Ocular diabetes, multiple ocular manifestations due to metabolic disease, but thankfully every day a little closer to ophthalmic success.
Ocualr diabetes form a major ophthalmic problem in developed countries. It is the leading cause of blindness in the 20-64 year age group. About 25% of diabetics have some form of retinopathy, and 5% have severe disease. Diabetic retinopathy can occur in both juvenile diabetes mellitus (type 1) and adult diabetes mellitus (type 2).
The longer you have had diabetes, the higher your risk of developing diabetic retinopathy (DR).
The severity of DR also depends on many other factors: type of diabetes, patient's age, metabolic control, associated hypertension and/or hypercholesterolaemia.
How does hyperglycaemia affect eye health?
Through complex mechanisms that are still being investigated, retinal blood circulation is impaired in two main ways in diabetes.
- Firstly, blood flow through the retinal capillaries is reduced (capillary ischaemia), resulting in deficient oxygen and nutrient supply to the retina. The retina is one of the highest oxygen-consuming tissues in the body.
- Secondly, the barrier function of these capillaries, which in normal situations keeps the retina relatively isolated from blood, is disrupted. As a result, blood plasma and lipids leak into the layers near the centre of the retina, called the macula (macular oedema).
Retinal capillary ischaemia causes the appearance of neovessels (new vessels that try to deliver the oxygen deficit), which result in two of the most feared complications of diabetic retinopathy: vitreous haemorrhage and tractional retinal detachment. If the ischaemia reaches a certain intensity, the neovessels extend over the anterior surface of the iris, which may increase intraocular pressure (neovascular glaucoma)
Ocular diabetes conditions:
- diabetic retinopathy
- neovascular glaucoma
- corneal epithelial disorders
What warning symptoms may a diabetic patient experience?
Most diabetic patients experience no loss of visual acuity until very advanced stages of the process. Therefore, good vision does not necessarily mean that the condition is not present. In advanced stages of diabetes-related eye conditions, impaired vision may already be irreversible so a patient should never wait until this stage before seeing an ophthalmologist.