Hypertensive Retinopathy vs Diabetic Retinopathy: How They Compare

If you live with diabetes or high blood pressure, you may have been told there are changes at the back of your eye. That often leads to the comparison of hypertensive retinopathy vs diabetic retinopathy. The two are discussed together because they damage the same part of the eye in a similar way, which makes them easy to mix up. They behave differently once they take hold, and that difference matters for what happens next. In this blog post, we cover what each condition is, where they overlap, how they differ, and what treatment involves.

Quick Overview

• Both conditions damage the small blood vessels of the retina, but one is driven by high blood glucose and the other by high blood pressure.
• Both are usually silent early on, which is why regular retinal imaging matters for anyone with either condition.
• Early hypertensive retinopathy can improve once blood pressure comes down, while diabetic retinopathy tends to progress in stages.
• Having diabetes and hypertension together adds to the risk and can speed up the damage.

We will start with each condition on its own, because the comparison only makes sense once both are clear.

What Is Diabetic Retinopathy?

Diabetic retinopathy is damage to the retina, the light-sensing layer at the back of the eye, caused by high blood glucose over time. High glucose weakens the tiny blood vessels that supply the retina, and those vessels start to leak fluid.

The eye then tries to repair itself, and that repair causes its own problem. New blood vessels grow to replace the damaged ones. These abnormal blood vessels are fragile. They break easily and can bleed into the eye, which is called a vitreous haemorrhage. The same new vessels can also leak fluid into the macula, the small central part of the retina you use for detail. That leaking causes macular oedema.

Diabetic retinopathy is described in five recognised stages. They run from no retinopathy, through mild, moderate and severe non-proliferative disease, up to proliferative diabetic retinopathy, which is the stage where the new vessels have appeared. Macular oedema is counted separately, because it can turn up at any stage and follow its own path. If scar tissue forms and pulls on the retina, the result can be a tractional retinal detachment.

What Is Hypertensive Retinopathy?

Hypertensive retinopathy is damage to those same retinal blood vessels, caused by high blood pressure rather than high blood sugar.

The problem here is force. When blood pushes against the vessel walls too hard for too long, the walls respond by narrowing and thickening. The first visible sign is retinal arteriole narrowing. The retinal arterioles, which are the small arteries feeding the light-sensing tissue, become constricted. Research into how high blood pressure changes retinal vessels notes that these changes depend on your age, how high the pressure has been, and how long you have had it.

Over years of chronically elevated blood pressure, the walls stiffen further. That stiffening is called hyaline degeneration, and it leaves the vessel walls rigid. This stage is sometimes described as arteriosclerotic hypertensive retinopathy. Grading runs from mild, through moderate retinopathy, to severe.

Stiff arteries create a second problem. Where an artery crosses over a retinal vein, the thickened artery presses down on the vein underneath. That pressure can block the vein. If it happens in a smaller branch, it is a branch retinal vein occlusion. If the main vein is affected, it is a central retinal vein occlusion.

When blood pressure runs very high, more shows up on the retina:

• Retinal haemorrhages. Small bleeds where vessels have leaked.
• Retinal oedema. Fluid collecting in the retinal tissue.
• Retinal ischemia. Patches of the retina no longer getting enough blood.

At the severe end sits malignant hypertensive retinopathy. Here the head of the optic nerve swells. Doctors record this as optic disc swelling or optic disc oedema. It signals that very high blood pressure is affecting the whole body, not only the eye.

Two other structures can be caught up in it. Beneath the retina sits a layer of blood vessels called the choroid, fed by the choroidal arteries and the smaller choroidal arterioles. Damage there is hypertensive choroidopathy, and it can let fluid pool under the retina as a serous retinal detachment. The optic nerve itself can also be affected, which is hypertensive optic neuropathy.

What Do the Two Conditions Have in Common?

Quite a lot, particularly early on. Both are retinal vascular diseases, both start without symptoms, and both cause measurable change before anything is visible on a standard examination.

A study using imaging that finds changes before retinopathy appears looked at patients who had no retinopathy on examination. In those with diabetes, and in those with hypertension, the network of tiny retinal vessels was already thinner than normal. The same paper notes that diabetic retinopathy is the leading cause of vision impairment in working-age adults worldwide. Hypertensive retinopathy is less likely to cause vision loss, but it is more common. It affects upwards of 17% of those with hypertension.

The symptoms overlap too, once either condition is established. Vision becomes blurred, dim or patchy. Straight lines can look bent or wavy. Floaters and flashes may appear, along with halos around lights, poor night vision, and more trouble with glare. Needing brighter light to read, or a new glasses prescription more often than usual, belongs on the same list.

How Do They Differ?

The clearest difference is what happens once the cause is under control. Early hypertensive retinopathy can settle, and sometimes partly reverse, when blood pressure is managed. Diabetic retinopathy is graded in stages precisely because it tends to move through them, and treatment aims to slow or stop that movement rather than undo it.

A few other distinctions are worth knowing:

• The pattern of damage. Diabetic retinopathy tends to produce leakage and eventually abnormal new vessels. Hypertensive retinopathy produces narrowing, wall thickening and vein compression.
• The trigger. Diabetic retinopathy relates to how long you have had diabetes and how well glucose has been controlled. Hypertensive retinopathy relates to how high your blood pressure has run, both the systolic blood pressure and the diastolic blood pressure.
• The speed. Chronic hypertension causes gradual change, but a sudden sharp rise in pressure can damage the retina within days.
• New vessel growth. Proliferative diabetic retinopathy is a well-defined stage. Proliferative hypertensive retinopathy is described but uncommon.

 

 

What Happens When You Have Both?

Diabetes and hypertension often occur together, and the retina registers the combination. High blood glucose, high cholesterol and high blood pressure each raise the risk of eye complications, and each makes those complications more severe.

That has a practical upshot. If you have diabetes, controlling blood pressure is part of protecting your sight rather than a separate task. The reverse holds too: uncontrolled systemic hypertension in someone who already has diabetic retinopathy tends to make the retinopathy worse.

There is a wider point here about what the retina reveals. Retinopathy in either condition has been linked with coronary heart disease, chronic kidney disease and stroke. This is why these retinal findings are treated as information about your general circulation, not just your eyes. Where blood pressure is unusually hard to control, other causes may be looked for. These include renal parenchymal disease, meaning damage to the kidney tissue itself, and obstructive sleep apnoea. Doctors call this secondary hypertension. It is distinct from essential hypertension, the common form with no single identifiable cause.

How Are They Diagnosed?

Both are found by examining the retina, and the two are separated by the pattern of what is seen rather than by how your vision feels.

The examination starts with drops to widen the pupil, then a detailed look at the retina and a photograph of it. Optical coherence tomography adds a cross-sectional scan, which is how retinal edema and macular edema are measured. Fluorescein angiography maps blood flow. A dye is injected into a vein in your arm and photographed as it travels through the eye. This shows where circulation has failed, which is called retinal capillary nonperfusion.

Your blood pressure readings and glucose history are part of the picture too. Several other conditions can look similar on retinal imaging and need to be ruled out first:

• Retinal vein occlusion, or a branch retinal artery occlusion affecting the central retinal artery or one of its branches
• Ocular ischemic syndrome and anterior ischemic optic neuropathy
• Retinal arterial macroaneurysms
• Sickle cell retinopathy and systemic lupus erythematosus

In severe hypertension, there may also be hypertensive encephalopathy. That is why the eye examination forms part of an urgent wider assessment.

How Are They Treated?

Treatment runs on two tracks at the same time. One manages the underlying chronic disease. The other treats the retina where damage has already happened.

For hypertensive retinopathy, lowering blood pressure is the treatment, and it is managed medically rather than through the eye. Mild to moderate retinopathy often settles as the pressure comes down. Severe damage may not fully recover, which is why the retina is monitored while your blood pressure is being brought under control.

For diabetic retinopathy, keeping glucose, blood pressure, and cholesterol close to target slows progression, and eye treatment is added when the retina needs it. Retinal laser reduces leakage from damaged vessels and can make fragile new vessels shrink back. Injections into the eye are used for macular oedema and for proliferative disease. Vitrectomy surgery is used in advanced cases with a persistent vitreous haemorrhage or a tractional retinal detachment.

One point applies to both. Treatment can protect the vision you still have and slow further loss, but it generally cannot bring back vision that has already gone. That is why retinal checks are scheduled rather than left until something changes.

Book a Retinal Assessment at Our Clinic

Early diabetic retinopathy and early hypertensive retinopathy are usually silent, so the timing of your eye checks does more for your sight than any symptom you might notice. Retinal imaging can pick up changes while they are still small. 

Dr Edward Roufail is an ophthalmologist with subspecialty training in retinal disease, and he assesses and treats diabetic retinopathy, macular oedema and retinal vein occlusion. Whether you have been referred, are due for a review, or have noticed a change in your vision, we are glad to help. To arrange a consultation at our eye clinic, please call us on (03) 9071 0180.

Frequently Asked Questions

How often should I have my retina checked if I have both diabetes and high blood pressure?

The usual starting point for anyone with diabetes is a check at diagnosis and then at least every two years. Having hypertension as well normally shortens that gap, and if any retinopathy is already present it shortens again. Your own schedule is set by what your last examination showed.

Will my glasses prescription change because of retinopathy?

It can, and a prescription that keeps shifting is worth mentioning rather than simply updating. High blood glucose changes the shape of the lens inside the eye and blurs vision for a while. New glasses are usually delayed until glucose has settled. Frequent changes can also point to retinal change that needs a look.

Can I still develop retinopathy if my blood pressure and glucose are well controlled?

Yes, though the risk is lower. How long you have had the condition matters on its own, so someone with twenty years of diabetes carries risk even with good numbers. Control reduces the chance and slows progression rather than removing the possibility.

Does treating one condition help the other?

Partly, and this is a useful thing to know. Lowering blood pressure helps both, because it takes mechanical strain off retinal vessels that diabetes has already weakened. Glucose control works on diabetic retinopathy specifically and does not treat hypertensive damage.

Are eye injections and lasers used for both conditions?

Not usually. Injections and retinal lasers are established treatments for diabetic retinopathy and macular oedema, and they may also be used for complications of hypertension such as a vein occlusion. Hypertensive retinopathy on its own is managed by treating the blood pressure rather than the eye.

Should I have my eyes checked if I have high blood pressure but no diabetes?

It is worth raising, especially if your blood pressure has been high for years or has been hard to control. There is no national screening program for hypertensive retinopathy the way there is for diabetes. It tends to be picked up during an examination booked for another reason. Any change in vision should be looked at promptly.

Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.

References

https://www.keepsight.org.au/eye_health_diabetes

https://ijsra.net/sites/default/files/fulltext_pdf/IJSRA-2025-2721.pdf