Diabetes can damage retinal blood vessels before vision changes. Screening and timely treatment help reduce the risk of sight loss.
Do not wait for screening if vision changes suddenly. Sudden worsening, many new floaters or a dark shadow need urgent eye assessment. For sudden loss of sight or a curtain across your vision, seek emergency eye care immediately. Urgent symptoms; retinal warning signs.
How diabetes affects the retina
Diabetic retinopathy damages small blood vessels in the retina, the light-sensitive tissue at the back of the eye. Early changes may involve leaking or blocked vessels. More advanced, proliferative disease involves fragile new vessels that can bleed or lead to scarring. Diabetic retinopathy.
Diabetic macular edema, often shortened to DME, is swelling caused by fluid leaking into the macula. This central area of the retina provides the detailed vision needed for reading and recognizing faces. DME is one way diabetic eye disease can affect sight. Macular edema.
Symptoms and risk
Early retinopathy often has no symptoms, which is why feeling that you see well does not replace screening. Later changes can include blurred or fluctuating vision, floating spots and difficulty seeing in dim light. Symptoms and screening.
Risk increases with the duration of diabetes. Blood glucose, blood pressure and cholesterol management all matter. Work with your diabetes team on individual targets, and keep the eye checks recommended for your situation. People with pre-existing diabetes should discuss additional eye checks when planning pregnancy or becoming pregnant. Risk and prevention.
What the tests show
Retinal photographs and a dilated examination help detect blood-vessel changes. An OCT scan produces detailed images that show retinal swelling. In some cases, a fluorescein angiogram uses dye and photographs to examine circulation and leakage. Screening identifies people who need further assessment; your eye specialist sets the monitoring or treatment plan. Screening; retinal tests.
Treatment depends on what is affected
Early disease may need monitoring and attention to diabetes-related risks. Treatment for sight-threatening disease may include anti-VEGF injections, selected steroid treatments, retinal laser or surgery to remove blood or scar tissue. The best approach depends on the findings and visual function. Treatment cannot promise to recover all lost sight, and repeat visits are often necessary. Treatment options.
Why might a specialist recommend observation for DME?
The 2019 Protocol V trial studied adults with center-involving DME who still had good vision. At two years, initial observation with injections if vision worsened did not produce significantly more vision loss than immediate injections. Observation involved regular specialist checks and defined rescue treatment. This finding does not apply to everyone with DME and is not a reason to postpone care or miss follow-up. Read Protocol V.
Diabetic Retinopathy and Diabetic Macular Edema illustrated
Questions to ask
- What stage is the retinopathy, and is the macula affected?
- What changes are visible on my photographs or scan?
- What benefit is expected from treatment, and what are the risks?
- When is my next review, and whom should I contact if vision changes?
Frequently asked questions
Can retinopathy exist when I see clearly?
Yes. Screening can find changes before they affect sight. Early disease.
Does better diabetes control replace eye treatment?
No. Managing diabetes helps, but retinal treatment may still be needed. Treatment.
Is every swollen macula caused by diabetes?
No. Other retinal conditions, inflammation and eye surgery can also cause macular edema. Other causes.
Related reading: Diabetic eye care and retinal detachment.
This information is educational and cannot diagnose an eye condition or replace an individual assessment.
Sources and further reading
- National Eye Institute: Diabetic retinopathy
- NHS: Diabetic retinopathy
- National Eye Institute: Macular edema
- DRCR Retina Network Protocol V, JAMA (2019)
- National Eye Institute: Retinal detachment
General educational information prepared October 2026. Treatments described are general options; availability and suitability require an individual assessment.
