PCR detects fungal DNA in keratitis

October 23, 2012

Polymerase chain reaction (PCR) could be used to diagnose fungal keratitis.

Polymerase chain reaction (PCR) could be used to diagnose fungal keratitis, claims an investigation in the journal Eye.

A team led by Dr N. Tananuvat, Department of Ophthalmology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, conducted a prospective nonrandomized study on 30 eyes of 30 patients with presumed fungal keratitis.

Each patient underwent corneal scraping and fungal-specific primers were used to analyse the specimens. PCR products were cloned and sequenced and compared to conventional microbial work-up.

PCR demonstrated positivity in 93.3%, culture in 40% and potassium hydroxide in 20% of the total patients included in the study. Out of the 28 PCR-positive patients, 12 were culture-positive and 16 were culture-negative.

There were no false-negative results in the culture-positive specimens recorded by the PCR, suggesting it is able to accurately detect fungal DNA in a high percentage of culture-negative cases. The procedure could be helpful, in addition to smear and culture in the efficient diagnosis of fungal keratitis.

Please click here to read the abstract.