Macular oedema

Macular oedema (MO) can occur due to inflammation, retinal vein occlusion, surgery and other reasons. Diabetic Macular Oedema (DMO) is a vision threatening complication of diabetes, to understand more about this specific type of macular oedema visit our Diabetic macular oedema webpage.

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What is macular oedema?

Macular oedema is swelling of the retina at the back of the eye in the macular area usually due to fluid build-up from leakage of damaged or abnormal blood vessels. Macular oedema can occur in common retinal diseases such as wet macular degeneration, diabetic retinopathy, retinal vein occlusion and also in rare conditions such as retinal dystrophies. It can also occur as a result of inflammation following eye surgery, trauma or inflammatory conditions of the retina.

What are the symptoms?

Macular oedema usually causes blurring or distortion of the central vision.  Fine visual tasks such as reading are most noticeably affected by macular oedema. Sometimes there is very little or no blurring when the macular oedema is very mild or if it does not involve the most central part of the macula.

How is it diagnosed?

Macular oedema can be detected or suspected by an optometrist or ophthalmologist by an internal examination of the eye using eye drops to dilate the pupil and a machine called a slit lamp to look at the back of the eye.  It is then confirmed using an OCT scan which can show up the swollen area of the macula at the back of the eye and can also provide a measurement of how abnormally thickened the macula is. Macular oedema can cause the macula to swell up to over 500 microns in thickness.


The treatment of macular oedema depends on the cause and may involve regular but quite painless injections of drugs into the eye. The drug that is used depends on which underlying condition is causing it. 

Macular oedema due to retinal vein occlusion (RVO)

Drugs that have been licensed for macular oedema due to RVO are Lucentis® (medical name ranibizumab), Eylea® (medical name aflibercept) and Ozurdex®.

Macular oedema due to inflammation

Ozurdex has been licensed for treatment of posterior uveitis or severe inflammation at the back of the eye.  Sometimes it is used to treat macular oedema due to inflammation following cataract surgery. Eye drops of steroid may also be used to treat this condition.

Other causes of macular oedema

Macular oedema associated with inherited retinal diseases such as retinitis pigmentosa or optic disc pit can be treated with Dorzolamide eye drops such as Trusopt or Acetazolamide tablets.

Looking for more information about macular oedema?

Call the Macular Society Helpline on 0300 3030 111 or email

Last review date: 04 2022
Next review date: 12 2023

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