Diabetic Macular Oedema

What is Diabetic Macular Oedema?

Macular oedema refers to the swelling or thickening of the macula, the central part of the retina or the light receptive tissue of the eye. Diabetic macular oedema is a complication of diabetes that occurs when fluid leaks from retinal blood vessels and accumulates in the macula of the eye.

The macula is responsible for sharp central vision required to read, drive, sew or recognise a face.

What are the Symptoms of Diabetic Macular Oedema?

During the initial stages of diabetic macular oedema, you may not experience any symptoms. Typical symptoms of diabetic macular oedema are blurred or double vision, sudden increase in eye floaters and abnormal or diminished colour perception.

What are the Risk Factors of Diabetic Macular Oedema?

The risk of developing diabetic macular oedema increases with the following:

Poor blood sugar management over a long period of time
High blood pressure
Kidney disease
Sleep apnoea
High cholesterol
Pregnancy

How is Diabetic Macular Oedema Diagnosed?

To diagnose diabetic macular oedema, your doctor will use eye drops and dilate your pupils to view the retina. A significant test called fluorescein angiography is performed that uses a special dye to illuminate areas of the retina to evaluate the blood vessels. Another diagnostic test is the optical coherence tomography (OCT) which uses a laser camera to capture pictures of the retina, measure its thickness and detect swelling and fluid accumulation. Fundus imaging is another test which takes detailed pictures of the retina to look for irregular blood vessels. Getting regular eye check-ups can help detect it early and prevent damage to your vision.

What are the Treatments for Diabetic Macular Oedema?

Various treatment modalities are available and these include:

Injectable Medications, which are of two types.

Anti-VEGF Shots: Anti-VEGF also referred to as anti-vascular endothelial growth factor involves the injection of a specific group of medicines known as anti-VEGF drugs to prevent abnormal blood vessel growth that could further damage the eye. A patient with diabetic macular oedema can have increased amounts of a protein called VEGF-A, which can lead to leakage of small blood vessels in the affected eye. Anti-VEGF shots blocks this protein and has been found to significantly improve the vision of the affected eye.
Steroids: Steroids help improve vision and reduce swelling of the retina. Steroid treatment may be available as single injections or implants that release the medication over time. OZURDEX® implant is a small rod-shaped implant containing the prescription medicine dexamethasone, a corticosteroid, which is injected into the eye (vitreous) in your doctor's office to treat diabetic macular oedema. The vitreous gel present in the eye slowly dissolves the biodegradable implant releasing the medication. OZURDEX blocks the leakage of the blood vessels present in the retina and reduces swelling or inflammation in your affected eye.

Laser Therapy: Laser photocoagulation is the mainstay treatment for diabetic macular oedema. It is the process of sealing leaking blood vessels, by focusing an intense beam of light (laser), to stop the excess accumulation of fluid in the macula. Diabetic macular oedema is characterised by microaneurysms, small protuberances in the blood vessels of the retina. During green laser therapy, a laser beam is targeted on the microaneurysms. Laser photocoagulation technology using the green wavelength of light is used, as it is readily absorbed by haemoglobin, the iron-containing pigment in blood cells. Haemoglobin present in the microaneurysms absorbs the laser light and promotes clotting of the leaking blood vessels, preventing further leakage from the microaneurysms. Green laser therapy also improves the supply of oxygen inside the retina and reduces the formation of new abnormal blood vessels.