Nocardia keratitis: A clinical diagnosis with successful outcome

Area of Science:

• Ophthalmology
• Infectious Diseases
• Microbiology

Background:

• Nocardia keratitis is an uncommon ocular infection often challenging to diagnose due to its chronic, fluctuating course.
• Risk factors include alcoholism, malnutrition, and HIV, but it can occur in immunocompetent individuals.
• Early and accurate diagnosis is crucial for effective management and preventing vision loss.

Observation:

• A 53-year-old male presented with a 3-week history of right eye pain and redness.
• Clinical examination revealed a paracentral corneal ulcer with stromal infiltrates and satellite lesions, forming a characteristic wreath-like pattern.
• Microscopic examination of corneal scrapings showed filamentous, branching Gram-positive bacteria, confirmed as acid-fast.

Findings:

• Gram stain and Ziehl-Neelsen staining confirmed the presence of Nocardia species, supporting the clinical diagnosis.
• Treatment with fortified amikacin, moxifloxacin, and cycloplegics resulted in complete resolution of the corneal ulcer within 6 weeks.
• The microbiological findings were essential in confirming the diagnosis and guiding therapy.

Implications:

• This case highlights the importance of maintaining a high index of clinical suspicion for Nocardia keratitis, especially with atypical presentations.
• Prompt microbiological diagnosis is critical for initiating appropriate, sight-saving treatment.
• Effective management relies on a combination of clinical acumen and laboratory confirmation for successful outcomes in Nocardia keratitis.