This diabetic macular edema is swelling of the macula (the place of sharpest vision on the retina) due to fluid accumulation. It is the most common cause of vision impairment in diabetic retinopathy and can occur at any stage of retinopathy.
Causes and risk factors
Chronic elevated blood sugar levels damage the small blood vessels in the retina. The vessel walls become permeable, fluid leaks out and collects in the macula. Important risk factors are:
- Long duration of diabetes
- Poor long-term blood sugar control (high HbA1c)
- High blood pressure
- Fat metabolism disorders
- Pregnancy if you already have diabetes
Symptoms
Typical complaints are:
- Blurred or distorted vision (straight lines appear wavy)
- Decrease in central visual acuity (e.g. when reading or driving)
- Colors are perceived paler
- In the advanced stage: central visual field defects
Diagnostics
The most important examinations are:
- Optical coherence tomography (OCT) – shows the swelling precisely
- Fluorescein angiography – makes leaky vessels visible
- Fundusoscopy
Therapy and prevention
Treatment is usually carried out by an ophthalmologist:
- Injections of anti-VEGF drugs directly into the eye
- Laser treatment of the retina
- Optimization of blood sugar and blood pressure control
- In severe cases: surgical interventions
Further information:
→ Diabetes mellitus – knowledge and overview
→ Why hyporest
→ Diabetic retinopathy
Sources
- German Diabetes Society (DDG). S3 guideline “Diabetic retinopathy”. As of 2025. Available at: www.deutsche-diabetes-gesellschaft.de/leitlinien.
- American Diabetes Association. Standards of Medical Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1). Available at: diabetesjournals.org.
- Robert Koch Institute (RKI). Federal health reporting – diabetes mellitus in Germany. Berlin 2024.
- International Diabetes Federation (IDF). IDF Diabetes Atlas. 11th edition. Brussels 2025. Available at: diabetesatlas.org.
Important note:
The information in this encyclopedia article is intended solely for general and non-binding information. They do not replace medical advice, diagnosis or therapy. If you have any health questions or complaints, please always consult a doctor or qualified healthcare professional. The content was created with the greatest possible care, but errors cannot be completely ruled out.
Last updated: February 26, 2026
