Comparative evaluation of conventional and molecular techniques for the diagnosis of ocular fungal infections

External ocular fungal infections are among the leading causes of ocular morbidity and blindness in developing countries. Advances in microbiological techniques have made it possible not only to understand the pathogenesis of these infections but also develop better diagnostic methods. To determine the incidence and microbiological profile of ocular fungal infections at a tertiary care centre. To assess the utility of Polymerase Chain Reaction in diagnosing ophthalmic fungal infections. Study was done over a period from November 2014 to April 2016. A total of 50 samples were collected was. Various other ocular samples werecollected which were subjected to conventional tests that included 10%KOH examination and fungal culture on SCA, SDA culture media and molecular tests that included Pan fungal Polymerase Chain Reaction. The statistical tests applied were: Senstivity, Specificity, Positive predictive value, Negative predictive value. Out of 50 patients included in this study maximum number of patients were under age group 31–45 years which comes out to be 32%. As compared to females 18(36%) there was clear cut male preponderance 32(64%). Maximum patients gave the history of ocular trauma with a vegetable matter, or any other foreign body which was 25 out of 50 (50%). 14(28%) were shown to be KOH positive, 28(56%) were fungal culture positive, 42(84%) were PCR positive Fusarium species13(47%), followed by A. flavus 5(18%), A. fumigatus 4(14%), Curvularia 4(14%) were the commonest filamentous fungi isolated. While candida was the most frequently isolated yeast. On performing the comparative evaluation between culture(gold standard) and KOH it was seen that the sensitivity and specificity of KOH was 46.4% and 95.4% respectively. While its PPV and NPV was 92.8% and 58.3%. On further comparing culture with PCR sensitivity and specificity of PCR came out to be 100% and 36.36% respectively. While its PPV and NPV was 66.6% and 100%. Culture of fungus remains gold standard for making the diagnosis. KOH examination is a cheaper and less labour intensive method. But the isolation rate of fungus in KOH is very less as compared to culture and molecular method. Culture of fungus is cheaper and more widely available method but is less sensitive than PCR in terms of fungal isolation rate as well as turn aroundtime. Molecular method like PCR though costly but it reduces the time to detect the fungal element (results will come in one day). This is essential for early initiation of right therapy for checking the permanent deformity of eye like blindness.