The number of diabetics in Hyderabad stands at 10 lakh. Among these, patients who have uncontrolled diabetes for a duration of more than 5 years are susceptible to the complications of high blood sugar. About 30% of diabetics may develop diabetic retinopathy, especially those who are suffering for 10 years or more. Unfortunately, diabetic retinopathy is detected at later stages when much damage has already occurred for the simple reason that there are very few apparent symptoms seen. In fact, sometimes vision problems lead to the diagnosis of diabetes.
A recent study has shown that, in Hyderabad city, about 70% of the facilities do not have the equipment required for diagnosing and treating diabetic retinopathy which can further add to the delay in timely and appropriate care.
What is diabetic eye disease?
In individuals with diabetes, different parts of the eye may be affected such as the retina, macula, lens and the optic nerve.
Diabetic retinopathy: Long standing poorly controlled diabetes affects the tiny blood vessels throughout the body, including those in the retina causing retinal damage. Since retina is responsible for detection of light and converting it into signals to be sent to the brain via optic nerve, diabetics may have blurred vision. Gradually, blood vessels are blocked and newer vessels may be formed. But these vessels are weak and cannot withstand the pressure causing leak or hemorrhage. In more advanced stages, there is extensive scarring of the retinal surface ultimately leading to loss of vision/ blindness.
Diabetic macular edema (DME): Swelling/ edema occurs in the macula region due to build-up of fluid. The macula is important for the sharp, straight-ahead vision that is used for reading, recognizing faces, and driving. This edema becomes the primary cause for loss of vision among people with diabetic retinopathy
Cataract: Cataract is clouding of the eye lens. Breakdown or clumping of the lens occurs with aging or due to high blood sugars leading to blurred or unclear vision. The chances of developing cataract are 2-5 times higher among adults with diabetes and occurs at an earlier age.
Glaucoma: Optic nerve fiber connecting the eye to the brain may get damaged due to elevated pressure inside the eye. Having diabetes doubles the risk of glaucoma in adults.
Risk factors for Diabetic retinopathy :
- Uncontrolled blood sugar
- Long duration of diabetes
- Age >50 years
- Gestational diabetes/ diabetes during pregnancy
- High blood pressure
- High cholesterol
In early stages there are no specific symptoms of diabetic retinopathy. Usually a blurred vision is treated with use of corrective glasses. Later as the disease progresses, we observe serious disturbance in vision due to appearance of floating spots, bleeding, edema and increased risk of irreversible loss of vision.
Early or timely diagnosis can reduce risk of complete blindness by 95% otherwise the loss is permanent. Several tests are available:
Visual acuity test– This is the basic test involving reading of the eye chart from various distances.
Tonometry– The pressure inside the eye is measured using tonometry
Dilation exam– The pupil of the eye is dilated by placing some drops allowing the Doctor to look for abnormal blood vessels, swelling, growth of scar tissue, etc.
Fluorescein angiography – Here, detailed images of the blood vessels in the eye can be obtained by injecting a dye that creates fluorescence as it circulates through the eye
Optical coherence tomography – This testing helps to obtain cross-sectional images of the retina to show its thickness using light waves
The most effective way to prevent diabetic eye disease is to maintain a steady and near normal blood sugar. If there is concomitant high blood pressure and cholesterol, then monitoring and control of these is also necessary. Also, thorough eye check-ups should be undertaken annually for diabetics along with dilation to detect early signs of retinopathy.