Abstract
PURPOSE: To review the use of molecular diagnostic techniques in the management of ocular infectious disease. DESIGN: Retrospective review. METHODS: A combination of literature review and personal recollections are used. RESULTS: Although the broad term molecular diagnostics may encompass techniques to identify pathogens via protein or metabolomic signatures, this review concentrates on detection of pathogen nucleic acid as an indicator of infection. The introduction of the polymerase chain reaction (PCR) in 1985 opened a new era in analysis of nucleic acids. This technique was soon applied to the detection of potential pathogen DNA and RNA, including viruses, bacteria, and parasites in infectious eye disease. Advances in PCR have allowed class-specific diagnostics (ie, pan-bacterial and pan-fungal), quantitation of pathogen DNA, and multiplexed testing. The Human Genome Project in the early 2000s greatly accelerated development of DNA sequencers, ushering in the era of "Next Generation Sequencing" and permitting pathogen-agnostic methods for the detection of potential infectious agents. Most recently, new technologies such as nanopore sequencing have reduced both cost and equipment requirements for whole-genome sequencing; when coupled with real-time sequence analysis methods, these methods offer the promise of true, real-time, point-of-service ocular infectious disease diagnostics. CONCLUSIONS: Molecular methods for pathogen detection have greatly advanced the diagnosis of ocular infectious disease. Further methodologic advances will have a direct impact on the management of these conditions.