Condition Library
Diabetic Retinopathy
If you have diabetes, this is the condition the annual eye exam exists to find. Persistently elevated blood glucose damages the walls of small blood vessels, and the retina is dense with exactly those vessels.
The critical fact is that it produces no symptom at all through its early and even moderately advanced stages. There is no pain, no blur, no warning. By the time vision changes, the damage is usually significant and sometimes irreversible.
Symptoms
- In early and moderate stages, none at all
- Fluctuating vision as blood glucose changes
- Floaters or dark spots, which may indicate bleeding into the eye
- Blurred or distorted central vision, suggesting macular oedema
- Sudden severe vision loss from a large haemorrhage or retinal detachment
Causes and risk factors
- Duration of diabetes, the strongest single predictor
- Poor blood glucose control
- High blood pressure, which independently accelerates it
- High cholesterol, particularly relevant to macular oedema
- Pregnancy, which can accelerate existing retinopathy
- Smoking, which compounds vascular damage
- Kidney disease
Treatment
- Optimising blood glucose, blood pressure and cholesterol, which is the foundation at every stage
- Anti-VEGF injections for diabetic macular oedema and proliferative disease
- Laser photocoagulation to treat leaking vessels or reduce abnormal vessel growth
- Vitrectomy surgery for persistent bleeding or tractional retinal detachment
- More frequent monitoring once any retinopathy is present
Reducing your risk
- Keep blood glucose as well controlled as your care team advises. This is the strongest protective factor and the evidence is unambiguous.
- Control blood pressure, which independently and substantially reduces retinopathy progression.
- Manage cholesterol, which is particularly relevant to diabetic macular oedema.
- Do not smoke, since it compounds the vascular damage diabetes is already causing.
- Have a documented retinal examination every year without exception, regardless of how well controlled your diabetes is.
- Report sudden floaters, a shower of dark spots, or any sudden vision change immediately rather than waiting for your next appointment.
Common misunderstandings about diabetic retinopathy
- That good control means you can skip the exam. Good control substantially reduces risk and does not eliminate it, and retinopathy develops in well-controlled patients. The exam is not a judgement on your management, it is the only way to see what is actually happening.
- That you would notice it developing. You would not, through the early and even moderately advanced stages. The retina has no pain receptors, and central vision is unaffected until the macula is involved or something bleeds.
- That type 2 diabetes is the milder kind for eyes. Type 2 is frequently present for years before diagnosis, which means retinopathy is sometimes already established at the very first eye exam after diagnosis. That is why screening starts immediately for type 2 rather than after five years as it does for type 1.
- That an eye exam for glasses covers it. A refraction is not a retinal examination. What protects your sight is a dilated or ultra-widefield look at the retina, documented and compared year on year.
What we look for and how we document it
Diabetic retinopathy is staged by what is visible in the retina: microaneurysms, dot and blot haemorrhages, hard exudates, cotton wool spots, venous beading, and in proliferative disease, new abnormal vessels. Each of those means something specific about how far the disease has progressed and how urgently it needs treating.
Ultra-widefield retinal imaging is especially useful in diabetes because it captures the peripheral retina, where changes frequently appear before they reach the centre, and because it creates a permanent record. Year-on-year comparison is how subtle progression is caught, and subtle progression is exactly what you want to catch.
We send a report to your physician or endocrinologist after each exam. Diabetic eye care works considerably better when the people managing your diabetes can see what is happening in your retina.
What you control, and what to report immediately
Blood glucose control is the strongest single factor, and the evidence for it is unambiguous. Blood pressure control is close behind and independently reduces progression. Cholesterol management particularly affects macular oedema. None of that is new advice, and all of it is genuinely effective at protecting your sight rather than being generic health guidance.
One practical note that catches people out: when glucose control improves rapidly, vision can temporarily worsen and retinopathy can briefly appear to progress. This settles. It is not a reason to stop improving control, and it is a reason not to have new glasses made during a period of rapid change.
Report immediately, rather than waiting for your next appointment: sudden floaters or a shower of dark spots, sudden blurring of central vision, or any sudden loss of vision. Those can indicate a bleed or macular oedema, and both are time-sensitive.
When to see an optometrist
Everyone with diabetes needs an annual dilated or Optomap-documented retinal exam, regardless of how well controlled it is. Contact us urgently for sudden floaters, a shower of dark spots, or any sudden vision change.
Related conditions
- GlaucomaGlaucoma is painless and takes peripheral vision first. Around half of people who have it do not know. What to watch for and how it is treated.
- Macular DegenerationAge-related macular degeneration takes central vision. What the early signs are, the difference between dry and wet, and why speed matters.
This page is general educational information, not medical advice or a diagnosis. It is not a substitute for an examination. If you are experiencing sudden vision loss, eye pain or an eye injury, contact us immediately or go to an emergency room.
Diabetic Retinopathy questions
My diabetes is well controlled. Do I still need an annual eye exam?
Yes. Good control substantially reduces risk but does not eliminate it, and retinopathy develops in well-controlled patients. The exam is the only way to see what is actually happening in the retina.
Why does my vision fluctuate with my blood sugar?
The lens inside your eye absorbs fluid when glucose is high, changing its shape and therefore your prescription. This is why we avoid finalising a glasses prescription during a period of poor control. It usually stabilises within weeks of steadier glucose.
Can diabetic retinopathy be reversed?
Early changes can improve with better glucose and blood pressure control. More advanced damage is treated to prevent further loss rather than reversed. This is why detection timing determines the entire prognosis.
Does it affect both eyes?
Usually yes, though often not equally. Both eyes are examined and documented at every visit for exactly that reason.
Book an appointment with a doctor who has time for you
We schedule 2 patients an hour, so your exam is unhurried and your questions get answered. Most patients are seen within a few days.