Investigations for microbial keratitis

• investigating microbial keratitis
  • corneal scrapings for culture and antibiotic testing is usually employed for bacterial keratitis. This should be done before starting antimicrobial therapy if possible.
  • corneal scrapings for Gram stain, Giemsa stain (2)
  • KOH smear (potassium hydroxide wet mount) has a higher sensitivity than Gram stain, Giemsa stain and Kinyoun's acid-fast stain in diagnosis of infective keratitis caused by fungi, Nocardia and Acanthamoeba (1)
  • PCR

Reference:

1. Bharathi MJ et al. Microbiological diagnosis of infective keratitis: comparative evaluation of direct microscopy and culture results. Bharathi MJ Br J Ophthalmol. 2006 Oct;90(10):1271-6.
2. Update on the Management of Infectious Keratitis - Ophthalmology (aaojournal.org) (https://www.aaojournal.org/article/S0161-6420(16)32529-5/fulltext)