Epidemic of diabetic retinopathy

With a global epidemic of diabetes and diabetic retinopathy (DR) looming on the horizon, public health systems need to plan ahead to reduce the impact of DR-related visual loss through more effective screening programmes that harness the latest deep learning and artificial intelligence applications, said Professor Tien Yin Wong PhD, FRANZCO, in his EURETINA Lecture. “It is timely to look at this problem as diabetic retinopathy is a global epidemic of major impact that needs population-wide, international strategies to tackle properly. We need to remember that we are dealing with a systemic disease that requires systemic risk factor control. Evolving ocular management, particularly anti-VEGF, has improved management but is resource intensive. We definitely need more efforts to develop DR screening programmes, perhaps with the use of artificial intelligence (AI)technology,” he said. In a timely reminder of the scale of the problem, Dr Wong, medical director of the Singapore National Eye Centre and Chair of the Singapore Eye Research Institute, said that approximately 400 million people will have diabetes by 2030, with half of those expected to have mild diabetic retinopathy. Developing countries will also be most affected by the ravages of the disease. “We do have increasing global epidemiological data on DR, starting with early studies in Wisconsin and the United States in the 1980s and 1990s, which have been supplemented by more recent data from Europe, Asia and Africa. A meta-analysis of the global data enables more precise estimates of the severity of the problem,” he said. Of the 200 million mild-DR patients in 2030, some 30 million will progress to diabetic macular oedema (DME) and 4 million will encounter visual impairment as a result of the disease, noted Dr Wong. Strategies to prevent visual impairment need to shift from tertiary care to include lifestyle changes at the earliest stage to optimise glycaemic, blood pressure and lipid control in order to prevent development of DR and other diabetes-related complications. While these classic risk factors have been shown to be similar in different ethnic groups and communities, there are real gaps in awareness of the problem, said Dr Wong. “In the United States, some 75 per cent of patients with DR and more than half of patients with DR and DME said they were unaware of the ocular implications of their condition,” said Dr Wong. The importance of a comprehensive approach to managing and treating diabetic patients was underscored by Dr Wong. “It needs to be emphasised that DR is a microvascular complication of a systemic disease, so ocular treatment alone is insufficient and we absolutely need to involve general physicians in the process,” he said. While intensive glycaemic control is essential for patients with type 1 diabetes, resulting in a 75 per cent risk reduction of DR, it seems to be less effective in type 2 patients with an average 20 per cent reduction in their risk, he said. Going forward, more efforts are needed to develop effective DR screening programmes, perhaps with the use of AI and deep learning technology, said Dr Wong. “It is challenging to maintain the costs and running of DR screening programmes for people with diabetes, so it is critical that all stakeholders continue to look for innovative ways of managing and preventing diabetes, and optimise cost-effective screening programmes within the community,” he said. While screening for DR, together with timely referral and treatment, is a universally accepted strategy for blindness prevention, its effectiveness is often hampered by issues related to implementation, availability of human assessors, and long-term financial sustainability, he concluded.