Use of PCR in endophthalmitis

In eyes with suspected endophthalmitis, early diagnosis and appropriate treatment have been noted to be associated with a better visual outcome. Currently, however, confirmation of the diagnosis of endophthalmitis (bacterial and/or fungal) is dependent on conventional techniques of microbiological isolation of organisms which require between one and twelve days. Furthermore, many samples prove to be culture-negative. In order to improve the rate of microbiological diagnosis, PCR technology has been successfully applied to the detection of bacteria and fungi in ocular samples. Specific oligonucleotide primers have been used to detect the presence of pathogens, which have been subsequently identified using RFLP analysis, DNA sequencing, and/or cloning techniques. Results demonstrated that PCR-based methods are rapidly able to confirm the presence of pathogens with high specificity and sensitivity. PCR-based techniques have also been used to rule out with confidence the presence of pathogens, a unique advantage of this methodology. The use of molecular methods has significantly increased the number of intraocular samples from which a confirmed diagnosis is made and reduced the time to laboratory diagnosis. PCR-based methods promise to be useful diagnostic tools in the management of these patients, especially those from whom ocular samples prove to be culture-negative.