Retinal vascular changes in small vessel disease using optical coherence tomography angiography

Small vessel disease (SVD) is a major cause of dementia and is thought to result from a faulty vascular system. It causes visible features of disease on brain MRI scans such as white matter hyperintensities. These brain features appear but have also been shown to regress offering hope for therapies. Although brain imaging is the main modality used to assess SVD, the very smallest vessels and capillaries cannot be seen due to a limitation of MRI. The microcirculation at the back of the eye is linked with the brain's circulation and can be imaged with retinal cameras. Studying these vessels will help us to develop insights into the pathophysiology of SVD and dementia.
The current project will focus on investigating the smallest retinal blood vessels with the newest eye camera technology, called optical coherence tomography angiography (OCTA). Work to quantify and understand OCTA metrics is being pioneered by NIH grant holders at the University of Southern California (USC). These methods, which are currently unavailable in Edinburgh, will be applied at the UK Dementia Research Institute (DRI) in Edinburgh. Associations with brain changes in a large cohort of patients presenting with small vessel disease and at risk of cognitive complications will be sought. An ongoing collaboration with USC will be established, focusing of retinal microvascular changes in SVD for the purposes of better understanding dementias.

Main objectives:
1. To learn about OCTA and retinal imaging acquisition methods used at the lab of Amir Kashani, University of Southern California, to implement in Edinburgh as part of our studies of small vessel disease, a major cause of dementia;
2. To learn image analysis techniques as applied to OCTA images, to augment our current plans for understanding the relationship between retinal imaging features and brain MRI features of dementia;
3. To establish and develop new links in the field of retinal imaging between USC and Edinburgh.