Discerning Alterations in Magnetic Resonance Imaging of the Brain and Ocular Coherence Tomography in Diabetes
Principal Investigator:
Dr Uazman Alam
Approved Research ID:
45184
Approval date:
September 24th 2019
Lay summary
MRI scans of the brain have typically been used to diagnose a number of neurodegenerative conditions and more recently, degeneration of the central nervous system has been shown in diabetes. MR Brain imaging can detect areas of damage (neurodegeneration) in the white matter and alterations in function in areas of the brain. Typical MR Brain imaging cannot be carried out as a population screening method in view of the number of people with diabetes (~4 million in the UK). Also, MRI have limited power to detect or track shrinkage of specific areas of the brain, specifically in the outer layers of the brain (cortex, grey matter) containing nerve cell bodies. Therefore, having easier ways to detect nerve degeneration would help improve the detection of those with neurodegeneration, risk stratify individuals and for the search for better therapies which are currently lack in this field of diabetes. Optical Coherence Tomography (OCT) has been increasingly used as a tool in ophthalmic practice but also in research to detect damage that occurs to the nerve layer in the back of the eye (retina). OCT is analogous to ultrasound expect using light to produce an image of the retina. OCT is a common imaging modality and is easily accessible and is relatively inexpensive, painless and well tolerated. Growing evidence has suggested that OCT findings can mirror diabetic nerve damage in the peripheral nerve. However, there is a lack of studies assessing the association of OCT with damage that occurs in the brain. Thinning of the nerves in the retina relates to cognitive problems in neurodegenerative conditions. We aim to compare changes in nerve layers at the back in people with and without diabetes with changes in MRI Brain imaging and markers of degeneration. OCT scans data will be analysed in relation to MRI brain scans undertaken in the UK Biobank study. In addition, cognitive assessment will also be analysed in relation to both of these imaging techniques. We hypothesise that nerve tissue thinning seen on OCT will mirror overall brain degeneration on MRI scans, with a specific layers of the retina (RNFL) showing degeneration at specific brain regions (whole brain, precentral, postcentral, supramarginal gyri and thalamus). The findings of this study aim to ascertain the potential utility of OCT as an important tool for determining neurodegeneration in diabetes with a view to its use as a biomarker in clinical trials of therapies.