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Implementation of Corneal Confocal Microscopy in Primary Care Optometry Practices for Screening and Early Assessment of Diabetic Neuropathy

What did we do?

We assessed the feasibility and acceptability of implementing CCM in community optometry practices alongside routine diabetic eye (retinopathy) screening programme appointments. CCM is an established quick diagnostic tool (eye test) might be an ideal method to study the cornea to detect diabetic neuropathy early.


Why is it important?

The most common complication in diabetes is damage to the nerves in the limbs, particularly the feet and legs; this is called diabetic neuropathy and is caused by chronic high blood sugar levels and diabetes. Around one in five diabetic patients have diabetic neuropathy and it can lead to numbness, pain, loss of sensation, foot ulceration and, in some cases, amputation. Early identification of neuropathy enables earlier treatment to control progression of this serious and life-limiting condition. CCM is a new eye test which can detect diabetic neuropathy in limbs in its earliest stages.


How did we do it?

We evaluated the practical ability of optometrists to capture adequate images using CCM and the time it takes to perform the test, taking into account patient and practitioner perceptions of CCM and the type of training and support that optometrists require to capture images of sufficient quality for analysis. We also produced a budget impact analysis to show the likely impact that routine screening would have on healthcare budgets.


Who did we work with?

Heidelberg Engineering



Our study explored what patients thought about CCM, and whether it would be feasible for high street optometrists to offer the test. In total, 449 patients took part, and most thought the test was acceptable, with 97% agreeing they would have CCM again. Over the course of the study, the time it took to complete the test reduced as optometrists became more confident and familiar with the technique. The quality of the eye images produced also improved over time, and 96% of the images captured were good enough quality for a diagnosis to be made. However, optometrists found around a third of tests difficult to perform, particularly where patients were unable to keep still or fix their gaze while the test was being performed. A number of ways were suggested by the optometrists in which the CCM equipment and training could be improved to help overcome some of the challenges. To provide the CCM test alongside the current annual diabetic eye screening appointment in optometry practices would cost approximately £20 more per person each year.


Downloadable resources



More information

For more information about this project, please contact Susan Howard (Programme Manager)