الفهرس 
Type 2 Diabetes MellitusOnly 14 pages are availabe for public view
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Abstract
Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia [fasting plasma glucose≥126 mg/dl (7.0 mmol/l) or 2-h plasma glucose ≥200 mg/dl (11.1 mmol/ l)] resulting from defects in insulin secretion, insulin action, or both. Type 2 diabetes mellitus results from insulin resistance, a condition in which cells fail to use insulin properly, sometimes combined with an absolute insulin deficiency. chronic hyperglycemia leads to multiple organs damage especially the eyes, kidneys, nerves, heart, and blood vessels Diabetic retinopathy (DR), nephropathy and peripheral neuropathy are the common complications of DM. DR is one of the causes of blindness worldwide. There are many risk factors for DR. The duration of DM significantly associated with the development and severity of DR. Significant systemic risk factors include hypertension and high glycosylated hemoglobin A1c (HbA1c), systolic blood pressure, pulse pressure, serum lipoprotein level and body mass index. DR is divided into two main groups namely the non-proliferative diabetic retinopathy (NPDR) and the proliferative diabetic retinopathy (PDR) Changes of the anterior segment structures include vacuolation of the iris pigment epithelium, thickening of the basement membrane of the ciliary processes, thickening of the cornea and cataract formation. Early detection of any changes in anterior ocular segment biometry will help for early intervention and provide effective treatment in order to reduce the risk of vision loss. Several studies have reported thickening of central corneal thickness (CCT) in people with diabetes.
HbA1c is regarded as the gold standard indicator for glycemic control in diabetic patients. It is formed in a non-enzymatic glycation pathway by hemoglobin’s exposure to plasma glucose. Normal levels of glucose produce a normal amount of HbA1c. As the average amount of plasma glucose increases, the fraction of HbA1c increases in a predictable way. This serves as a marker for average blood glucose levels over the previous months prior to the measurement.