A long term complication of diabetes (both type 1 and diabetes type 2) and one of the leading causes of visual impairment or blindness. People with diabetes are subject to multiple visual complications such as cataracts,glaucoma and trachoma. This eye pathology referred to as diabetic retinopathy is caused by changes in small blood vessels in the retina; the area of the eye that receives images and sends information about the images to the brain. It‘s richly supplied with blood vessels of all kinds. There are three stages of retinopathy;
- Non proliferative(background) retinopathy
- Preproliferative retinopathy and
- Proliferative retinopathy.
Nearly all patients with type 1 diabetes and type 2 have some degree of retinopathy after 20 years. An advanced form of background retinopathy and pre proliferative retinopathy is considered a precursor to the more serious proliferative retinopathy. In preproliferative retinopathy there are more widespread vascular changes and loss of nerve fibers a research shows that patients with preproliferative retinopathy are likely to develop proliferative retinopathy within a short time(less than 1 year).
As with background retinopathy, if visual changes occur during the pre proliferative stage they are usually caused by macular edema. Proliferative stage is characterised by proliferation of new blood vessels growing from the retina into the vitreous. These new vessels are prone to bleeding or hemorrhage. The vitreous becomes clouded and can not transmit light resulting to loss of vision.Another consequence of vitreous hemorrhage is the formation of fibrous scar tissue which may place traction on the retina resulting in retinal detachment and subsequent visual loss.
Clinical manifestations of retinopathy is a painless process. In non proliferative and preproliferative retinopathy blurry vision secondary to macular edema occurs in some patients, although many patients are asymptomatic. Even patients with a significant degree of proliferative retinopathy and some hemorrhages May not experience major visual changes. However, symptoms indicative of hemorrhage include floaters or cobwebs in the visual field or sudden visual changes including spotty or hazy vision or complete loss of vision.
How to diagnose retinopathy in diabetes?
Diagnosis is by direct visualisation with an ophthalmoscope or with a technique known as fluorescein angiography. This technique can document the type and activity of the retina.
The first focus of management is on primary and secondary prevention. Type 1 management includes maintenance of blood glucose to a normal or near normal level through the intensive insulin therapy and patient’s health education while in type 2, its managed with better control of blood glucose levels.For advanced cases the main treatment of diabetic retinopathy is argon laser photo coagulation.
The laser treatment destroys leaking blood vessels and areas of neovascularization. This reduces the rate of progression of blindness. When there is a major haemorrhage into the vitreous occurring the fluid becomes mixed with blood and prevents light from passing through the eye causing blindness. A vitrectomy is a surgical procedure in which vitreous humor filled with blood or fibrous tissue is removed with a special drill-like instrument replaced with saline or another liquid performed on patients who already have visual loss or blindness.
Other strategies that may slow diabetic retinopathy are:
- Control of hypertension.
- Control of blood glucose levels
- Cessation of smoking.
Early prevention is highly recommended and this can be achieved by implementing the individual plan care and providing diabetic patients with health education. Health education focuses on preventing the occurrence of diabetes complications through ophthalmologic examination and blood glucose control aSs well as self management of eye care regimens. The effectiveness of early diagnosis and prompt treatment is emphasized in teaching patients. Changing of nutritional habits such as high consumption of vitamin D, eating meals with low fats and cholesterol levels, avoiding animal proteins, embracing vegetables and fruits as well as whole grains meals with high fiber and cutting down refined carbohydrates and sweets.
Above all, stay positive. The good habits you adopt today can help you enjoy an active and healthy life with diabetes.
By Clara Kamau