Diabetic Retinopthay (Diabetic Eye Disease)
Diabetic retinopathy is the pathological change in the retina due to diabetes mellitus.
Diabetic Retinopathy is Common
Patients with diabetes for more than 5 years, there is up to 30% chance of suffering from diabetic eye disease. With more than 15 years of diabetes, the chance increases to 80%.
Symptoms of Diabetic Retinopathy
Patients with diabetic retinopathy may not have any pain or change in appearance in their eyes, their vision may not even be affected in the initial stages. When symptoms occur, irreversible damages may have already developed, therefore regular examinations are necessary. Diabetes increases the risk of blindness by 25 folds.
Types of Diabetic Retinopathy
This represents early changes in the retina. Clinical signs include dot hemorrhages, retinal exudates, vascular wall beadings. The vision remains unaffected unless the exudation involves the macular region of the retina. At this stage, tight control of diabetes and regular eye examinations are required to avoid function decline.
The retina gradually becomes ischaemic and short of nutrients when more capillaries in the retina are blocked. In order to receive more oxygen and nutrients, the retina reproduce blood vessels on the retina and around the optic nerve head. These new blood vessels are particularly fragile; when they bleed into the vitreous, vision will deteriorate rapidly. In addition, fibrovascular proliferation around these blood vessels may contract and subsequently produce traction on the retina causing retinal detachment. When these vessels involve the anterior chamber of the eye, the patient will present with neovascular glaucoma; such secondary glaucoma has a poor prognosis.
Prevention of blindness due to diabetes
"Prevention is better than cure" applies most appropriately to diabetic eye disease. During the initial stages of background diabetic retinopathy, vision remains normal. Therefore when vision is affected, there may already be irreversible pathology. There are several ways to prevent blindness from diabetic eye disease:
If diabetes and blood pressures are controlled well, the risk of developing diabetic retinopathy is reduced.
For patients under the age of 30, an eye examination should be carried out within 5 years of being diagnosed diabetes and annually thereafter.
For diabetic patients over the age of 30, an eye examination should be carried out promptly and then annually thereafter.
As pregnancy can accelerate the progression of diabetic eye disease, an eye examination must be carried out early during pregnancy in any diabetic patient.
Laser treatment is applicable for diabetic exudative maculopathy and proliferative retinopathy. The aim is to seal off the microvascular leakage and reduce neovacularisation.
Par plana vitrectomy surgery
Where proliferative diabetic retinopathy has been poorly controlled, the fragile new blood vessels may bleed causing a vitreous haemorrhage or lead to retinal detachment. In such cases, vitrectomy surgery becomes necessary. This major surgery carries a success rate between 50 - 80% depending on the condition.
Eye injections with anti-Vascular Endothelial Growth Factor( VEGF) can counted macular edema secondary to diabetes.