Diabetes and Eye Health
What you need to know
India has more people with diabetes than almost any other country in the world, and a significant proportion of them will develop some form of diabetic eye disease over their lifetime. The most dangerous thing about it is that it often causes no symptoms until the damage is severe. This page explains what is happening, when to act, and what can be done.
How high blood sugar damages the retina
The retina is one of the most metabolically active tissues in the body, and its blood supply is extremely sensitive to the changes that sustained high blood sugar causes. Over time, elevated glucose damages the walls of the tiny blood vessels that supply the retina. They become leaky, then they close off. The retina, deprived of oxygen, responds by growing new, fragile blood vessels to but these new vessels bleed easily and cause scarring that can detach the retina.
None of this is painful. None of it affects vision noticeably in the early stages. A patient with background diabetic retinopathy to the early form to may have perfectly normal vision at their optician visit while changes are already visible on examination of the retina. This is why the annual dilated eye check is not optional for a diabetic patient; it is the only way to catch the problem before it becomes a crisis. See the diabetic eye care service page for how we diagnose and treat it.
Leaky retinal blood vessels
Fluid and lipid deposits leak from damaged vessels into the retina, causing swelling of the central vision area (macular oedema).
Blood vessel closure (ischaemia)
Capillaries close off, starving areas of the retina of oxygen and triggering the growth of abnormal new vessels.
New vessel bleeding and scarring
New vessels (neovascularisation) are fragile. They bleed into the vitreous and cause fibrous scarring that can pull the retina off.
Stages of diabetic retinopathy
Diabetic retinopathy does not jump from normal to severe. It moves through stages to and each stage has a different treatment requirement and a different urgency. Catching it early dramatically changes the outcome.
Mild non-proliferative retinopathy
Microaneurysms appear to tiny bulges in the retinal blood vessel walls. Vision is completely normal at this stage. No treatment is required, but this finding should prompt tighter blood sugar and blood pressure control, and a six-monthly recheck. This is the stage at which lifestyle management makes the greatest difference to the trajectory of the disease.
Moderate to severe non-proliferative retinopathy
More blood vessels are damaged. Haemorrhages and exudates (protein deposits from leaking vessels) become visible. If the macula (central vision area) becomes involved through swelling, reading vision can begin to drop. Macular oedema at this stage is treated with intravitreal anti-VEGF injections to a procedure performed at Aadithya Eye Care that has dramatically improved outcomes compared to earlier treatment options.
Proliferative diabetic retinopathy
New, abnormal blood vessels grow on the retinal surface and into the vitreous. These vessels bleed easily, causing sudden vision loss from vitreous haemorrhage. Fibrous tissue forms and can contract to detach the retina. Treatment at this stage typically involves laser photocoagulation, anti-VEGF injections, and sometimes vitreoretinal surgery. Outcomes are good when treatment is early; far more limited when delayed. This is the stage that causes the blindness that could have been prevented.
Diabetes affects more than
just the retina
Retinopathy is the most discussed diabetic eye complication, but it is not the only one. Diabetes accelerates several other eye conditions that compound the risk to vision.
Early-onset cataract
Diabetes causes cataracts to develop at a younger age and progress more quickly. The biochemical changes in the lens induced by sustained high blood sugar accelerate the protein changes that cloud it. Diabetic patients may need cataract surgery a decade earlier than non-diabetic patients of the same age.
Neovascular glaucoma
Advanced proliferative retinopathy can cause new blood vessels to grow on the iris, blocking the drainage of fluid from the eye and causing a dramatic and often painful rise in eye pressure. This form of glaucoma is one of the most difficult to treat and is largely preventable by addressing retinopathy before it reaches this stage.
Diabetic macular oedema
Fluid accumulates in the macula (the central part of the retina responsible for reading and detailed vision), causing blurring of fine vision. This can happen at any stage of retinopathy to even mild. It is the most common cause of vision impairment in diabetic patients and is effectively treated with anti-VEGF injections when caught early.
What diabetic patients in Perambur need to hear
Chennai and the wider Tamil Nadu region have some of the highest rates of diabetes in India. In Perambur and the surrounding areas to Madhavaram, Kolathur, Villivakkam to a significant proportion of patients who come to us for any eye complaint turn out to have undiagnosed or unmonitored diabetic eye changes when we examine the retina.
The conversation I find myself having most often with diabetic patients is this: your general physician is managing your blood sugar, your cardiologist is watching your heart, but no one has been looking at your retina regularly. The eye is sometimes the last organ to receive attention in diabetic care planning, and it is one of the most vulnerable. A dilated fundus examination takes about twenty minutes and can detect changes that would not cause any symptom for another year or two to which is exactly the window within which treatment makes the greatest difference.
Good blood sugar control genuinely helps. A patient who keeps their HbA1c below 7% is significantly less likely to progress to the serious stages of retinopathy than one whose control is poor. But "less likely" does not mean "protected" to which is why even well-controlled diabetic patients need their retinas examined annually. If you have been diabetic for more than five years and have not had a dilated eye check in the past twelve months, please book one now. We see patients from across north Chennai, and this visit genuinely belongs in your annual health calendar alongside your diabetes review.
Aadithya Eye Care, Perambur
Diabetes and eye health to
what patients ask
Medical disclaimer: The information on this page is for general guidance only. Diabetic eye disease varies significantly between individuals. Always consult your ophthalmologist for advice specific to your case. Content reviewed by Dr Vasantha Gowri, MBBS, DO (Ophthalmology), FICO (UK), FRCS (Glasgow), Aadithya Eye Care, Perambur, Chennai.
Learn more about diabetes and your eyes
Diabetic Eye Care
How we screen, diagnose, and treat diabetic retinopathy and macular oedema at Aadithya Eye Care.
Read moreMedical & Surgical Retina
Retinal laser, anti-VEGF injections, and surgical retinal care for complex cases in Perambur.
Read moreGlaucoma Care
Diabetic patients face a higher risk of glaucoma. Find out how we monitor and treat it.
Read moreCataract vs Glaucoma
Two conditions that affect diabetic patients more than the general population to explained.
Read moreEye Checkup Frequency
How often diabetics and high-risk groups should have their eyes examined to and what each check covers.
Read moreBlurred Vision
Blurred vision in a diabetic patient is a warning sign that should never be ignored to causes explained.
Read moreMedical sources
- American Academy of Ophthalmology. Eye health information.
- National Eye Institute, National Institutes of Health. Eye conditions and diseases.
- All India Ophthalmological Society. aios.org.
A diabetic eye check could save your vision. Book one today.
Aadithya Eye Care in Perambur provides complete diabetic retinal screening, including dilated fundus examination, OCT where indicated, and clear reporting back to your general physician. Cashless insurance assistance, arranged through our partner hospital for surgery. Accessible from across north Chennai.