Identifying causes behind microbial keratitis (MK) to enable targeted treatment

Brief Lay background

Microbial keratitis (MK) is an infection of the cornea (the transparent front part of the eye) that may lead to ulcers, scarring and blindness. This in turn causes older people to lose their independence, people of working age to lose employment and can be devasting for families and communities, particularly in low and middle-income countries.

Improving outcomes in MK depends on rapidly identifying the microorganism (bacteria or virus) causing the infection and targeting treatment towards this.

What problem/knowledge gap does it help address

One of the barriers to identifying what causes the infection has been the difficulty in collecting samples from the cornea. Until now, this has depended on the use of a sterile blade to scrape the infected area of the cornea. However, it can be very difficult to pick up enough bacteria on the blade for the laboratory to correctly identify what is causing the infection.

Aim of the project

To better define the pathogenic microorganisms in patients with MK through a better understanding of the cornea in health and disease.

Key procedures/objectives

1. Determine the sensitivity and specificity of the existing sampling method for detecting infection.
2. Analyse and compare the corneal environment of the affected and unaffected eye of patients with microbial keratitis (MK).
3. Compare cornea in patients with MK during infection and resolution and in patients without MK, as well as contact lens wearers and eye drop users.

Potential impact on people with sight loss

This research will significantly benefit MK patients both nationally and internationally. It will increase current understanding of corneal sample results and help facilitate the potential use of next-generation sequencing in routine ophthalmic clinical practice.

Next-generation sequencing produces personalised results in a matter of hours compared to three days for conventional diagnostic culture. This allows the most appropriate antimicrobial therapy to be selected, potentially reducing MK disease duration and the risk of blindness. This is particularly important where it is not possible to monitor patients closely.