Elevated Blood Sugar in Diabetics Significantly Increases Risk of Eye Diseases

A recent study conducted by researchers at University College London highlights a strong link between high blood glucose levels in individuals with diabetes and the development of serious eye conditions. The study, published in BMJ Open, analyzed data from 5,600 adults aged 52 and over over a 14-year period. Findings revealed that older adults with uncontrolled diabetes—those with elevated blood sugar levels at the start—are three times more likely to develop diabetic eye disease compared to those who maintain blood sugar within a normal range.

Specifically, individuals with blood sugar levels above 6.5% on an HbA1c test, which reflects blood sugar over the previous two months, showed a 31% chance of developing diabetic eye disease within the study timeframe. In comparison, those with well-managed diabetes had only a 9% risk. The study also indicated that poorly controlled diabetes increases the likelihood of other eye conditions, such as glaucoma and macular degeneration.

Participants with undiagnosed diabetes also faced higher risks; they were 38% more likely to develop macular degeneration and 23% more likely to develop diabetic eye disease than those with diagnosed and managed diabetes.

Dr. Stephen Jivraj of UCL emphasized the growing number of older individuals with diabetes in England, noting that diabetes diagnoses have more than doubled among working-age populations since the 2000s. The research underscores the importance of early diagnosis and effective management of blood sugar levels to prevent potential vision loss.

Caitlin Lin, the study’s lead author and a Ph.D. candidate at UCL, emphasized that regular eye examinations and wider diabetes testing are crucial, particularly for older adults. While diabetic eye disease primarily refers to diabetic retinopathy, it can also involve glaucoma, macular degeneration, and cataracts. Some researchers argue that increased eye monitoring may partly explain the association.

The study used data from the English Longitudinal Study of Aging (ELSA), which involves comprehensive health questionnaires every two years. The researchers adjusted for variables such as age, smoking, and physical activity, to accurately assess the risk. They found that while the risk for diabetic eye disease increased notably among those with poor glycemic control, there was no significant difference in the development of cataracts among the groups.

Limitations of the study include a decrease in survey participation over time, which could influence risk estimates. Nonetheless, the findings strongly support the need for proper diabetes management and regular eye health checks to reduce the burden of eye disease in the aging population.

Source: https://medicalxpress.com/news/2025-07-high-glucose-people-diabetes-linked.html