ISOLATION AND IDENTIFICATION OF FUNGAL AGENTS IN PATIENT WITH CORNEAL ULCER IN TERTIARY CARE OPHTHALMIC HOSPITAL

BACKGROUNDThe cornea is usually kept free from microbial invasion due to the intact epithelium and cleansing effect of the tears.Corne al ulceration is defined as any disruption to the intact epithelium with underlying stromal infiltration and suppuration associated with signs of inflammation, the organism either being implanted from without or from the conjunctival flora.Exceptions to the rule are Neisseria gonorrhoeae and Corynebacterium diphtheriae, which are able to invade an intact epithelium.These organisms have the potential to cause microbial keratitis and corneal ulceration, given the appropriate condition and predisposing risk factors.A wide spectrum of microbial organisms like bacteria, virus, fungus and parasite can produce infectious corneal ulcers.The fungal isolates commonly associated with infectious corneal ulceration are Aspergillus species, Penicillium species and Fusarium species.The commonly encountered aetiological agents of fungal corneal ulcers show wide geographical variation.Breakdown of corneal defence mechanism will allow entry of microorganisms to lodge in the corneal stroma.Activation of compliment and release of mycotoxins result in suppurative corneal ulceration. MATERIALS AND METHODSSamples are collected by corneal scraping and examined by KOH mount and direct smear.Further, they were inoculated in SDA for culture.Identification of fungal culture was done by lactophenol cotton blue and slide culture methods. RESULTSA total of 160 patients with infectious corneal ulcer were selected for the study; 97 cases were culture positive (60.6%).Considering the sex distribution, 61 (64.21%) males and 36 (55.38%) female patients showed positive culture.A high prevalence of fungal corneal ulcers was seen among males contributing to 64.21% of cases.Among the fungal isolates, 58 out of 97 (59.7%) cases were due to Aspergillus species and the next common agent isolated was Penicillium species (16.49%) followed by Fusarium species (10.3%),Curvularia species (6.18%), Acremonium species (3.09%) and Candida species (4.12%). CONCLUSIONInfectious fungal corneal ulceration is a sight threatening condition with significant ocular morbidity due to their varied aetiology, unless the aetiological agents are correctly and promptly identified and treatment instituted at the earliest.They can result in permanent damage to the cornea with permanent loss of vision.Precise identification of the causative organisms and timely institution of appropriate fungal therapy based on the prevailing sensitivity pattern of the fungal isolates could save the eye from this preventable cause of blindness.