Thousands of patients each year could have the microorganisms causing eye disease diagnosed more quickly and accurately using novel system being trialled in Liverpool, UK. The success of this trial will enable doctors to implement treatment more quickly than currently available with greater accuracy and potentially better outcomes, thereby reducing the need for more protracted and less effective treatments.
The front of the eye is known as the cornea. The cornea is a thin (half a millimetre) transparent membrane, which focus light on the back of the eye. Damage to this membrane leads to scarring, irregularity and a loss of transparency leading to a loss of vision. The cornea, however, is susceptible to infections and this may lead to a painful loss of vision. The sooner the cause of the infection is established, the sooner the appropriate antimicrobial or antibiotic can be administered thereby limiting the damage. Unfortunately using conventional methods the microorganism causing the infection can only be identified in 40% of cases and usually only after 2 to 3 days, a period during which most of the damage is occurring.
Scientists and eye doctors at St Paul's Eye Unit at The Royal Liverpool University Hospital are investigating a novel technique known as metagenomics, to identify the cause of the eye infection. Metagenomics determines the type of DNA present and is many fold more sensitive and rapid than conventional diagnostic methods. Metagenomics can detect the presence of foreign (non-human) DNA and using reference DNA libraries, is able to directly identify the microorganism.
"As with all treatments, earlier and more precise diagnosis gives a much better prognosis for the patient. It may also reduce the need for more expensive and invasive treatments."
European Society of Cataract and Refractive Surgeons (ESCRS) award
The trial is being in part funded by a grant from the European Society of Cataract and Refractive Surgeons (ESCRS) awarded to Dr. Davide Borroni. This ESCRS grant is one of the most prestigious prizes in Europe for ophthalmology and recognises research excellence.
Entitled “METAgenomics guided treatment of CORneal infections – a blinded interventional randomized clinical trial” (META-COR), the trial will recruit an estimated 160 patients and will involve a team of up to 15 ophthalmologists across several EU locations including sites in United Kingdom, Italy, Latvia, Sweden, Greece, Austria and Spain and the USA. The primary clinical centre will be at St Paul's Eye Unit at The Royal Liverpool University Hospital (Professor Kaye and Mr. Romano and Dr. Somerville) and the laboratories at The Centre for Genomic Research (Professor Hertz-Fowler) at The University of Liverpool and The Centre for Integrative Biology (CIBIO) at University of Trento (Italy) (Professor Nicola Segata).
Dr. Borroni said, “If we can show that this new diagnostic test works, the impact on patient care could be substantial by providing within a few hours precise information on the microorganisms causing the infection. That information will enable doctors to target the microorganisms much more quickly and accurately. As with all treatments, earlier and more precise diagnosis gives a much better prognosis for the patient. It may also reduce the need for more expensive and invasive treatments.”
The trial is expected to last for 2 years and the results of the study will be shared with eye doctors around the world.
About microbial keratitis
- Microbial keratitis remains among the top five causes of blindness worldwide.
- Most cases require hospitalisation and intensive treatment.
- Up to 25% of cases are associated with contact lens wear.
- The incidence of microbial keratitis in the developed world increased due to higher rates of contact lens use.
- In developing countries antimicrobial treatments for microbial keratitis are relatively costly and the visual outcome is almost invariably poor, especially in more advanced stages of the disease.
- Advanced stages of microbial keratitis may require corneal transplantation.