The visual prognosis strongly depends on the stage of the diabetic retinopathy and, above all, whether it is accompanied by diabetic macular oedema. When the condition is diagnosed early, it can be stabilised with the aid of modern treatments and usually does not affect the patient’s vision. Some people with chronic, treatment-resistant macular oedema may never recover their central vision.
Vitreous haemorrhage. A vitreous haemorrhage is the term used to describe bleeding in the posterior chamber of the eye (the vitreous body). It can develop in cases of proliferative retinopathy if the ‘new’ blood vessels rupture and bleed. If the patient has previously undergone laser treatment and the bleeding is normally mild, you can usually wait for it to resolve. If an insufficient area was treated with laser, other complications could arise (e.g., tractional retinal detachment) and in these cases surgery may be needed before the blood can be cleaned and the laser completed.
Proliferative diabetic retinopathy. This is the most advanced stage of diabetic retinopathy. It primarily occurs when several of the blood vessels in the retina become blocked, resulting in an insufficient blood supply. The retina responds by creating new blood vessels to supply blood to the area where the existing vessels have become blocked. This process is called neovascularisation. However, these new vessels grow abnormally and do not provide adequate blood flow to the retina. These new vessels are often accompanied by scar tissue which can cause the retina to wrinkle or lead to tractional retinal detachment.
Neovascular glaucoma. This is a very severe type of glaucoma which can develop in patients with diabetes. It occurs when ‘new vessels’ grow and spread throughout the eye. It requires treatment with laser surgery, and in some cases, in combination with anti-VEGF intravitreal therapy.
In people with diabetes, high blood sugar levels can damage or totally obstruct the tiny blood vessels found at the back of the eye (retina).
This condition is known as diabetic retinopathy. Occasionally, small bulges (microaneurysms) protruding from the blood vessel walls filter or deposit fluids and blood into the retina. This fluid can produce swelling (oedema) at the centre of the retina (macula). This is a severe and chronic eye complaint known as diabetic macular oedema which can lead to vision loss and blindness.
Macular oedema is the most common form of vision loss in people with diabetes, particularly if it goes untreated. It is a chronic complication and even when treated correctly there is no definitive cure. Treatment plans should be individualised to each patient, but repeated drug injections are often required to control recurrences of the oedema.