Retinal imaging as a source of biomarkers for diagnosis, characterization and prognosis of chronic illness or long-term conditions

Abstract

imaging as a source of biomarkers for diagnosis, characterization and prognosis of chronic illness or long-term conditions. Br J Radiol 2014;87:20130832. REVIEW ARTICLERetinal imaging as a source of biomarkers for diagnosis, characterization and prognosis of chronic illness or long-term conditions 1,2 T J MACGILLIVRAY, MSc ABSTRACTThe black void behind the pupil was optically impenetrable before the invention of the ophthalmoscope by von Helmholtz over 150 years ago. Advances in retinal imaging and image processing, especially over the past decade, have opened a route to another unexplored landscape, the retinal neurovascular architecture and the retinal ganglion pathways linking to the central nervous system beyond. Exploiting these research opportunities requires multidisciplinary teams to explore the interface sitting at the border between ophthalmology, neurology and computing science. It is from the detail and depth of retinal phenotyping that novel metrics and candidate biomarkers are likely to emerge. Confirmation that in vivo retinal neurovascular measures are predictive of microvascular change in the brain and other organs is likely to be a major area of research activity over the next decade. Unlocking this hidden potential within the retina requires integration of structural and functional data sets, that is, multimodal mapping and longitudinal studies spanning the natural history of the disease process. And with further advances in imaging, it is likely that this area of retinal research will remain active and clinically relevant for many years to come. Accordingly, this review looks at state-of-the-art retinal imaging and its application to diagnosis, characterization and prognosis of chronic illness or long-term conditions.Currently about 20 million people in the UK suffer from at least 1 long-term condition (a health problem that cannot be cured but can be controlled by medication or other therapies), and this is set to increase 3-fold over the next decade placing an enormous economic and humanresource strain on the National Health Service.1-3 The retina is unique in the body in allowing easy observation of blood vessels with simple, non-invasive instruments. It is also the only accessible site for studying the central nervous system (CNS) in vivo.4 This makes it a ripe environment for the study of systemic and neurological disease, in a patient-acceptable way. Changes to the retina can occur in some chronic diseases years before other signs become apparent. [5][6][7][8][9] Thus, studying the retina may provide an additional means for clinicians to stratify risk and help identify people who would benefit from early lifestyle changes and preventative therapies, as well as assessing the efficacy of new treatments. In addition, there is some early evidence that certain retinal measures may correlate with disease characterization and also prognosis, which not only provides clinicians with a useful assessment tool but also offers research scientists new avenues to explore in the understanding of the p...

Automatic Detection and Distinction of Retinal Vessel Bifurcations and Crossings in Colour Fundus Photography

“…It is, therefore, of great importance to better understand and be able to manage such conditions. The retina is the only inner organ which can be directly imaged, using a fundus camera, and also serve as a "window" for the diagnosis of systematic diseases such as: cerebral malaria, stroke, dementia and cardiovascular diseases [2]. It is also significant that pathologies often affect veins and arteries differently.…”

Retinal changes in the Tg-SwDI mouse model of Alzheimer’s disease

“…The eye is the only part of the CNS that can be visualized noninvasively (Hill et al, 2014; MacGillivray et al, 2014) and it shares many features with the rest of the brain (MacCormick et al, 2015), making it an ideal candidate for the development of biomarkers to diagnose CNS disorders. Visual assessments, such as optical coherence tomography and electroretinography, have been widely used, for over a decade, to detect several diseases, such as cerebral malaria (MacCormick et al, 2015), stroke (Baker et al, 2008), diabetes mellitus (Cheung et al, 2010), hypertension (Wong and Mitchell, 2007), cardiovascular disease (Liew et al, 2011), schizophrenia (Chu et al, 2012; Silverstein et al, 2015) and Parkinson’s disease (Tian et al, 2011; Lee et al, 2014).…”

Modulation of retinal image vasculature analysis to extend utility and provide secondary value from optical coherence tomography imaging

“…3 (2) identifies the location of the center of the fovea (a single click). This creates a circular approximation to the optic disc outline and also places the standard set of measurement zones used in conventional analysis of fundus camera pictures 18 -zone B is a ring 0.5 to 1 optic disc diameters away from the center, and zone C is the ring extending from the optic disc boundary to 2 optic disc diameters away (Fig.…”

“…1,2 The morphometric properties of the retinal vessels have assisted in the new understandings of stroke pathology 3 as well as in diseases of the central nervous system, such as Alzheimer's disease 4 and cerebral malaria. 5 Vascular Assessment and Measurement Platform for Images of the REtina (VAMPIRE) is a semiautomatic bespoke software platform, developed under an academic collaboration among the University of Edinburgh, University of Dundee, Universita degli Studi Di Palermo, and Universita degli Studi di Verona.…”