, avoiding overnight wear
• For therapeutic bandage lenses: Consider prophylactic antibiotics
• Patient awareness of warning signs requiring immediate attention (redness, pain, photophobia)
• Regular follow-up for patients with chronic ocular surface disease 1

Common Pitfalls and Caveats

1. Misdiagnosis: Clinical appearance alone is insufficient to differentiate bacterial from fungal keratitis (correct in <70% of cases) 1

2. Delayed cultures: Obtain cultures before starting antimicrobial therapy for sight-threatening infiltrates

3. Inappropriate steroid use: Never use steroids without ruling out infection first

4. Overlooking systemic disease: Always consider potential systemic associations, especially with bilateral or recurrent infiltrates 2

5. Inadequate follow-up: Infiltrative disease requires close monitoring until resolution

6. Underestimating severity: Central infiltrates or those with anterior chamber reaction require aggressive management 1