Proliferative Diabetic Retinopathy

What Is Proliferative Diabetic Retinopathy?

Proliferative diabetic retinopathy is a sight-threatening condition caused due to diabetes. Unlike non-proliferative diabetic retinopathy, proliferative diabetic retinopathy involves blood vessels. This is an advanced stage of diabetic retinopathy. The patient may not experience symptoms but is at high risk of partial or complete vision loss. In poorly controlled diabetes, the blood vessels supplying the nutrients to the retina gets blocked. This triggers the process of neovascularization.

The new blood vessels so formed are not strong and thin. The new blood vessels bleed leading to filling of fluid in the eye. The formation of these blood vessels may also increase intraocular pressure. Immediate treatment is required to prevent further damage to vision.

What Is The Pathophysiology Of Proliferative Diabetic Retinopathy?

Poorly controlled diabetes results in various complications such as diabetic retinopathy, diabetic neuropathy, and diabetic nephropathy. Diabetic retinopathy is a progressive condition. During diabetic retinopathy, neovascularization occurs. These new vessels bleed and leak the blood in vitreous humor leading to cloudy vision. Because of poor blood circulation, scar tissue is formed in retina. This increases the risk of retinal detachment.

Damage to blood vessels is because of increased oxidative stress generated due to the increased level of glucose and fats. Further, there is a reduced level of Nitric oxide, a vasodilator, because of high glucose levels. This creates excess pressure on blood vessels. This increased blood pressure and damage blood vessels.

What Are The Symptoms Of Proliferative Diabetic Retinopathy?

Proliferative diabetic retinopathy has no symptoms unless significant bleeding results in vision problems. Following are some of the symptoms of Proliferative Diabetic Retinopathy:

• Shadow in vision
• Floating spots in the area of vision
• Missing areas in vision

What Are The Causes Of Proliferative Diabetic Retinopathy?

Poorly controlled diabetes is the major cause of proliferative diabetic retinopathy. Untreated diabetic retinopathy also results in the progression of the condition leading to proliferative diabetic retinopathy. Because of high blood sugar, various processes take place in the eye, especially in retina. These processes are responsible for this condition. These processes include change in retinal blood flow, increased level of protein C-kinase, Sorbitol and aldol reductase pathway, increased oxidative stress, increased level of advanced glycation end products, and altered angiotensin enzyme.

Who Is At Risk For Proliferative Diabetic Retinopathy?

People suffering from type 1 and type 2 diabetes are at increased risk of developing proliferative diabetic retinopathy. Risk further increases with increased duration of diabetes. People who have poorly controlled diabetes are at greater risk for developing proliferative diabetic retinopathy as compared to people whose diabetes is controlled. Well-controlled blood pressure and cholesterol in diabetic patients also reduce the risk of proliferative diabetic retinopathy.

How Proliferative Diabetic Retinopathy Is Diagnosed?

Following are various tests performed to evaluate the health of your eyes and the presence of proliferative diabetic retinopathy:

Eye pressure test: As proliferative diabetic retinopathy increases IOP, an eye pressure test is conducted.

Dilated ocular examination: Pupils are dilated with eye drops to evaluate the back of your eye i.e. retina.

Widefield retinal photography: This test provided a widened view of the retina. The ophthalmologist, through this test, evaluates the severity of diabetic retinopathy.

Optical coherence tomography(OCT): This test is conducted to determine the presence of fluid into the macula. The photographs of your eye would be taken during this test.

Fluorescein angiography: This test is done to identify the leaky blood vessels. A dye is injected into your body and a picture is taken during its passage through the retinal vessels. 

How Proliferative Diabetic Retinopathy Be Prevented?

Proliferative Diabetic Retinopathy is prevented by following the below measures:

• Treating or controlling the progression of non-proliferative diabetic retinopathy.
• Undergoing visual examination frequently if you are diabetic.
• Taking medications of diabetes regularly as prescribed to have well-controlled diabetes.
• Stay away from alcohol and smoking.
• Take a healthy diet.
• Make exercise a part of routine activities.
• Limit intake of sugar, salt, and fat.

What Are The Treatment Options Of Proliferative Diabetic Retinopathy?

Treatment of proliferative diabetic retinopathy is done through various methods performed simultaneously. Apart from the direct treatment method, the patient should also have to control diabetes, cholesterol level, and blood pressure. Following are the methods for treating proliferative diabetic retinopathy:

• Laser Therapy
• Surgery

Laser therapy is required to remove the abnormal blood vessels. However, if the blood vessels bleed and the ocular cavity is filled with fluid, then surgery is required to remove the fluid or blood.

How Laser Therapy For Proliferative Diabetic Retinopathy Is Done?

Laser surgery is performed to remove the abnormal blood vessels. This will prevent further risk of bleeding and the progression of proliferative diabetic retinopathy. It is to be noted that Laser therapy does not improve the vision but reduces the risk of vision damage.

What Are The Side Effects Of Laser Therapy?

Following are the side effects of laser therapy:

• Temporary worsening of vision.
• Risk of visual field loss.
• Ineffective laser therapy.

How Retinal Surgery Treats Proliferative Diabetic Retinopathy?

Blood leaked from the new blood vessels in the vitreous cavity is usually absorbed by the body. However, in case the blood is not absorbed and interferes with the field of vision, surgery is required. Such type of surgery is termed as vitrectomy. Hemorrhage is removed during surgery. Surgery is also done to remove the scar tissue and repairing the retina. Untreated scar tissue increases the risk of retinal detachment.