Good Blood Sugar Control May Lower Risk of Eye Diseases in Older Adults, Study Finds

Using data from the English Longitudinal Study of Ageing (ELSA), the study followed over 5,600 participants aged 50 and above across eight waves of data collection from 2004 to 2019. Researchers analyzed nearly 29,000 observations, using logistic regression models to assess the relationship between baseline blood sugar status and the later development of eye conditions.

Participants were grouped based on their diabetic status and glycated hemoglobin (HbA1c) levels: non-diabetic (HbA1c <6.5%, no diabetes diagnosis), controlled diabetes (diagnosed with diabetes, HbA1c <6.5%), uncontrolled diabetes (diagnosed, HbA1c ≥6.5%), and undiagnosed diabetes (no diagnosis, HbA1c ≥6.5%). Adjustments were made for various factors, including age, gender, physical activity, BMI, and smoking.

The study led to the following findings:

• Well-controlled diabetes was associated with a lower risk of developing glaucoma, diabetic eye disease, and macular degeneration in older adults.
• Individuals with undiagnosed diabetes had a 1.38 times higher risk of developing macular degeneration compared to those with controlled diabetes.
• Those with uncontrolled diabetes were 1.20 times more likely to develop diabetic eye disease than those with controlled diabetes.
• Even individuals without diabetes had a 1.29 times higher risk of glaucoma compared to those managing diabetes effectively.
• There was no significant association between blood sugar control and the risk of developing cataracts.

According to the researchers, “Our findings suggest that maintaining good blood sugar control in older age not only helps in diabetes management but may also play a crucial role in preventing vision-related complications.”

The study is notable for its use of a large, nationally representative cohort with detailed biomarker and lifestyle data, offering valuable insights into the long-term effects of metabolic health on eye disease. However, the authors acknowledged limitations, such as reduced sample size over time due to participant attrition and the use of subjective physical activity data without duration metrics.

Overall, the study supports routine screening for eye diseases in older adults, particularly those with diabetes or elevated blood sugar levels. It also reinforces the need for early detection and proper glycemic control to help reduce the burden of preventable vision loss in aging populations.

Reference:

Lin C, Jivraj SAre diabetes and blood sugar control associated with the diagnosis of eye diseases? An English prospective observational study of glaucoma, diabetic eye disease, macular degeneration and cataract diagnosis trajectories in older ageBMJ Open 2025;15:e091816. doi: 10.1136/bmjopen-2024-091816