Infectious Scleritis

Infectious Scleritis - Fiery Eye Invaders

• Direct microbial invasion of sclera; severe, boring pain, often radiating.
• Signs: Intense, violaceous/fiery redness, photophobia, ↓vision, scleral nodules/abscess.
  • Necrotizing form: Scleral thinning, melt, potential perforation.
• Common Causes:
  • Bacterial: Pseudomonas aeruginosa (post-op/trauma), S. aureus, Streptococci, Nocardia.
  • Fungal: Aspergillus, Candida (post-trauma with vegetative matter).
  • Viral: Herpes Zoster Ophthalmicus (HZO).
• Risk Factors: Ocular surgery (pterygium, >50% cases), trauma, contact lens wear, systemic immunosuppression.
• Diagnosis: Clinical suspicion, confirmed by scleral biopsy & culture (Gram, KOH, special stains).

  ⭐ Pseudomonas aeruginosa is the most common bacterial cause, especially post-surgically, known for aggressive scleral necrosis. oka

Infectious Scleritis - Detective Work Dx

• Presentation: Severe, boring pain (often worse at night, radiates), focal/diffuse redness, photophobia, ↓ vision. Scleral/conjunctival nodules or abscess may be present.

• Key Differentiator: Pain out of proportion to inflammation.

• Diagnostic Approach: High index of suspicion, especially in:

  • Post-surgical cases (cataract, pterygium, SICS, retinal detachment repair)
  • Trauma
  • Adjacent keratitis/endophthalmitis
  • Immunocompromised patients

• Investigations:

  • Scleral scrape/biopsy for microbiology (Gram stain, KOH, culture - blood agar, Sabouraud dextrose agar, non-nutrient agar with E. coli overlay for Acanthamoeba).
  • PCR for specific organisms (e.g., HSV, VZV, Acanthamoeba).
  • B-scan ultrasound: ↑ scleral thickness, fluid in Tenon's space, choroidal detachment.
  • Systemic workup if underlying disease suspected.

⭐ Scleral biopsy is the gold standard for diagnosing infectious scleritis, especially when smears are negative or in atypical presentations.

• 📌 Pain, Photophobia, Purple hue, Poor vision, Potential for Perforation - the 5 Ps of severe scleritis to remember!

Infectious Scleritis - Trouble & Twins

• Severe scleral inflammation by microbes; often unilateral.
• Key Features: Intense, boring pain (radiates, worse at night), redness, photophobia, ↓vision; scleral nodule/abscess.
• Etiology:
  • Bacteria: Pseudomonas aeruginosa (esp. post-op). 📌 Ps: Post-op, Pain, Pus, Progression, Perforation. S. aureus.
  • Fungi: Aspergillus, Candida (post-trauma).
  • Viruses: HZV, HSV.
• Trouble (Complications):
  • Necrotizing form: scleral thinning, melt, perforation, staphyloma.
  • Uveitis, glaucoma, cataract, endophthalmitis, vision loss.
• Twins (Mimics/DDx):
  • Non-infectious (autoimmune) scleritis (common overall).
  • Severe episcleritis.
  • Keratitis extending to sclera.
• Dx: Clinical; scleral scrape/biopsy for microbiology.
• Rx: Aggressive antimicrobials (systemic, fortified topical); debridement. Avoid steroids alone.

⭐ Post-surgical infectious scleritis is often due to Pseudomonas aeruginosa and can lead to rapid scleral melt.

Infectious Scleritis - Quelling the Flames

• Primary Goals: Eradicate infection, control inflammation, preserve vision.
• Initial Management:
  • Prompt hospitalization is key.
  • Scleral biopsy/cultures (ideally before antimicrobials).
  • Commence broad-spectrum systemic (IV) & fortified topical antimicrobials.
  • Cycloplegics for pain relief.
• Pathogen-Specific Therapy (Post-Culture):
  • Bacteria: Targeted antibiotics (e.g., Vancomycin, Ceftazidime).
  • Fungi: Systemic (e.g., Voriconazole) & topical (e.g., Natamycin) antifungals.
  • Viruses (e.g., VZV): Systemic antivirals (e.g., Acyclovir).
• Corticosteroids:
  • Systemic (e.g., Prednisolone 1 mg/kg/day) added cautiously only after 48-72 hours of effective antimicrobial therapy if severe inflammation persists.
  • ⚠️ Avoid topical steroids during active infection.
• Surgical Intervention:
  • For scleral abscess, extensive necrosis, perforation, or non-resolution.

⭐ Pseudomonas aeruginosa is a notorious cause of aggressive, often post-surgical, infectious scleritis.

High‑Yield Points - ⚡ Biggest Takeaways

• Severe, deep, boring pain, often nocturnal, is a hallmark of infectious scleritis.
• Pseudomonas aeruginosa is a key bacterial cause, especially post-surgery or trauma.
• Fungal (Aspergillus) & viral (HZV) causes are also significant.
• Diagnosis needs scleral scraping or biopsy for microbiological confirmation.
• Prompt, aggressive treatment with systemic antimicrobials is essential.
• Can lead to scleral thinning, necrosis, perforation, and irreversible vision loss.
• Presents as nodular, diffuse anterior, or vision-threatening posterior scleritis.