Original Research Article DOI: 10.18231/2395-1451.2018.0015 Indian Journal of Clinical and Experimental Ophthalmology, January-March 2018;4(1):60-66 60 Comparison of ocular blood flow by doppler evaluation in middle aged type 2 diabetes patients with and without diabetic macular edema Piyali Sarkar 1 , Sripurna Ghosh 2,* 1 Associate Professor, 2 Post Graduate, Dept. of Opthalmology, North Bengal Medical College, West Bengal, India *Corresponding Author: Email: sripurna.ghosh@gmail.com Abstract Introduction: The World Health Organization (WHO) has estimated that the number of people diagnosed with Diabetes is 347 million worldwide. Diabetic macular edema (DME) and Diabetic Retinopathy are the main causes of vision loss in Diabetes mellitus. Objective: To compare altered ocular blood flow by Doppler evaluation in middle aged type 2 diabetic patients with and without diabetic macular edema. Materials and Methods: An analytical Cross – Sectional Study was conducted in the out patient and in patient Department of Ophthalmology and the Department of Radiodiagnosis in a tertiary care hospital including 36 patients in each group (A-with DME & B-without DME). Color doppler was done to evaluate ocular blood flow velocities in Internal carotid, ophthalmic and central retinal arteries and central retinal vein. Results: The majority of diabetes patients in developing countries are middle aged (45–64 years of age). Vascular changes and subsequent ocular hemodynamic changes are critical events in the pathogenesis of diabetic retinopathy. Mean Resistivity Index (RI) and Mean Pulsatility Index (PI) in the ophthalmic artery were found to be significantly high in the DME group. Mean end diastolic velocity (EDV) in the common carotid artery was found to be significantly high in the NO DME group than the DME group. In our study, the mean values of Low Density Lipoprotein (LDL) (mg/dl), Total cholesterol (mg/dl), Serum urea (mg/dl), Serum creatinine (mg/dl) was found to be higher (Statistically significant) in the DME group as compared to NO DME group. Conclusion: Our findings may indicate disturbances of retinal and choroidal circulation in patients with DME. Further studies with larger groups of patients are needed to understand better the role of retrobulbar hemodynamics in the pathogenesis of Diabetic macular edema. Keywords: Diabetic macular edema, Ocular blood flow, Doppler evaluation. Introduction Diabetes mellitus (DM) refers to a group of common metabolic disorders that share the phenotype of hyperglycemia. The World Health Organization (WHO) has estimated that the number of people diagnosed with Diabetes is 347 million worldwide (updated November 2014). 1 India leads the world with largest number (31.7 million) of diabetic subjects earning the dubious distinction of being termed the “diabetes capital of the world”. 2 There are many risks factors of type 2 diabetes mellitus embedded in nature (genetic) as well as nurture (i.e. environmental factors including intrauterine environment) like obesity, physical inactivity, lipid profile abnormalities, 3 hypertension, 4 dietary habits. Other factors like family history, genetic factors and birth weight also play a role. The vascular complications of Diabetes Mellitus are subdivided into microvascular (retinopathy, neuropathy, nephropathy) and macrovascular complications [coronary heart disease (CHD), peripheral arterial disease (PAD), cerebrovascular disease]. The risk of complications increases as a function of the duration and degree of hyperglycemia. A reduction in chronic hyperglycemia prevents or delays its complications. Diabetic retinopathy [DR] is the most common ocular complication in Diabetes Mellitus. 5 Worldwide, 93 million people have diabetic retinopathy (DR), including 21 million with Diabetic Macular Edema (DME); another 300 million people are at risk. 6 The reported prevalence of diabetic retinopathy (DR) in diabetics varies substantially between studies, but is probably around 40%. It is more common in type 1 diabetes than in type 2 and sight-threatening disease is present in up to 10%. Diabetic macular edema and Diabetic Retinopathy are the main causes of vision loss in Diabetes mellitus. Diabetic retinopathy is the progressive dysfunction of the retinal vasculature caused by chronic hyperglycemia characterized by microaneurysms, retinal hemorrhages, retinal lipid exudates, cotton-wool spots, capillary nonperfusion, macular edema, neovascularization. 7 Over time, hypoxia causes increased Vascular Endothelial Growth Factor (VEGF) levels in retinal tissue, leading to formation of new vessels, increased vascular permeability and accumulation of fluid. Theoretically, aldose reductase, (VEGF) and platelet abnormalities are said to play a role in the pathogenesis. The best predictor of diabetic retinopathy is the duration of the disease. 8 It is a stronger predictor for proliferative disease than for maculopathy. Raised glycated hemoglobin (HbA1c) is associated with an increased risk of proliferative disease. Improved glycemic control also slowed the progression of early diabetic complications. 9 Strict blood pressure control