Mini, a diabetic, was 55 years old when she made a trip to the hospital for a routine eye examination despite having normal vision. As part of the screening, the doctors performed a dilated retinal examination. The result took her by surprise as she was diagnosed with proliferative diabetic retinopathy. “She had been advised to undergo laser treatment in 2023 but did not proceed with it. After counselling her and her family, she agreed to undergo the treatment to prevent vision loss,” said Dr Subha Kurien Consultant in Ophthalmology at Apollo Adlux Hospital, Angamaly.
The laser treatment stabilised her vision and since then she has been following-up every three months. At her most recent review, there was no deterioration in her vision.
According to her, diabetic patients should consult an ophthalmologist at least once a year. “The vision will be checked, and a dilated retinal test will be performed. If it is normal, another test is required only next year. If there are changes from mild to moderate to severe, they may need frequent follow-ups or six-month follow-ups. Severe cases like proliferative diabetic retinopathy and diabetic macular edema may lead to vision loss,” she said.
High or fluctuating glucose levels for a long time can damage the blood vessels in the back of the eyes. This damage can begin during prediabetes, when blood glucose is higher than normal but not high enough for you to be diagnosed with diabetes, according to the National Institute of Diabetes and Digestive and Kidney Diseases. About one in three people with diabetes who are older than age 40 already have some signs of diabetic retinopathy. Glucose is crucial in the body’s energy metabolism and it is the primary source of energy for cells. However, glucose levels should be maintained for the body to utilise it.
Problems arise when the body does not produce enough insulin or when insulin does not function properly. Glucose accumulates in the blood, leading to persistently high blood sugar levels.
“When blood sugar levels remain high over a long period of time, it damages tissues and structural proteins throughout the body, affecting other organs. In the eyes, high blood sugar damages the endothelium, the inner lining of the small blood vessels in the retina. These damaged blood vessels can become blocked, reducing the oxygen supply to the retina and leading to the formation of abnormal new blood vessels, a process known as neovascularisation. However, these new blood vessels are fragile and prone to leaking proteins and blood, leading to retinal haemorrhages and vision loss,” said Dr Suresh Kumar, diabetologist at Dr Suresh’s Diabcare India, Kozhikode, adding that as the disease progresses, scar tissue may form and pull on the retina, causing retinal detachment, which can result in severe or permanent vision loss if left untreated.
Dr Subha added that the number of people with eye disease increases with the prevalence of diabetes. “If the patient has been living with the condition for 10 years, the chances are high compared to a five-year case. Uncontrolled diabetes cases lead to speedy progression of retinopathy,” she said, highlighting that people with hypertension, kidney diseases, and high cholesterol are also at risk of progression of retinopathy and other diabetes-related eye diseases.
Dr Jothydev Kesavadev, a research diabetologist based in Kerala, said that the biggest mistake people make is that they go only by their glucose levels. “They are always concerned only about the cost and number of medications, and more than 95% of them never check their eyes, kidneys, or liver. Another biggest mistake is that people who have suffered a heart attack, stroke or kidney disease consider only those complications serious and ignore the doctor’s advice to have a retinal check-up. By the time they realise that their eyes are also affected, it could be very late,” he said, adding that a survey in India has shown that not even 40% of people undergoing treatment for diabetes have had their retina checked.
A healthy lifestyle should be followed from childhood to control and prevent the progression of diabetes-related eye diseases, adds Dr Suresh Kumar. “Most people tend to take care of the body and maintain blood sugar levels only in their 40s and 50s. The impact of an unhealthy lifestyle during childhood will be huge. Sugar is just calories without any additional nutritional values like vitamins, minerals or fibre. So it is best avoided,” he said, adding that a healthy lifestyle and physical activity can delay the onset of diabetes in people, even if there is a family history.