Polymerase chain reaction for early diagnosis of post-operative fungal endophthalmitis.

BACKGROUND AND OBJECTIVES Fungal endophthalmitis is a devastating form of ocular infection and postoperative endophthalmitis following cataract surgery is the commonest form of such infection. Early diagnosis is very important for effective management of these patients. As conventional techniques take longer time and lacks sensitivity, polymerase chain reaction (PCR) for detection of fungal DNA was evaluated for early diagnosis of postoperative fungal endophthalmitis. METHODS Fifty consecutive patients with postoperative endophthalmitis (excluding proven bacterial endophthalmitis) and 25 individuals undergoing pars plana vitrectomy (PPV) of non infectious aetiologies (control group) were included in the study. Aqueous/vitreous fluids, collected from these patients, were evaluated by conventional methods including direct microscopy and culture, and by PCR for detection of fungal DNA using panfungal primers (ITS1 and ITS4) for diagnosis of fungal aetiology. RESULTS None of the controls were positive for fungal aetiology by microscopy, culture or PCR. Four patients were positive for fungal endophthalmitis by conventional method of diagnosis. PCR based method detected fungal DNA in three of these patients and in three additional patients who were negative on microscopy and culture. All six patients, who were positive for PCR, showed clinical improvement after full course of antifungal therapy. INTERPRETATION AND CONCLUSION Compared to the conventional technique, PCR for detection of fungal DNA was found to be a rapid and more sensitive method in the early diagnosis of postoperative fungal endophthalmitis.