In one of my earlier articles I had mentioned that India has the dubious honour of being called as the Diabetic capital of the world. We can sign a relief that we no longer hold this distinction. In recent studies, taking the absolute figures on the incidence and prevalence of diabetes reported in China, it is clear that China will occupy the number one position. Second in the list is Mauritius, which has about 33% incidence of diabetes. In India it is about 15 to 20 % among urban Indians.
In my previous article I discussed about the renal damage
due to prolonged hyperglycaemea (due to uncontrolled diabetes), today I will be talking about how hyperglycaema can cause damages to the eyes.
Of all the senses, the ability to appreciate the beauty around us is one that makes this life complete. We need vision to enjoy the God’s creation, the nature and the world around us. Let us not forego that ability due to our carelessness.
Diabetic disease may include cataract, glaucoma and retinopathy, cataract-clouding of eye lens-irregular control of blood sugar can lead to early development of cataract.
Glaucoma: Increase in fluid pressure inside the eye that leads to optic nerve damage and loss of vision. A diabetic is twice at the risk in developing the glaucoma than a non diabetic.
Retinopathy: The most common eye disease and a leading cause of blindness all over the world are caused by the changes in the blood vessels of the retina.
In long standing diabetics due to poor control of blood sugar, the blood vessels that supply blood to retina may swell and leak fluid and in some people new blood vessels grow on the surface of the retina. The walls of the new blood vessels are brittle and so may break leading to leakage.
The retina is the light sensitive tissue at the back of the eye and a healthy retina is necessary for good vision. Diabetic retinopathy usually affects both eyes. And over a period of time the retinopathy can get worsened and can lead to blindness.
In the early stages the blood vessels supplying blood to retina get blocked progressively and this is called non-proliferative retinopathy. Where there is a near complete block, the retina sends signals for nourishment which triggers the growth of new blood vessels. These newly grown blood vessels have thin fragile walls, may grow on the retina and Vitreous gel may break and leak blood resulting in severe vision loss and blindness.
What a diabetic has to do.
The diabetics either type 1 or type 2 must have a comprehensive dilated eye examination atleast once a year.
The pregnant women with diabetes must also have eye check up during pregnancy
Often there are no symptoms in the early stages of the disease, nor is there pain. Do not wait for the eye symptoms; be sure to have a comprehensive dilated eye examination.
Blurred vision: When the macula, the central part of the retina that provides sharp central vision, is damaged when new blood vessel grows on the surface of the retina they can bleed into the eye and block the vision.
People with proliferative retinopathy can reduce the risk of blindness by 95% with timely treatment and appropriate follow up.
Some useful tips about symptoms:
If a diabetic sees few specks of blood or spots “floating’ in the vision.
If floating spots occur one has to see the eye doctor immediately.
The eye doctor may do the visual acuity test, dilated eye examination and tonometry. He will check up for the early signs of the disease like leaking blood vessel, retinal oedema (macular oedema) pale fatty deposits on the retina-signs of leak of blood, damaged nerve tissue and any changes to the blood vessels.
If required, the eye doctor may do fluorescein angiogram.
If early stages of retinopathy is detected that is the time for the patient to act to achieve good control of blood sugar, good control of blood pressure and cholesterol.
For macular oedema and proliferative retinopathy the laser treatment is available which will prevent vision loss.
Even if a diabetic achieves good control of blood sugar, blood pressure and cholesterol, it is advisable to have yearly eye check up in order to prevent the vision loss.
Next time we will talk about cardiovascular complications arising due to improper control of diabetes.