Diabetic Retinopathy–an Emerging Epidemic
India is deemed the world’s capital of diabetes.
The diabetic population in the country is close to hitting the alarming mark of 69.9 million by 2025 and 80 million by 2030.
A diabetic patient is 25 times more vulnerable to the possibility of becoming blind compared to a healthy individual.
Diabetic retinopathy is often symptomless in the early stages, so screening for diabetic retinopathy in all diabetics is of utmost importance.
What causes Diabetic Retinopathy?
Chronically high blood sugar from diabetes is associated with damage to the tiny blood vessels in the retina, leading to diabetic retinopathy. The retina detects light and converts it to signals sent through the optic nerve to the brain. Diabetic retinopathy can cause blood vessels in the retina to leak fluid or haemorrhage (bleed), distorting vision. In its most advanced stage, new abnormal blood vessels proliferate (increase in number) on the surface of the retina, which can lead to scarring and cell loss in the retina.
Diabetic Retinopathy may progress through Four Stages
Mild non-proliferative retinopathy: Small areas of balloon-like swelling in the retina’s tiny blood vessels, called microaneurysms, occur at this early stage of the disease. These microaneurysms may leak fluid into the retina. Moderate non-proliferative retinopathy: As the disease progresses, blood vessels that nourish the retina may swell and distort. They may also lose their ability to transport blood. Both conditions cause characteristic changes to the appearance of the retina and may contribute to diabetic macular oedema (DME). Severe non-proliferative retinopathy: Many more blood vessels are blocked, depriving blood supply to areas of the retina. These areas secrete growth factors that signal the retina to grow new blood vessels. Proliferative diabetic retinopathy (PDR): At this advanced stage, growth factors secreted by the retina trigger the proliferation of new blood vessels, which grow along the inside surface of the retina and into the vitreous gel, the fluid that fills the eye. The new blood vessels are fragile, which makes them more likely to leak and bleed. Accompanying scar tissue can contract and cause retinal detachment—the pulling away of the retina from underlying tissue, like wallpaper peeling away from a wall. Retinal detachment can lead to permanent vision loss.
Combating Diabetic Retinopathy
Most general ophthalmologists across India lack the necessary equipment to detect diabetic retinopathy in its crucial early stages, when the disease is most sensitive to treatment.
As diabetic retinopathy is often symptomless in the early stages, lots of cases remain undetected. This is also because there are only few tertiary level care centres that have diagnostic tools such as a slit lamp, ultrasound and procedures such as fluorescein angiography.
What is DME?
DME is the build-up of fluid (oedema) in a region of the retina called the macula. The macula is important for the sharp, straight-ahead vision that is used for reading, recognising faces, and driving. DME is the most common cause of vision loss among people with diabetic retinopathy. About half of all people with diabetic retinopathy will develop DME. Although it is more likely to occur as diabetic retinopathy worsens, DME can happen at any stage of the disease.
Who is at risk for Diabetic Retinopathy?
People with all types of diabetes (type 1, type 2, and gestational) are at risk for diabetic retinopathy. Risk increases the longer a person has diabetes. Between 40 and 45 per cent of Americans diagnosed with diabetes have some stage of diabetic retinopathy, although only about half are aware of it. Women who develop or have diabetes during pregnancy may have rapid onset or worsening of diabetic retinopathy.
What are the symptoms of Diabetic Retinopathy and DME?
Diabetic retinopathy typically presents no symptoms during the early stages.
The condition is often at an advanced stage when symptoms become noticeable. On occasion, the only detectable symptom is a sudden and complete loss of vision.
Signs and symptoms of Diabetic Retinopathy may include:
- Blurred vision
- Impairment of colour vision
- Floaters, or transparent and colourless spots and dark strings that float in the patient’s field of vision
- Patches or streaks that block the person’s vision
- Poor night vision
- Sudden and total loss of vision
- Diabetic retinopathy usually affects both eyes. It is important to make sure that the risk of vision loss is minimised.
Decoding Diabetic Retinopathy
- It has the potential to cause severe vision loss and blindness
- It involves changes to retinal blood vessels that can cause them to bleed or leak fluid, distorting vision
- It is the most common cause of vision loss among people with diabetes and a leading cause of blindness among working-age adults
- It can be treated with several therapies, used alone or in combination
- DME is a consequence of diabetic retinopathy that causes swelling in the area of the retina called the macula
- Controlling diabetes-by taking medications as prescribed, staying physically active, and maintaining a healthy diet-can prevent or delay vision loss
- Because diabetic retinopathy often goes unnoticed until vision loss occurs, people with diabetes should get a comprehensive dilated eye exam at least once a year
- Early detection, timely treatment, and appropriate follow-up care of diabetic eye disease can protect against vision loss
How is DME Treated?
DME can be treated with several therapies that may be used alone or in combination.
Anti-VEGF Injection Therapy
Anti-VEGF drugs are injected into the vitreous gel to block a protein called vascular endothelial growth factor (VEGF), which can stimulate abnormal blood vessels to grow and leak fluid. Blocking VEGF can reverse abnormal blood vessel growth and decrease fluid in the retina. Available anti-VEGF drugs include Avastin (bevacizumab), Lucentis (ranibizumab), and Eylea (aflibercept). Lucentis and Eylea are approved by the US Food and Drug Administration (FDA) for treating DME. Avastin was approved by the FDA to treat cancer, but is commonly used to treat eye conditions, including DME.
Most people require monthly anti-VEGF injections for the first six months of treatment. Thereafter, injections are needed less often; typically three to four during the second six months of treatment, about four during the second year of treatment, two in the third year, one in the fourth year, and none in the fifth year. Dilated eye exams may be needed less often as the disease stabilises.
Focal/Grid Macular Laser Surgery
In focal/grid macular laser surgery, a few to hundreds of small laser burns are made to leaking blood vessels in areas of oedema near the centre of the macula. Laser burns for DME slow the leakage of fluid, reducing swelling in the retina. The procedure is usually completed in one session, but some people may need more than one treatment. Focal/grid laser is sometimes applied before anti-VEGF injections, sometimes on the same day or a few days after an anti-VEGF injection, and sometimes only when DME fails to improve adequately after six months of anti-VEGF therapy.
Corticosteroids, either injected or implanted into the eye, may be used alone or in combination with other drugs or laser surgery to treat DME. The Ozurdex (dexamethasone) implant is for short-term use, while the Iluvien (fluocinolone acetonide) implant is longer lasting. Both are biodegradable and release a sustained dose of corticosteroids to suppress DME. Corticosteroid use in the eye increases the risk of cataract and glaucoma. DME patients who use corticosteroids should be monitored for increased pressure in the eye and glaucoma.
Why Kokilaben Hospital
We have a state of the art Ophthalmology Department equipped with the most advanced equipment to treat retinal diseases. We are equipped with a Zeiss Fundus Camera for retinal angiography, 532 Zeiss Green Laser for retinal lasers in OPD and during surgeries, ultrasonography—and most importantly the most advanced Alcon CONSTELLATION® vitrectomy surgery machine which is used for 23 and 25 gauge minimal access retinal surgeries.
Increased VEGF (vascular endothelial growth factor) levels in the vitreous are the major culprits in diabetic retinopathy. Anti-VEGF intravitreal injections have become the most important tool in stabilising and reversing diabetic macular oedema as well as controlling proliferative diabetic retinopathy bleeding.
At our hospital we provide the best Anti-VEGF intravitreal injections like Ranibizumab (Accentrix or Lucentis, Razumab) and Aflibercept (Eylea).