Diabetes care beyond blood sugar: Why eye health belongs in the portfolio conversation

“How is your HbA1c?” “What was your fasting blood glucose this morning?” These are often among the first questions asked when assessing diabetes management. Blood sugar readings play an important role in monitoring the condition, but they do not tell the whole story. Focusing only on these numbers can mean overlooking other aspects of health that diabetes can affect, including vision. After all, blood sugar levels cannot reveal what is happening in one’s eye.

When it comes to long-term health, it is important to approach it like a prudent investor, who does not judge the whole portfolio by a single holding. He considers the spread of assets, identifies hidden risks and reviews it regularly. Long-term health, in that sense, requires the same discipline, because the eyes often get left out during the review on diabetes.

It is necessary to know what diabetes is about and understand its impact on one’s eye health as well. Apart from the talk of sugar, diabetes is a metabolic disorder that, over time, can damage blood vessels and nerves. Years of high glucose levels can cause damage to blood vessels over time, beginning with the smallest ones. The retina, the light-sensitive layer of tissue at the back of the eye, is vulnerable because of its extensive network of tiny blood vessels. This damage, over time, can lead to diabetic retinopathy and diabetic macular edema, a swelling at the centre of the retina that blurs sharp vision. Cataracts, glaucoma and other eye disorders also tend to set in earlier in people with diabetes than in those without the condition.

Diabetic retinopathy, meanwhile, is the leading cause of blindness among working-age adults, the very years when people are building careers and supporting families. It needs to be detected and treated early as it can progress to severe visual impairment or blindness, if left untreated. What makes it challenging is that it is a silent killer of eyesight.

Early retinopathy often causes no symptoms at all. By the time someone notices blurred vision, floaters or distortion, the disease may already be well advanced. This is why waiting for the body to send alarm may prove to be risky. The scale of the problem is also set to grow. According to projections cited by the Management of Diabetic Retinopathy (2025), the number of Indians living with diabetes is expected to reach 125 million by 2045, out of which 16.9% are expected to develop diabetic retinopathy.

Consider a 47-year-old man, recently diagnosed with Type-2 diabetes and high cholesterol. His doctors began, as they often do, with lifestyle and diet. Then he noticed something unsettling, when there were mild changes in his vision that came and went. He believed he was going blind.

While his fear was understandable, how he responds was even more important. For one, fluctuating vision is not necessarily a sign of lasting damage, but it is also a reason to conduct a comprehensive eye examination and have a conversation with his healthcare team, including eye clinician, primary-care doctor and diabetes team. Too often a person leaves the clinic with a plan for the blood sugar but no clear instruction about their eyes. This, in fact, highlights the gap between diagnosis and eye care.

The US Centers for Disease Control and Prevention (CDC) notes that more than 90 per cent of diabetes-related vision loss can be avoided through early detection and treatment. The American Diabetes Association (ADA) recommends that people with diabetes have a comprehensive dilated eye exam at least once a year. This exam, in fact, should be treated as a routine diabetes metric and not an optional add-on. It is as important and serious as HbA1c, blood pressure, kidney tests and foot checks. Given how many people are likely to be affected in the decades ahead, that annual exam is one of the most valuable appointments a person with diabetes can keep.

It is important to help patients understand that prevention of vision loss is not limited to only glucose control. Blood pressure, cholesterol and smoking also carry real risk to healthy vision. There is also a need for coordination between primary-care clinicians, endocrinologists and diabetes teams and eye-care professionals. An eye examination result that never reaches the diabetes team, or a glucose trend that never reaches the eye clinic, is a lost opportunity. Care that is managed in silos will always miss something.

Patients, too, should learn to recognise the signs that demand urgent attention. Sudden blurred vision, new floaters, flashes of light, sudden distortion or a curtain-like shadow across the field of vision calls for instant investigation. While they might not always end up being retinopathy, you should never wait for the next scheduled visit to rule that out.

This World Diabetes Day, anyone living with diabetes, and anyone who cares for someone who does, must pledge to run a quiet assessment. The questions you need to ask yourself are: When did you last do a dilated eye exam? Does the eye clinician know the latest blood pressure and cholesterol readings? Does the diabetes team know what the eye exam found?

If the answer to any of these is ‘I’m not sure’, then that is where you need to begin taking charge of your eye health through diabetes management.

Vision is precious. It is one of our most valuable senses, but for those living with diabetes, it becomes imperative to take extra care to protect it. Eye health deserves a permanent place in the diabetes-care conversation. Making regular eye examinations as routine as monitoring HbA1c levels can make an enormous difference in preserving vision over a lifetime.