Magnitude of the diabetes and diabetic eye diseases in India

Increasing incidence of diabetes mellitus poses a major health problem in the world. There are about 50 million people with diabetes in India. This figure is estimated to rise to 87 million by 2030 based on demographic projections, i.e., the growth of the older population where diabetes is more prevalent. Consequences of diabetes include Diabetic Retinopathy(DR) which is a major cause of avoidable blindness worldwide. Various studies conducted in India find that 12-18% of the diabetic population develops DR.

The contributing factors are

• Hereditary
• Inappropriate diet high intake of fat carbohydrates
• Sedentary lifestyle
• Obesity

Diabetes may affect both the young (type 1) and the old (type 2). The latter type is far more common. Regardless of the type of diabetes, many diabetics develop an ocular complication called diabetics retinopathy: a change in the retinal blood vessels that leads to loss of vision.

Normal Vision

Blurred images when seen through affected eyes

Diabetic Retinopathy: A silent presence

The most common eye complication in diabetes is diabetic retinopathy; the other complication are cataract and glaucoma. Early detection and timely diabetic eye treatment will significantly reduce the risk of vision loss. Diabetic retinopathy produces visual symptoms only when it is very advanced. Since only an ophthalmologist can detect early signs of the diabetic retinopathy, all diabetics should have their eyes examined at least once a year.

How does diabetes affect the eye?

Diabetes produces weakening of the blood vessels in the body. The tiny delicate retinal blood vessels are particularly susceptible. This deterioration of the retinal blood vessels, accompanied by structural changes in the retina is termed diabetic retinopathy which leads to loss of vision. Initially the disease is symptomless. Patients will have no complaints and they will have perfect vision. But at the same time bleeding or swelling of retina will be taking place. It is treatable only on examination by the ophthalmologists. That is why it is important to have the retina examined regularly even if your vision is normal.

There are two main causes of vision loss in diabetic retinopathy

Diabetic Muscular Edema:

Weakened blood vessels leak and accumulate fluid in the retina causing swelling and exudation in the macula of retina resulting in moderate vision loss.

PDR (Proliferative Diabetic Retinopathy):

When new abnormal blood vessels grow or proliferate, bleeding into vitreous may occur with sudden severe vision loss.

Eye examination in Diabetic Retinopathy:

Every diabetic is at risk of developing diabetic retinopathy. Sometimes this can happen even if the blood sugar is kept under good control. There are no symptoms at the initial stages. Periodic eye examination with dilated pupils is the only way to detect diabetic retinopathy in early stage and prevent further deterioration of vision.

Diagnosis:

Diagnostic tool such as a slit lamp, ultra sound sonography OCT and produces like fluorescein angiography are used in addition to an ophthalmoscope, to assess the level of diabetic retinopathy.

Flourescein Angiography:

This is a magnified photography of the retina using an injectable dye. It helps to stage diabetic retinopathy, record changes in the retinal blood vessels, and to decide on the need and mode of treatment and evaluate of the treatment.

Treatment:

Lasers are widely used in treating diabetic retinopathy. It is an intense and highly energetic beam of the light that can stop or slow down the progression of diabetic retinopathy and improve or stabilise vision.

The Laser (Argon laser):

Laser treatment is usually performed as an out-patient procedure. The patient is given topical anaesthesia to prevent any discomfort and is then positioned before a slit lamp. The ophthalmologist guides the laser beam precisely on the areas to be treated, with the aid of the slit lamp and a special contact lens. Absorption by the diseased tissue either reduces the retinal thickening or stop bleeding. Additional treatment may be required depending on the patient’s condition. Side Effects: Some patients may experience side effects after laser treatment. These are usually temporary. Possible side effects include watering eyes, mild headaches, double vision, glare or blurred vision. In case sudden pain or vision loss, the ophthalmologist must be contacted immediately.

Anti-VEGF and Injection Steroids:

Recently several types of Anti-VEGF injection and steroids are available to reduce the bleeding and edema and it sometimes improves vision and arrests the progression of disease.

Vitrectomy:

In some patients, there may be bleeding into the vitreous, or the vitreous may pull on the retina and reduce vision severely. These are signs of advanced disease for which a surgical procedure called vitrectomy may be advised at the diabetes eye care clinic.