When Shamsul Bahri Othman was diagnosed with diabetes in his early forties, he never imagined how deeply it would affect his sight. Four years after his diagnosis, he began losing vision—first suddenly in one eye, then gradually in the other. What started as blurred vision became a life-changing experience. Once able to drive his children to school and work independently as a mechanic, Shamsul now depends on others for daily tasks.
Diabetes-related retinopathy (DR) is caused by long-term damage to the small blood vessels in the retina. With 853 million people projected to live with diabetes by 2050, more than 250 million could experience some form of retinopathy, and around 45 million may progress to sight-threatening stages such as proliferative retinopathy or diabetic macular oedema.
While DR is preventable, millions remain at risk of vision loss because screening and treatment are not equally accessible. Shamsul was diagnosed with diabetes in 2018 and, four years later, with DR. Before his diagnosis, he had never heard of the condition, and his doctor had not explained that he was at risk of developing it. He only discovered the possibility while searching online for information about diabetes-related complications. Because he had no symptoms at the time, he never imagined it could happen to him.
The development of DR is closely associated with the duration of a person’s diabetes. After 15 to 20 years, almost nine in ten people with type 1 diabetes and around two in three people with type 2 diabetes will develop some degree of the condition. There is not one factor, but many, that cause progression. These include prolonged high blood glucose levels, high blood pressure, pregnancy, ethnicity and genetic predisposition. Encouragingly, DR often progresses slowly, giving healthcare teams time to intervene. As a result, only about one in ten people with the condition go on to develop vision-threatening changes.
Pregnancy adds another layer of complexity when hormonal changes can accelerate the development of retinopathy. At the same time, rapid improvements in glucose control, often made to protect the foetus, can sometimes worsen existing eye disease. Preconception care, which allows women with diabetes to optimise glucose levels before pregnancy, is therefore essential in preventing progression during pregnancy.
After 15 to 20 years, almost nine in ten people with type 1 diabetes and around two in three people with type 2 diabetes will develop some degree of the condition
In many cases, early signs of diabetes-related vision damage manifest before other complications. They can indicate complications in the kidneys or heart. Protecting vision, therefore, presents a broader opportunity to intervene early and reduce the risk of more severe systemic complications. In fact, the real culprit is the condition’s painless, asymptomatic progression, which makes early detection difficult without screening.
Treatment options such as laser therapy, anti-VEGF injections, and vitrectomy can slow or stop vision loss when detected early. However, these treatments cannot restore vision once it is lost, making timely screening essential for preserving vision and overall health. Treatment for Shamsul’s right eye involved laser therapy and intravitreal injections. He also underwent a vitrectomy and laser procedure with silicone oil injections in his left eye. Six months later, the silicone oil was removed, and a cataract extraction with a lens implant was performed. Shamsul continues to attend regular follow-up appointments and receives additional injections in his right eye when needed.
Data from the IDF Diabetes Atlas indicate striking regional variations in the prevalence of diabetes-related retinopathy, particularly in parts of Europe and Southeast Asia, where disparities in access to prevention and care are evident. However, it is best to err on the side of caution when interpreting these figures since estimates often depend on the populations studied and the methods used for disease detection. Hospital-based research tends to show higher levels of DR because it captures individuals who are already experiencing symptoms. In contrast, community-based screening tends to provide a more accurate picture of the population.
Studies using handheld or smartphone-based cameras in rural areas make screening possible where hospital infrastructure is limited. Still, image quality and field of view can be lower than in clinical settings with some studies excluding ungradable images, which can further skew prevalence estimates. Ethnicity adds another important dimension: people of South Asian and Black descent are more likely to develop diabetes and its complications, underlining the need for localised strategies that consider entire population characteristics and resources. The differences between regions are not only the result of biology or technology but also of policy and investment.
When countries prioritise regular screening and timely treatment, diabetes-related vision loss declines. One such example is the National Diabetic Eye Screening Programme in the UK. Following its introduction in the early 2000s, diabetes-related vision loss fell by half within just five years. The screening is carried out by trained photographers and graders rather than ophthalmologists, allowing specialists to focus on people who need advanced care. Clinics operate in hospitals, primary care practices, community centres and mobile vans, to screen people wherever they live.
Outcomes from the UK model demonstrate that investment in prevention saves both sight and money. While systematic screening requires upfront costs in staff training, equipment and coordination, it reduces long-term healthcare expenses associated with vision loss and disability. The approach also underscores that screening is only effective when linked to treatment.
Ethnicity adds another important dimension: people of South Asian and African descent are more likely to develop diabetes and its complications
Identifying people with sight-threatening DR is meaningless if they cannot access laser therapy, anti-VEGF injections or surgical care. Comprehensive eye care requires an integrated system that connects prevention, detection and treatment, supported by affordable access to essential diabetes medicines and glucose monitoring.
Although the IDF Diabetes Atlas reports a slight decrease in the overall prevalence of DR— from 27% in earlier editions to 23% in the 11th edition — this apparent progress masks a more complex picture. The prevalence of proliferative retinopathy, the most severe form, has actually increased fourfold, from 1.4% to 6%. This paradox reflects both improvements in diabetes management and the uneven quality of global data collection. It also serves as a reminder that the overall burden of disease remains immense and that continued investment in prevention, research and equitable care is essential.
The prevalence of proliferative retinopathy, the most severe form, has actually increased fourfold, from 1.4% to 6%
Where national screening programmes are not feasible, technology offers new opportunities. Telemedicine enables retinal images to be taken in community settings and graded by specialists based elsewhere, reducing the need for in-person appointments. Artificial intelligence (AI) tools are increasingly capable of identifying more advanced stages of DR, enabling earlier referrals and lower costs. These approaches are already used in India to expand access in under-resourced areas.
However, success depends on ensuring that AI systems are trained on diverse and representative data. Suppose algorithms are developed primarily using images from young or white European populations. In that case, they may perform less accurately when applied to other ethnicities or age groups. Inclusive design and testing are therefore critical to avoid perpetuating inequities in care.
Beyond eye disease, advances in retinal imaging and AI are opening new eye health frontiers. Researchers are investigating how subtle changes in the retina might signal broader systemic diseases, including cardiovascular disease, kidney disease and dementia. The eye, long regarded as a window to the body, could become a vital tool in detecting and managing a range of conditions associated with diabetes and metabolic health.
While technology and clinical innovation hold promise, the foundation of progress lies in education, training and equitable access. Studies show that nearly half of all people with diabetes worldwide are unaware that their condition can cause blindness, and many cannot afford the treatments required to prevent it. Bridging this gap requires concerted action at multiple levels. People living with diabetes need clear, culturally relevant and language-appropriate information explaining why regular eye examinations are vital.
Beyond eye disease, advances in retinal imaging and AI are opening new eye health frontiers
Early detection and treatment result from upskilling healthcare professionals, from doctors and nurses to optometrists. International collaboration is at the core of telemedicine initiatives, shared training programmes and efforts to reduce the cost of essential drugs and equipment. These initiatives support access to affordable screening in low-income countries. Yet even in a high-income region like Europe, universal screening remains far from reality, with fewer than one in five countries offering national coverage for diabetes-related eye disease screening.
For Shamsul, the emotional toll of his diagnosis was overwhelming. He experienced fear of blindness, anxiety about supporting his family, and frustration at the lack of psychological and medical support before symptoms appeared. His story reflects the reality for many people living with diabetes who remain unaware of their risk until vision loss disrupts their lives. It also underlines the importance of awareness, early detection, and access to affordable treatment and support.
Diabetes-related vision loss is not inevitable. We know that early detection and timely treatment not only preserve sight but also save health systems money by reducing the long-term social and economic costs of blindness. With equitable policies, well-trained health professionals, and informed communities, millions of cases could be prevented. Protecting eyesight means protecting independence, livelihoods and quality of life. It also offers a broader lesson: when health systems invest in prevention, they strengthen their ability to manage the many challenges of diabetes. The path forward lies in ensuring that where a person lives no longer determines whether they lose their sight to a preventable complication.
In this episode, host Phyllisa Deroze is joined by Dr Rebecca Thomas to explore the latest findings on diabetes-related eye conditions from the 11th edition of the IDF Diabetes Atlas, which indicate that nearly 1 in 3 people with diabetes have some form of retinopathy – 1 in 10 of whom develop sight-threatening conditions, such as proliferative retinopathy or macular oedema.
