Diagnosing Corneal Infection

Microbial keratitis is a common and serious eye disease in Edinburgh. Prompt treatment with antibiotics can prevent sight loss, and identification of the micro-organism and its antibiotic sensitivities are key to appropriate management. Standard practice of collecting infected material from the cornea using a blade can be distressing and time-consuming. Corneal impression membranes (CIM) have recently been introduced to another National Health Service (NHS) eye unit (St Paul's Eye Unit, Liverpool) as they detect more micro-organisms and are more patient-friendly than corneal scrape. The aim of this study is to compare CIM with reference to current standard practice of corneal scrape. If CIM have greater sensitivity and fewer adverse events than scrape then the investigators will consider using CIM instead of scrape in routine clinical care. The investigators will also collect additional CIM to help develop new microbiological tests being developed at the University of Edinburgh, which if successful could be applied to CIM at the bedside to further improve the speed of diagnosis in the future. Development of the new microbiological tests is facilitated by having samples of germs from eye infections. Study design: cross-sectional study comparing diagnostic techniques Participants: recruited from the Acute referral clinic at the Princess Alexandra Eye Pavilion, or emergency on-call ophthalmology service What is involved: subjects with microbial keratitis will have standard investigations to identify the germ causing the infection. In addition the investigators will capture germs using CIM, and will compare CIM with the standard test to see which is better. Funding: departmental funding