Bacterial and Fungal Keratitis: Current Trends in Its Diagnosis and Management

Purpose of ReviewInfectious keratitis is the fifth most prevalent cause of blindness worldwide. The primary diagnostic test to identify the pathogenic organism is the culture of corneal scraping. However microbial culture positivity is low and varies widely due to many underlying factors. Therefore, there is a need to understand the prevalence of such cases and what modern tools can be employed to diagnose them.Recent FindingsContact lens usage, ocular injuries, and ocular surface disease have been reported to be primary risk factors for keratitis with infection of pathogens such as Staphylococcus spp., Pseudomonas aeruginosa, Fusarium spp., Candida spp., and Acanthamoeba spp. Advanced imaging techniques, such as in vivo confocal microscopy and anterior segment optical coherence tomography (OCT), and polymerase chain reaction (PCR) and other molecular techniques have been used to identify the specific causative agents of infectious keratitis more rapidly and accurately than traditional culture methods. However, microbial culture positivity is low and varies widely due to many underlying factors.SummaryIn vivo confocal microscopy and polymerase chain reaction (PCR) testing can support the diagnosis of infectious keratitis. Initial treatment for bacterial keratitis (BK) is with antimicrobials primarily fluoroquinolones, while topical natamycin (an antifungal anti-protozoal) is the drug of choice for fungal keratitis. Additionally, PCR and other molecular methods are utilized to corroborate the initial diagnosis or where routine microbial cultures are negative. This review provides current information for diagnosing microbial culture negative keratitis patients. Earlier diagnosis with modern tools could decrease incidence of corneal opacity, vision loss, or even the loss of an eye in keratitis patients.

Automated summary

Infectious keratitis is a major cause of blindness worldwide. Recent studies have found that contact lens usage, ocular injuries, and ocular surface disease are primary risk factors for keratitis. Advanced imaging techniques and molecular detection methods are more effective than traditional culture methods in rapidly and accurately diagnosing infectious keratitis.