Diabetic retinopathy is retinopathy (damage to the retina) caused by complications of diabetes mellitus, which can eventually lead to blindness. It is an ocular manifestation of systemic disease which affects up to 80% of all patients who have diabetes for 10 years or more.

Diabetic retinopathy: A common complication of diabetes affecting the blood vessels in the retina (the thin light-sensitive membrane that covers the back of the eye). If untreated, it may lead to blindness. If diagnosed and treated promptly, blindness is usually preventable.

Diabetic retinopathy is the most common and most serious eye-related complication of diabetes. It is a progressive disease that causes retinal swelling and destroys small blood vessels in the retina, eventually leading to vision problems. In its advanced forms, known as “diabetic macular edema” and “proliferative retinopathy,” it can cause moderate to severe vision loss and blindness.

Over time, the disease progresses to its advanced or proliferative stage, and fragile new blood vessels grow along the retina. However, these fragile vessels can bleed easily, and haemorrhage may leak into the retina and the clear, gel-like vitreous that fills inside of the eye. Unless quickly treated, this can result in spots, floaters, flashes, blurred vision, vision loss, and even temporary blindness. In later phases of the disease, continued abnormal vessel growth and the formation of scar tissue may cause serious problems such as retinal detachment and glaucoma, both of which can cause permanent blindness. Diabetic macular edema, which involves swelling in the retina that transiently or permanently impairs vision, can occur at any stage of diabetic retinopathy. Treatment to prevent or reverse this condition remains a major unmet clinical need.

FAQ's

Symptoms ?

Most of cases in early stages have no symptoms.

The list of signs and symptoms mentioned in various sources for Diabetic Retinopathy includes the symptoms listed below:

• Blurred vision
• Flashes
• Floaters
• Retinal bleeding
• Vision impairment

Symptoms of diabetic retinopathy and its complications may include:

• Blurred or distorted vision or difficulty reading.
• Floaters in your vision.
• Partial or total loss of vision or a shadow or veil across your field of vision.
• Pain in the eye.

Treatment ?

Laser treatment (photocoagulation) is usually very effective at preventing vision loss if it is done before the retina has been severely damaged. Surgical removal of the vitreous gel (vitrectomy) may also help improve vision if the retina has not been severely damaged. Because symptoms may not develop until the disease becomes severe, early detection through regular screening is important. The earlier retinopathy is detected, the easier it is to treat and the more likely vision will be preserved. You may not need treatment for diabetic retinopathy unless it has affected the center (macula) of the retina or, in rare cases, if your side (peripheral) vision has been severely damaged.But you do need to have your vision checked every year.

Treatment for diabetic retinopathy is often very effective in preventing, delaying, or reducing vision loss. But it is not a cure for the disease. People who have been treated for diabetic retinopathy need to be monitored frequently by an eye doctor to check for new changes in their eyes. Many people with diabetic retinopathy need to be treated more than once as the condition gets worse. Also, controlling your blood sugar levels is always important. This is true even if you have been treated for diabetic retinopathy and your eyes are better. In fact, good blood sugar control is especially important in this case so that you can help keep your retinopathy from getting worse

Diabetic Retinopathy Incidence ?

Facts about diabetic retinopathy:
• About 5.3 million people in US have diabetic retinopathy, and the figure in India is much higher.
• Thousands of people lose their sight from diabetes each year.
• Most type 1 diabetics develop retinopathy within 20 years of their diagnosis.
• About 21 percent of patients with type 2 diabetes will have retinopathy at the time of diagnosis.
• Diabetic retinopathy is the most common cause of retinal blindness in those between 25 and 75 years old.

Incidence (annual) of Diabetic Retinopathy: 65,000 diabetics develop proliferative retinopathy, the most sight-threatening stage in the US (Research to Prevent Blindness, NISE, NSF). Incidence Rate: approx 1 in 4,184 or 0.02% or 65,000 people in USA [Source statistic for calcuation: “65,000 diabetics develop proliferative retinopathy, the most sight-threatening stage in the US (Research to Prevent Blindness, NISE, NSF)”.

Digital retinal angiography ?

Fluorescein angiography is an established technique for examining the circulation of the human retina. In particular it enables the progression of diabetic retinopathy to be monitored and provides valuable information on the presence, or otherwise, of vascular lesions such as oedema (leakage) and ischaemia (occlusion of the capillaries). The method outlined below allows such changes to identified. A fluorescein angiogram is obtained by photographing the fluorescence emitted from the vessels of the retina after intravenous injection of 5ml of 10% sodium fluorescein. The retina is illuminated with a flash of blue light (490nm) and the yellow-green fluorescent light (530nm) is captured on photographic film by inserting an appropriate filter in the reflected light”s path.

The fluorescein dye takes around 10 seconds to reach the patient”s retinal circulation after injection into the patient”s arm. Photography commences immediately after the fluorescein appears in the choroidal circulation, at a rate of around one per second for the first 15 to 20 seconds. Further frames are taken less frequently up to around 5 minutes

Role of anti-VEGF ( bevacuzimab and ranizibumab) ?

Anti-VEGF factors have revolutionised the treatment of diabetic retinopathy. They when given intra-vitreally, cause decrease in retinal swelling and also reduce the stimuli for new abnormal vessels to grow. Also repetitions of such injections have caused improved vision in cases with severe edema, however laser photocoagulation needs to be done as definitive treatment.

Bevacizumab and ranizibumab are two common such products which have been used extensively, ranizubimab is smaller molecule with more specificity.

WHAT IS OCT?

OCT or optical coherence tomography has revolutionised the management of retinal problems. They are like living autopsy, giving details of layers of retina and d measurements for retinal thickness. This helps in initial diagnosis, as well as follow up of cases, and is non- invasive technique. Patients of diabetic retinopathy do need OCT to regular intervals with comparision scans to evaluate the effect of treatment and progression of disease.