Prevalence:
The International Diabetes Federation (IDF)’s Diabetes Atlas reports that India has the highest number of people with diabetes in the world, and hence considered to the “Diabetes Capital of the World”.
Currently, 40.9 million Indians are estimated to be suffering from diabetes. By 2025, this number will rocket to 69.9 million, and potentially 85 million by 2030. In addition, 35 million Indians are at risk for diabetes -impaired glucose tolerance (IGT), which is a pre-diabetic state of dysglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology. IGT may precede type 2 diabetes mellitus by many years. It is considered that nearly 14-22% of the population across India fall in the pre-diabetic condition. These people could get diabetes within a decade.
The onset of diabetes in India could be seen as early as 25 years of age.
Increasing prevalence of diabetes is being seen in rural areas of India. In 1990s, Himachal Pradesh has a prevalence of 0.4%. Kochi has excess of 20% and Chennai at 17%, with rural areas of Tripura had a prevalence of diabetes of 9% in a study.
IDF also estimates that the disease will kill about 1 million Indians annually, more than in any other country.
Diabetes and the Eye:
Diabetes affects the eye in various ways.
- Diabetic retinopathy
- Cataract
- Glaucoma
Cataract requires cataract surgery and implant of an artificial lens (or intraocular lens), while glaucoma refers to increase in pressure of the fluid inside the eye (aqueous) that leads to optic nerve damage and loss of vision. A person with diabetes is nearly twice as likely to get glaucoma as other adults.
Diabetic retinopathy refers to damage to the retina caused by abnormal blood flow related to diabetes mellitus, which can potentially lead to severe loss of vision. In some people with diabetic retinopathy, blood vessels may swell and leak fluid. In other people, abnormal new blood vessels grow on the surface of the retina. The retina is the light-sensitive tissue at the back of the eye. A healthy retina is necessary for good vision.
Diabetic retinopathy usually affects both eyes.
Patients with a diagnosis of diabetes are required to undergo regular eye examination, with a thorough retinal evaluation to rule out the presence of diabetic retinopathy, followed by treatment if signs of it are observed.
If you have diabetic retinopathy, at first you may not notice changes to your vision. But over time, diabetic retinopathy can get worse and cause vision loss.
The four stages of diabetic retinopathy:
Mild Nonproliferative Retinopathy. This is the earliest stage of the disease. The stage is diagnosed by a specialist on the basis of small swollen areas in the blood vessels of the retina, referred to as microaneurysms.
Moderate Nonproliferative Retinopathy. As the disease progresses, some blood vessels that nourish the retina are blocked.
Severe Nonproliferative Retinopathy. More blood vessels are blocked, which leads to less blood flow to significant areas of the retina. This lack of blood flow causes low oxygen levels, which induces the retina to grow new blood vessels for helping with nutrition.
Proliferative Retinopathy. This is the most advanced stage of the disease, with growth of new blood vessels as a significant stage in the disease. The new blood vessels, which are abnormal and very fragile, grow along the surface of the retina and into the vitreous gel that fills the inside of the eye. Being thin, with fragile walls, they tend to bleed, leading to collection of blood in the vitreous cavity. This can lead to severe vision loss, while growth of fibrous tissue can lead to traction on the surface of the retina, causing retinal detachment, which can lead to blindness, if not managed in time.
Remember:
- If you have diabetes get a comprehensive dilated eye exam at least once a year.
- Proliferative retinopathy can develop without symptoms. At this advanced stage, you are at high risk for vision loss.
- Macular edema can develop without symptoms at any of the four stages of diabetic retinopathy. You can develop both proliferative retinopathy and macular edema and still see fine. However, you are at high risk for vision loss. Your eye care professional can tell if you have macular edema or any stage of diabetic retinopathy.
- Whether or not you have symptoms, early detection and timely treatment can prevent vision loss.
- If you have diabetic retinopathy, you may need an eye exam more often.
- People with proliferative retinopathy can reduce their risk of blindness by 95 percent with timely treatment and appropriate follow-up care.
Diabetes Control and Complications Trial (DCCT), a trial that studied the effect of tight control of blood sugar on changes in the eye, concluded that better control of blood sugar levels slows the onset and progression of retinopathy. The people with diabetes who kept their blood sugar levels as close to normal as possible also had much less kidney and nerve disease. Better control also reduces the need for sight-saving laser surgery.
Treatment for Diabetic Retinopathy:
1. Laser treatment
2. Anti-VEG-F treatments
3. Potential treatments:
- Results from on-going research indicated that Diabetic Retinopathy would be amenable to gene therapy. To know more, click here.
