Automatic Retinal Image Analysis (ARIA) – Technology for digital-Public Health

Global Burden of Diseases – Stroke, Dementia, Diabetes…

According to the report by the Global Burden of Disease 2013, the three disease areas that have the highest percentage contribution (%) of age-standardized disability-adjusted life-years (DALY) are neurological disorders, ischemic heart disease and stroke [1]. The overall stroke burden in terms of the absolute number of individuals affected and the number of people with disability from stroke has increased across the globe in men and women of all ages. Stroke is no longer regarded as a disease of the elderly. It is increasing among young and middle-aged adults, likely because of increased metabolic risk factors such as obesity and diabetes mellitus, especially for individuals between 40-64 years in developing countries. For dementia, a similar problem is also found with more than four times increase in the rate of dementia in the low and middle-income countries compared to the high-income countries in the next 30 years. A substantial economic burden is going to impose on our society; the estimated worldwide cost of dementia was US$818 billion in 2015. By now, the global cost of dementia is probably above US$1 trillion.

Effective Prevention for High-Risk Individuals

What can we do about this problem? The WHO Global Action Plan for the Prevention and Control of Non-communicable Diseases (NCDs) 2013-2020 (resolution WHA66.10) estimated that more than 36 million die annually from NCDs (63% of global deaths), including 14 million people who die relatively young, before the age of 70. More than 90% of these premature deaths from NCDs occur in low- and middle-income countries and could have largely been prevented. Most premature deaths are linked to common risk factors, such as tobacco use, unhealthy diet, physical inactivity and harmful use of alcohol [3]. The key to reversing these NCDs problems is to develop an effective health promotion strategy that could empower high-risk individuals to change their lifestyle, including quitting smoking, adopting a healthy diet, increasing physical activity, and drinking responsibly.

The Role of “Digital Public Health” in Health Promotion and Disease Prevention

The term digital public health was quoted from the Corporate report of Public Health England, “Digital-first public health: Public Health England’s digital strategy” to echo the need to use digital innovation and technology to protect and promote health and reduce inequalities [4]. In the United States, a similar initiative was carried out by Harvard Medical School in Omada’s program [5]. Omada Health is a digital therapeutics firm focused on preventing obesity-related chronic conditions; it is a perfect example of how digital health interventions can be used to mitigate the overwhelming burden of chronic diseases.

ARIA development, such as “ARIA-stroke risk”, use retinal images to estimate and quantify the risk of stroke for health promotion purpose. The study included stroke patients admitted to the neurology ward versus normal individuals as control; the results achieved more than 90% sensitivity and specificity. [6]. Primary prevention targeting at high-risk patients is by far the most effective strategy to reduce the burden of stroke, and this approach may identify individuals starting to show signs of vascular characteristics associated with stroke from the retinal images. In another study, we have shown that “ARIA-eWMH” can be used to estimate white matter hyperintensities (WMH) from magnetic resonance imaging (MRI) on the brain based on community-dwelling elderly without stroke or dementia. Among 180 subjects who have their WMH volume estimated by brain MRI and their age-related WMH grading (0-1 vs 2-3), ARIA-eWMH has a sensitivity and specificity of 93% and 98%, respectively, for estimating the risk of cerebral small vessel disease (SVD) [7]. Individuals with cerebral SVD have a higher risk of cognitive decline, stroke and dementia. However, there is increasing evidence showing that WMH and SVD are more dynamic than we originally thought, WMH may increase or decrease in time due to ageing, lifestyle changes and other risk factors. Early detection and intervention may be more effective than waiting until symptoms occurred. Modification of traditional risk factors and a healthy lifestyle are currently the most important prophylactic and therapeutic approaches for SVD [8].


Selected Peer-reviewed Publications and Awards (Relevant to ARIA technology only)