Both the incidence and prevalence of diabetic retinopathy are highest in type 1 diabetic patients with an early age of onset of diabetes. However, type 1 diabetic patients do not exhibit retinopathy at presentation, and the likelihood of developing significant diabetic eye disease in the first 5 years of the disease is small.
In contrast, type 2 diabetic patients may have retinopathy at presentation, presumably because they have had previously unrecognized type 2 diabetes for many years. The prevalence of retinopathy increases with the duration of diabetes. In general, significant visual impairment is usually caused by proliferative retinopathy in type 1 diabetes and by maculopathy in type 2 diabetes.
Background diabetic retinopathy is characterized by capillary dilatation and occlusion, microaneurysms, 'blot' hemorrhages and hard exudates (which are true exudates of lipid-rich material from abnormal vessels). This picture represents non-proliferative retinopathy and is not associated with visual loss unless hard exu-dates become extensive and involve the fovea. Prepro-liferative lesions, a harbinger of impending new vessel formation, include cottonwool spots, venous loops and beading, arterial narrowing and occlusion, and intraretinal microvascular abnormalities. The latter consist of abnormal dilated capillaries which are often leaky.
The importance of the recognition of preprolifera-tive retinopathy is that it indicates the need for urgent referral to an ophthalmologist. New vessels originate from a major vein (occasionally from arteries) and appear in the retinal periphery or on the optic disc. They are much less common in type 2 diabetes than in type 1 diabetes. New vessels have a devastating impact on vision when they burst and produce sudden pre-retinal or vitreous hemorrhage. Contraction of associated fibroglial tissue may result in retinal detachment with resultant loss of vision, which may be profound if it affects the macula.
Diabetic maculopathy is the most common cause of visual loss in type 2 diabetes and may be exudative, edematous or ischemic. If left untreated, preproliferative retinopathy, proliferative retinopathy and maculopathy will all have an appalling prognosis for the patient's eyesight. All diabetic patients should be regularly screened for such changes and referred, where appropriate, for specialized ophthalmic assessment.
Laser photocoagulation can be used to destroy isolated new vessels or to undertake panretinal photocoagulation in cases of more severe proliferative retinopathy. The aim of the panretinal approach is to reduce retinal ischemia overall, thereby reducing the stimulus to new vessel formation.
Photocoagulation may also be used for the treatment of macular edema, with focal treatment given for discrete lesions and diffuse treatment for widespread capillary leakage and non-perfusion. Vitreoretinal surgery may be performed to treat severe vitreous hemorrhage and retinal detachment.
Detection of diabetic retinopathy at an early stage is essential. All diabetic patients should have regular ophthalmic examination. Screening programs for retinopathy should be designed to include all patients with diabetes in an attempt to avoid visual loss. The combination of direct ophthalmoscopy and digital retinal photography with measurement of visual acuity is often used. Suitably qualified optometrists have also been used in some screening programs.
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All you need is a proper diet of fresh fruits and vegetables and get plenty of exercise and you'll be fine. Ever heard those words from your doctor? If that's all heshe recommends then you're missing out an important ingredient for health that he's not telling you. Fact is that you can adhere to the strictest diet, watch everything you eat and get the exercise of amarathon runner and still come down with diabetic complications. Diet, exercise and standard drug treatments simply aren't enough to help keep your diabetes under control.