Keep an eye on ‘Diabetic eyes’
Diabetic retinopathy continues to be an important cause of vision deterioration. Approximately 1 in 3 people living with diabetes have some degree of diabetic retinopathy and 1 in 10 will develop a vision threatening form of the disease.
The wreckage caused by diabetes in the eyes are many. When it affects the light sensitive layer retina inside the eye it is called diabetic retinopathy. In diabetes the blood flow to the retina can get blocked and can cause retinal ischemia.
The blood vessels in the retina also bulge, leak fluid and fat causing oedema or swelling especially in the area called macula which is the highly sensitive area of the retina and has the highest acuity of vision. The macula is needed for reading, driving, recognising faces and executing other activities that require finer sharper vision.
Diabetic retinopathy is asymptomatic in early stages. We can control and treat it if detected early and vision can be preserved. Hence early detection with periodic dilated fundus examination is absolutely necessary.
Risk factors
Risk factors for developing diabetic retinopathy are duration of diabetes, older age, poor blood sugar control, high blood pressure, high cholesterol level, pregnancy and smoking.
Recommended schedule of eye examination is 5 years after onset of diabetes for Type 1 diabetes mellitus and at the time of diagnosis for Type 2 diabetes. There after annual dilated pupillary examination is a must for all persons with diabetes. In progressing or life threatening diabetes dilated examinations should be repeated more frequently.
There are mainly 2 stages of diabetic retinopathy. Non proliferative and proliferative. Non proliferative diabetic retinopathy affects the background of retina. This can be arrested by proper control of diabetes and surveillance. Progression of diabetic retinopathy over time can cause proliferative diabetic retinopathy in which new blood vessels are formed in the retina which are of no use and instead are prone to bleeding and leakage.
In order to save eyes, following tests are carried out: Dilated fundus examination
Eye drops are administered in the eyes to dilate the pupil and the retina is examined with a magnifying lens to pick up any diabetic changes in the retina.
Colour fundus photography
A special camera is fitted to the microscope and photos of the retina are taken.
Fluorescein angiography
Here a dye is injected to a vein in the arm and photos of the retina are taken once the dye reaches the retina to assess leakage of blood vessels. OCT or optical coherence tomography can scan the different layers of the retina and helps to detect the presence and extent of fluid collection in the macula which helps to treat the affected areas.
Treatment options
In the early stages no treatment is necessary. Proper control of diabetes, blood pressure, cholesterol, diet and proper exercise can arrest the progress of diabetic retinopathy.
Laser treatment High energy laser treatment can seal the leaking blood vessels and also destroy the unhealthy blood vessels causing bleeding Intravitreal injection of anti VEGF is given for fluid collection in the macula and for preventing growth of new blood vessels.
Once vitreous haemorrhage and tractional detachment set in, the only treatment is surgery. The blood and scar tissues are cleaned by vitrectomy surgery and if there is detachment of the retina the retina is reattached by surgery.