Objectives: Fungal aetiology of keratitis ulcer is considered to be one of the leading causes of ocular morbidity, particularly in developing countries including India. More importantly, Fusarium and Aspergillus spp. are reported commonly implicating corneal ulcer and against this background the present work was undertaken so as to understand the current epidemiological trend, clinical profile and outcome of fungal keratitis.
Methods: During the study period (2013-2016), the clinical and mycological characteristics of fungal keratitis was investigated. Our aim was to discuss the predisposing factors, clinical manifestations, and epidemiological characteristics of the causative agents and describe the management strategies that have a high probability of successfully treating this disease. The corneal scrapings were processed by direct microscopic methods and standard culture techniques. All the samples were inoculated onto Sabouraud dextrose agar (SDA), potato dextrose agar (PDA), brain- heart infusion based blood agar in the form of a “C” streak. The SDA and PDA plates were incubated at 30°C for 7 days, and the other plates were incubated at 37°C for 7 days.
Results: A Total of 143 corneal scrapings from keratitis were processed, 72 (50.3%) revealed growth, of which 60 were culture positive for fungi and 12 were culture positive for bacteria. Direct microscopy revealed hyphae or budding yeasts or fungal elements in 60 cases. Among fungal aetiologies, Aspergillus spp. (51.7%) and Fusarium spp. (16.7%) were predominantly determined. The spectrum of mycotic keratitis cases was: Aspergillus flavus (15), A.fumigatus (12), Fusarium solani (5), Fusarium oxysporum (3), Curvularia lunata (3), C. tropicalis (3), C. parapsilosis (2), Fusarium dimerum (2), Paecilomyces lilanicus (2), Alternaria alternata (2), A.terreus (2), A. tetrazonus (1), A.niger (1), Bipolaris (1), Candida krusei (1), Schizophilum commune (1), Scedosporium apiospermum (1), Chryseosporium keratinophillum (1), C. tropicalis (1) and Scytalidium dimidiatum (1). Of the 60 mycotic keratitis male preponderance was seen in 66.66%. Predisposing factors included trauma with vegetative material (98.66%), contact lens use (1.66%), and bird feather hit (1.66%). Pain, redness of eye and dimunition of vision was most common clinical complaints. Steroids and inflammatory drugs were most common pretreatment medication taken. The corneal examination revealed central corneal ulcer with feathery margins, a paracentral superficial ulcer; a central ulcer with an irregular edge, satellite infiltrations, and hypopyon etc. Majority of the patients were given natamycin eye drop alone. Concomitant systemic antifungals and supportive surgical intervention was done in 4 and three cases respectively. Complete loss of vision was seen in one eye was seen in single case.
Conclusion: Our study suggests that mycotic keratitis caused by Aspergillus spp. especially A. flavus may occur more often in a tropical climate, such as in Delhi, India. Aetiological agents other than Aspergillus species and Fusarium species have shown an upward trend. A combination of antifungal therapy and supportive surgical intervention may successfully resolve the mycotic infection Proper understanding of microbiological and clinical characteristics of keratomycosis will enable ophthalmologist to avoid unnecessary and indiscriminate use of steroids or antimicrobials.Early stage of diagnosis and formulation of an uncompromising management protocol can prevent profound visual morbidity.
Full conference title:
- TIMM (2019)