Diabetic retinopathy occurs when high blood sugar levels damage retinal blood vessels, leading to vision impairment or blindness.
Published Oct 10, 2024 | 2:00 PM ⚊ Updated Oct 10, 2024 | 4:19 PM
The second Thursday of October is World Sight Day. This year, the theme is “Children, Love Your Eyes.”
Even as the world is observing Sight Day, there is a growing concern about diabetic retinopathy, where the rising prevalence of diabetes is linked to increasing cases of vision loss.
The South Indian states are no exception. Diabetic retinopathy, a severe complication of diabetes, could lead to irreversible blindness, if not detected and treated early.
“Every practice has seen an increase in the prevalence of diabetic retinopathy among patients. However, you could say that this is based on microscopic data,” Dr E Ravindra Mohan, Director at Gleneagles Eye Centre in Chennai told South First.
“I do encounter diabetic retinopathy in my practice. To say whether it has increased over time — yes, it has certainly increased,” he mentioned the grave situation.
According to a recent Lancet study, the age-standardised prevalence of diabetes in South India is approximately 12 percent, with an additional 14 percent of the population classified as prediabetic. Interestingly, there is little gender difference in these rates. However, state-specific data paints a serious picture:
Dr Mohan added that when patients visit him, “I screen them, and every diabetic patient gets a dilated exam. Based on that, I do notice that the incidence of diabetic retinopathy seems to be rising.”
Diabetic retinopathy occurs when high blood sugar levels damage retinal blood vessels, leading to vision impairment or blindness.
Imagine your eyes like a camera, and the part at the back of your eye, the retina, works like a lens. It helps you see things clearly by capturing the light and turning it into pictures that your brain understands.
Diabetes is a health problem caused by too much sugar in the blood. Over time, this extra sugar can hurt many parts of the body, including the tiny blood vessels in the retina.
Consider these blood vessels as small hoses carrying water to your garden. If the hose gets damaged, water won’t reach the plants, and they might not grow well.
Similarly, when these tiny blood vessels in the retina get damaged by high sugar, they don’t work as well. This can make the retina stop working properly, and over time, lead to blurry vision or even blindness.
It progresses through four stages:
Mild Non-proliferative Retinopathy: The blood vessels in the retina start to get small bulges, like little balloons. This doesn’t cause much trouble at first.
Moderate Non-proliferative Retinopathy: The vessels begin to swell and twist. The retina isn’t getting enough blood and nutrients.
Severe Non-proliferative Retinopathy: The blood vessels get even more blocked, and some areas of the retina don’t get blood at all.
Proliferative Diabetic Retinopathy: New, weak blood vessels try to grow to replace the blocked ones. But they’re fragile, like thin pipes that can easily break and leak. This can cause bleeding inside the eye and lead to vision loss.
The Lancet study said that currently, around 18.5 percent of diabetic patients in India suffer from diabetic retinopathy, with prevalence increasing with the duration of diabetes.
The urban-rural divide is also significant, with urban populations facing diabetes rates exceeding 20 percent, while rural populations report rates closer to 10 percent.
Alarmingly, a longitudinal study highlighted an increase in diabetes prevalence among younger individuals (ages 20-39), rising from 4.5 percent to 7.8 percent over the past decade.
Several lifestyle factors contribute to the rising diabetes burden characterised by a high carbohydrate intake and low fiber consumption, coupled with sedentary lifestyles due to urbanisation.
“The shift in our dietary patterns, with more calorie-dense food, and our increasingly sedentary lifestyles—where many of us work desk jobs and are far less physically active than half a century ago—are key contributors to the rise in diabetes and, by extension, diabetic retinopathy,” Dr Mohan explained.
However, he also pointed out that a lack of exercise and poor diet are major factors but stress has also been linked to the spike.
“Stress not only affects the body through various mechanisms, but it also triggers what’s known as the ‘fight-or-flight’ response, which raises stress hormones and, consequently, blood sugar levels,” he said.
“The stress of modern life, such as long commutes, extended work hours, lack of exercise, and financial pressures, have contributed to the growing incidence and prevalence of diabetes,” he further stated.
Dr Mohan also added that there were certainly demographic differences when it comes to diabetes and its complications, including diabetic retinopathy. For example, type 2 diabetes becomes more prevalent with increasing age, though not in a strictly linear manner.
Diabetic retinopathy and other complications—such as those affecting the brain, heart, kidneys, limbs, and nervous system—are influenced by two major factors:
Duration of diabetes: The longer a person has been diabetic, the higher the risk of complications.
Level of control: Even with long-term diabetes, complications are less likely if blood sugar levels are well-controlled.
Age plays a key role and over time, the likelihood of developing complications like diabetic retinopathy increases, especially with poor sugar control. Gender also appears to be a factor, as many studies show that males tend to be affected more than females.
Lifestyle habits, such as consuming high-calorie, dense diets, frequent snacking, weight gain, and a sedentary lifestyle, also contribute to diabetes and, consequently, to diabetic retinopathy.
Dr Mohan said that the awareness of diabetes and diabetic retinopathy seemed to be on an uptick, particularly among educated populations.
However, it is still not uncommon to find patients from upper-middle-class or even upper-class backgrounds, who have been diabetic for over 20 years, yet have never had an eye check-up. This suggests a combination of both a lack of awareness and some degree of denial.
“A unique challenge in our society is the tendency for ‘doctor shopping’. Since healthcare is relatively affordable, patients often switch between different doctors for diabetes treatment and eye care, resulting in a lack of continuity in their medical records and overall care. This lack of consistency can negatively affect the management of diabetic retinopathy,” Dr Mohan cautioned.
Although there was an abundance of information available—through media, articles, and general awareness campaigns—”but whether the knowledge of society overall has increased with time, it’s somewhat hard to say, there’s not been a linear increase in people’s knowledge even after there’s been an explosion of information available,” he said,
General practitioners, family physicians, and other healthcare providers who manage diabetes play a crucial role in promoting regular eye check-ups, such as dilated pupil retinal exams at least once a year.
However, this is often difficult to enforce, especially when patients switch doctors frequently or fail to maintain proper medical records.
Symptoms of diabetic retinopathy typically only appear once the central part of the retina, known as the macula (the most sensitive part of the retina), is affected.
Alternatively, symptoms may occur when there is extensive retinopathy, leading to the growth of abnormal blood vessels that bleed, causing hemorrhages and a noticeable drop in vision.
“The most effective strategy for managing diabetic retinopathy is regular screening. A dilated pupil fundus examination by an ophthalmologist once a year is essential,” Dr Mohan recommended.
“With modern technology, this can even be done remotely. There are various fundus cameras available that require pupil dilation (called ‘med fundus cameras’) as well as cameras that don’t require dilation (known as ‘non-med fundus cameras’),” he said.
Remote screening is possible, and with the integration of artificial intelligence, patients may not even need to visit their eye doctor physically. Regular screening is far more important than waiting for symptoms to arise.
There are certainly economic and social barriers to managing diabetic retinopathy. While most government hospitals, eye centers, and medical colleges now have retina specialists, at least in major facilities, there is still a shortage of specialists required for treating advanced cases of diabetic retinopathy.
“Simple cases of diabetic retinopathy can often be treated by comprehensive ophthalmologists or general ophthalmologists with some training. However, more advanced cases require a retinal specialist, who is relatively scarce. A report suggests there is only one retina specialist for every 1.26 million people, which is far from sufficient,” Dr Mohan said.
To address the shortage, there is a need for more retina training programmes, increased awareness of diabetic retinopathy among ophthalmologists, and greater availability and accessibility of treatment options like laser therapy and injectable medications. Reducing the cost of these treatments through indigenisation is another critical factor, he added.
(Edited by Majnu Babu).
