Diabetes mellitus is a disease that causes an higher elevation of blood glucose level than normal due to abnormality in the functioning or production of insulin by the pancreas. Diabetes affects smaller blood vessels in our body, especially in the eyes, heart, brain, and kidneys.
The effect of diabetes in the eyes can present as simple redness of eyes, blurring of vision, patchy spots while viewing any object, decrease in vision, or complete loss of vision. These symptoms can be due to infection of the eye, glaucoma, cataract, or diabetic retinopathy.
With changes in lifestyle, such as more sedentary habits and urbanization, diabetes mellitus is on the rise in Nepal, that also, more in the urban communities of the country.
According to the World Health Organization, diabetic retinopathy accounts for 4.8% of the total of 37 million blind in the world. The prevalence of diabetes among urban people aged 20 years and above seems to be 14.6%, and 19% among people aged 40 years and above in urban Nepal. One research found that 50% of diabetic patients on treatment for diabetes were not aware about diabetic retinopathy. Therefore, awareness regarding eye being involved in diabetes mellitus needs to be emphasized, so that visual impairment due to diabetes can be prevented.
The only way to prevent diabetes from affecting the retina is to control blood sugar and increased blood pressure, and recognize and deal with the risk factors. Internal risk factors are age, duration of diabetes, hypertension, serum lipids, nephropathy, and pregnancy. Similarly, external risk factors are uncontrolled diabetes, smoking, alcohol, and contraceptive pills. Ocular risk factors are asteroid hyalosis and cataract surgery, while myopia and posterior vitreous detachment seem to protect the eyes from diabetic retinopathy.
Diabetes can always increase the chance of infection in the body as a whole, as it decreases the immunity of a person. There is always increased risk of having frequent stye, blepharitis, and conjunctivitis in a person with diabetes. People with diabetes are also likely to have increased prevalence of dry eye. If blood sugar is not controlled, minor trauma to cornea can result in corneal ulcer, and healing will be delayed for a longer time than in non diabetic population. Uncontrolled blood sugar level can also cause diabetic cataract even at a younger age.
The most dreaded and visually incapacitating complication is diabetic retinopathy, in which the retina is involved. If timely diagnosis and treatment of diabetic retinopathy is not done, the person can lose sight. Therefore, timely and adequate laser treatment, or intravitreal injection of anti vascular endothelial growth factor, or even surgery can help in saving or restoring vision in patients with diabetic retinopathy.
Some people think that as their blood glucose level is controlled, they will not have complications of diabetes. But, regarding retinopathy, even if the blood glucose is controlled, it is the duration of diabetes mellitus that is the major risk factor for developing diabetic retinopathy. Apart from that, if the kidney is involved due to diabetes, there is more likelihood for the retina to be involved. The more the risk factors, more is the chances of the eye being involved due to diabetes mellitus.
Most of the time, early changes in eyes due to diabetes have no symptoms. Even then, a person with diabetes needs to be screened for diabetic retinopathy at least once a year. Taking a balanced and low-calorie diet, stopping smoking and heavy drinking, and enough physical exercise can help in diabetic control.
Hypertension
According to the WHO, when blood pressure is increased above normal (≥ 140 mmHg of systolic and ≥90 mmHg of diastolic) it is known as hypertension. Among South Asian countries, Nepal reported the highest proportion of hypertension people, i.e. 33.8 percent. Globally, nearly eight million people lose their lives every year due to high blood pressure. When high blood pressure is not treated or controlled, it increases the risk of heart attack (myocardial infarction) or brain attack (stroke), or can damage the kidneys and eyes. Usually, a person with high blood pressure has no symptoms, but some may have symptoms like headache, shortness of breath, or nose bleed. Increasing age, family history, obesity, lack of exercise, smoking, increased salt intake, alcohol, pregnancy, and diabetes are the other risk factors for hypertension.
In the eyes, uncontrolled blood pressure can cause subconjunctival hemorrhage, vitreous hemorrhage (bleeding within the eyes), central retinal vein occlusion, central retinal artery occlusion, hypertensive retinopathy, and hypertensive maculopathy. If a person is suffering from both hypertension and diabetes, there are chances of having complications of both. The only way to prevent these two diseases is to adopt a healthy lifestyle, including a healthy diet, not smoking, not drinking alcohol, and doing regular physical exercise. But, once you have the disease, you should not hesitate to take medicine. A simple tablet can save your life.