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The Eyes on Diabetes

In Columns
November 14, 2016

Dr K P Poulose

The Eyes – the organ of sight is a pair of spherical bodies contained in a skull cavity – the orbit – well protected on all sides by bones. Your eyes are the doorway to your heart, you can express emotions, share feelings and even convey moods with just a look. A lot can be concluded from the expressions of your eyes. Thus it is no wonder, the eyes have been the source of inspiration to poets, authors and artists since time immemorial. The eyes are windows todiabetes the world and without your eyes, your other senses would indeed find it difficult to enjoy the wonders of life.
World Diabetes day (WDD) is celebrated around the world on Nov. 14th since 1991, Nov. 14th being the birthday of Frederic Banting, who discovered and extracted Insulin from the animal pancreas in 1921 and was awarded the Nobel Prize in 1922. Each year there is a theme chosen for WDD and in 2016 the theme is ‘Eyes on Diabetes’. WDD is celebrated in 160 countries to propagate awareness about Diabetes Mellitus (DM), its causes and prevention of the devastating complications.
The most common diseases affecting the eye in diabetic patients are cataract (whitening of lens), glaucoma (increased intraocular pressure) and retinopathy. Although DM can increase the prevalence of cataract and glaucoma, the main culprit of retinopathy is DM. DM is the leading cause of blindness. Mainly there are 4 types of Diabetes – 1) insulin dependent diabetes (Type 1), 2) non insulin dependent adult onset diabetes (Type 2 ), 3) gestational diabetes (in pregnancy) and 4) drug induced diabetes. There are 415 million adult Type 2 DM (25-79 yrs.) patients in the world and more than 50 lakhs of Type I DM. More than 5.4 million DM patients die per year
globally. Twenty one million women develop DM during pregnancy per year. Seven hundred billion US dollars are spent for diabetic care per year globally. Twelve percent of the global expenditure o
n health is being spent for diabetic patients. One hundred and ninety three million people do not know that they have diabetes (undiagnosed). Eighty six percent of 78.3 million adults with DM in South East Asia (India, Nepal, Bhutan, Maldives, Sri Lanka, Bangaladesh and Mauritius) are in India. China excels India in the total number of Type 2 diabetic patients (109
million v/s 70 millions) while Europe excels India in the number of Type I DM patients (1.4 million v/s 70,000). .
One third of diabetic patients develop retinopathy in their life time. Eye involvement depends on the duration of diabetes, the control of diabetes and associated co-morbid conditions like hypertension, and dyslipidaemia (high cholesterol). Retinopathy is involvement of the retina, (the inner layer of the eye ball). There are 2 type of retinopathy – 1) Non proliferative retinopathy (mild) and 2) proliferative (serious) retinopathy. The network of blood vessels that supply the retina become damaged (microvascular disease) in Diabetes leading to permanent loss of vision.
The disease can be quite advanced before it causes blindness and hence regular screening of eyes in diabetes patients is mandatory at least once in a year for early diagnosis and treatment. In the famous DCCT trial conducted in the 1980s in 1440 Type I patients in USA, it is proved beyond doubt that proper control of blood sugar could reduce retinopathy in 38% of patients.
In a recent study conducted in our hospital on 750 Type 2 diabetic patients, Retinopathy was present in 14.8% while the reported prevalence of DR (diabetic retinopathy) in India is around 12- 30%. Retinal complications in this study patients were related to duration of diabetes, the status of diabetic control and dyslipidaemia.
There are global as well as country specific guide lines for choosing the appropriate therapies. Early insulin initiation, choosing therapies based on individualized parameters avoiding hypoglycemia, cheaper oral therapy in low resource settings are proven strategies to prevent the extensive rise of cost of treating DM and its complications. Regular screening can pick up complications in the early and asymptomatic stage so that preventive measures can be instituted.
(Dr K P Poulose is the Principal Consultant in Medicine and a Senior Diabetologist in S U T Hospital, Pattom, Trivandrum)