Visual Signs and Symptoms
A patient may initially complain of blurred or fluctuating vision and difficulty in colour perception. This may be more evident in one eye than in the other. The patient may then complain of empty or dark areas and floating spots or lines in his vision. In severe form of this condition, the patient may eventually suffer from complete loss of vision.
Work up includes a complete history and physical examination. The following tests should be conducted:
Test results indicate the type and degree of severity of diabetic retinopathy and appropriate treatment can be started.
In cases of nonproliferative DR, laser photocoagulation may be used to treat macular edema due to vascular leakage.
In patients with proliferative diabetic retinopathy, panretinal photocoagulation is used to spare the macular area and treat the entire diseased retina.
This procedure may be used in some patients with proliferative diabetic retinopathy.
Blood sugar level control
This is the primary mode of controlling the progression of retinopathy. By bringing blood glucose to normal levels, edema and other such conditions involved in diabetic retinopathy can be lessened.
The longer a person has diabetes, the higher his chances of developing diabetic retinopathy . If a person has been diagnosed early, he would have well defined leakage and good perifoveal perfusion. His vision loss would be mild and exudates would be minimal. In such cases, prognosis is favourable as with the right control and treatment, the progression of the disease may be halted.
Complications include all the factors that may worsen the ischemic state of the eye such as:
As the name indicates, the primary cause of diabetic retinopathy is diabetes. In type I diabetes mellitus, chances of developing this condition is comparatively less. In patients with type II diabetes mellitus, however, incidence of this condition is directly proportional to disease duration.
Other causes include hypertension and hyperlipidemia which may exacerbate preexisting diabetes and increase the risk of developing diabetic retinopathy. Studies reveal that pregnant women that have this condition have a 4-5% chance of progression to a more severe stage.
Diabetes is responsible for approximately 8000 eyes becoming blinded each year, meaning diabetes is responsible for 12% of blindness .
A recent estimate of the prevalence of diabetic retinopathy in the US showed a high prevalence of 28.5% among those with diabetes aged 40 years or older . Clearly the longer a person has diabetes, i.e the older a person is, the more likely he is of developing retinopathy.
Pre-Proliferative Diabetic Retinopathy
Hyperglycaemia induced intramural pericyte death and thickening of basement membrane leads to vascular wall incompetence. These damages change the formation of the blood-retinal barrier and also make the retinal blood vessels more permeable . Smaller vessels may occlude and the weakened walls of the larger vessels may dilate. As a result microaneurysms and macular edema occurs.
Proliferative Diabetic Retinopathy
Retinal ischemia can result in up-regulation of pro-angiogenesis factors such as VEGF and lead to retinal angiogenesis . Retinal neovascularization may be accompanied by the development of a neovascular membrane on the iris surface, presumable secondary to increased levels of VEGF in the aqueous humor . Gradually, scar tissue develops which may cause retinal detachment and/or build up of intraorbital pressure leading to glaucoma and optic nerve damage.
Diabetes mellitus is a metabolic disorder that results in excess glucose in the blood. This excess amount of glucose causes widespread complications.
The most common and potentially most blinding of these complications, however, is diabetic retinopathy (DR) . In this condition, a person retinal vessels suffer ischemia and damage due to high blood glucose levels resulting in visual loss and in the worst case - blindness.
Diabetic retinopathy is a complication of long standing, and often uncontrolled, diabetes mellitus. It is caused due to raised glucose levels in the blood which damage the blood vessels of the eyes, leading to first blurred vision and finally blindness.
If you are diabetic and feel that your visual power has decreased, you should schedule a consultation with an eye specialist immediately.