Diagnosing corneal infections in formalin fixed specimens using next generation sequencing

DNA extracted from 16 cases of infectious keratitis, as well as 4 control corneas with no known infection, was sequenced to detect pathogenic and non-pathogenic organisms. All specimens were formalin fixed, routinely processed and paraffin embedded tissues which had undergone standard microscopic analysis in the ophthalmic pathology laboratory. Infectious cases were also analyzed in the microbiology laboratory using culture, polymerase chain reaction and direct staining to establish a diagnosis.