Diabetes is the fastest growing chronic condition in Australia. 956,000 Australians have Type 2 diabetes while 120,000 Australians have Type 1 diabetes. One in four people with diabetes have diabetic retinopathy (damage to the retina from diabetes). Elevated blood sugar levels cause damage to the micro-circulation, and the eye is unique as it is the only place in the body it is possible to directly view this damage.
Diabetic retinopathy can be:
1) Non-proliferative– this can be mild, moderate or severe. On clinical examination, areas of bleeding in the retina (intraretinal haemorrhages), microaneurysms or changes in the veins (venous beading) may be seen.
2) Proliferative– in proliferative disease, abnormal fragile new blood vessels form. These can bleed causing sudden visual loss due to bleeding in the jelly of the eye (vitreous haemorrhage), contract and pull off the retina causing visual loss ( tractional retinal detachment) or block the drainage angle in the front of the eye causing the pressure in the eye to rise and subsequently damage the optic nerve (neovascular glaucoma).
Diabetic macular oedema can occur at any stage of diabetic retinopathy. This occurs when diabetes causes swelling at the central part of the eye responsible for fine vision and can cause severe central visual impairment.
Treatment of diabetic eye disease can include:
1) Close monitoring of the retina for progression, optimal control of blood sugars, high blood pressure and high cholesterol.
2) Laser treatment- peripheral laser treatment (pan retinal photocoagulation) is used to treat proliferative diabetic retinopathy. Macular laser can be used to treat diabetic macular oedema.
3) Injections- anti-vascular endothelial growth factor medication may be injected into the eye to treat macular oedema causing visual impairment. Intravitreal steroid implants are also available for patients who have had previous cataract surgery or who are schedule for upcoming cataract surgery.
4) Surgery- Vitrectomy surgery may be necessary in severe disease causing retinal detachment or long standing vitreous haemorrhage.
Diabetes can also cause cataracts to develop at a younger age compared to patients without diabetes. Once again, it is imperative that patients with diabetes maintain good control of their blood sugars to reduce the risk of eye complications.