What is diabetic macular oedema?
Diabetic macular oedema, often shortened to DMO, is a complication of diabetes that affects the macula. The macula is the central part of the retina responsible for reading, recognising faces and seeing fine detail.
Diabetes can damage the small blood vessels within the retina. When these vessels become weakened or abnormally permeable, they can leak fluid into the macula, causing it to thicken and swell.
This swelling can blur or distort central vision and make everyday tasks more difficult.
Diabetic macular oedema can develop at different stages of diabetic retinopathy. At The Retina Clinic London, it is assessed using advanced retinal imaging to identify and measure fluid, evaluate the retinal circulation and guide personalised treatment.
What symptoms can it cause?
Diabetic macular oedema may cause:
- Blurred central vision
- Distorted or wavy vision
- Difficulty reading or recognising faces
- Dark, faded or washed-out areas in the vision
- Reduced contrast or difficulty seeing fine detail
- Colours appearing less vivid
- Vision that fluctuates over time
Some patients develop early macular swelling before noticing clear symptoms. Regular diabetic retinal assessment is therefore important, even when vision appears unchanged.
How is diabetic macular oedema diagnosed?
The principal test is optical coherence tomography, known as OCT. This non-invasive scan produces detailed cross-sectional images of the macula and can detect even small amounts of retinal fluid or swelling.
At The Retina Clinic London, assessment may also include:
- High-resolution macular OCT to measure the location and severity of retinal fluid
- Ultra-widefield OCT to assess changes beyond the central macula
- OCT angiography to map retinal blood flow without a dye injection
- Ultra-widefield retinal imaging to document diabetic changes across the central and peripheral retina
- Fluorescein angiography to identify leakage, reduced circulation and abnormal new blood vessels
- Visual acuity and contrast testing to measure the effect on vision
- Review of blood glucose control, blood pressure, cholesterol and other relevant health factors
Artificial-intelligence-assisted analysis may also support the monitoring of retinal fluid over time and help assess the response to treatment.
Together, these investigations show how much swelling is present, identify associated diabetic retinal changes and guide an individual treatment and monitoring plan.
What treatments are available?
Treatment depends on the amount and pattern of swelling, its effect on vision, the stage of diabetic retinopathy and the wider health of the eye.
Treatment may include:
- Anti-VEGF eye injections to reduce retinal leakage and macular swelling
- Steroid injections or slow-release implants in selected cases
- Retinal laser treatment where appropriate
- Careful monitoring when changes are mild and stable
- Vitrectomy surgery where traction, persistent bleeding or another surgical complication is present
- Management of systemic risk factors with the patient’s diabetes team, GP or physician
Anti-VEGF injections
Anti-VEGF medicines block vascular endothelial growth factor, known as VEGF. This is a protein that contributes to blood-vessel leakage and abnormal vessel activity in diabetic retinal disease.
Anti-VEGF injections are a principal treatment for diabetic macular oedema. Treatment often begins with injections at relatively close intervals to bring the swelling under control.
As the macula responds and becomes more stable, the consultant will aim to extend the interval between treatments as safely as possible. The schedule is personalised using vision testing and OCT imaging, with the aim of maintaining control while reducing treatment frequency where appropriate.
Steroid treatment
Steroid injections or implants can reduce inflammation and retinal swelling. They may be considered where clinically appropriate, including when the response to anti-VEGF treatment is limited or when a longer-acting option may be beneficial.
Steroid treatment requires monitoring because it can increase pressure inside the eye and contribute to cataract development.
Retinal laser treatment
Retinal laser is used selectively.
Focal or macular laser may be appropriate for certain patterns of leakage away from the centre of the macula. Pan-retinal photocoagulation may be required where diabetic macular oedema is accompanied by proliferative diabetic retinopathy or significant areas of poor peripheral retinal circulation.
Vitrectomy surgery
Vitrectomy is not routinely required for uncomplicated diabetic macular oedema.
It may be recommended where the vitreous is pulling on the macula, known as vitreomacular traction, or where advanced diabetic retinopathy has caused persistent vitreous haemorrhage or tractional retinal detachment.
The aim of treatment is to reduce swelling, stabilise the retina and preserve or improve as much useful central vision as possible.
Why does ongoing monitoring matter?
Diabetic macular oedema can improve, recur or change over time.
Regular follow-up allows the consultant to:
- Measure changes in macular fluid and retinal thickness
- Assess whether treatment is working
- Adjust the interval between injections
- Identify new areas of leakage or reduced circulation
- Monitor eye pressure and treatment-related side effects
- Detect progression of diabetic retinopathy
Good communication between the patient, retina specialist, diabetes team, GP and optometrist also supports long-term eye and general health.
Improving blood glucose, blood pressure and cholesterol control can help reduce the risk of further diabetic retinal damage, although eye treatment may still be required.
Our approach
The Retina Clinic London provides consultant-led assessment and treatment for diabetic macular oedema and the wider spectrum of diabetic retinal disease.
Our approach combines high-resolution OCT, ultra-widefield imaging, OCT angiography, ultra-widefield fluorescein angiography and detailed retinal examination to establish the extent and activity of the condition.
Patients receive a personalised treatment and monitoring plan based on their imaging findings, vision, response to previous treatment and wider health.
Where appropriate, treatment may include anti-VEGF injections, steroid therapy, targeted retinal laser or vitreoretinal surgery. We also work with the patient’s GP, diabetes team or physician to ensure that relevant systemic factors remain carefully managed.
Our aim is to provide a precise diagnosis, timely treatment and close follow-up throughout the patient’s care.
The next step
If you have diabetes and have noticed blurred or distorted central vision, or have been told that you may have diabetic macular oedema, specialist retinal assessment can provide clarity and guide the appropriate treatment pathway.
A sudden or marked reduction in vision should be assessed promptly.
To book your consultation, please call us on +44 (0)20 4548 5310 or visit https://www.theretinacliniclondon.com/book-a-consultation/
We’re here to help.