DR/DME Prevalence and Risk


Globally 35.4% of  patients with diabetes present with some form of Diabetes-related Retinopathy, and 7.5% of patients present with Proliferative Diabetes-related Retinopathy. The incidence was found to be higher in  patients with type 1 diabetes with 77.3% of patients displaying some form of Diabetes-related Retinopathy and 32.4% displaying Proliferative Diabetes-related Retinopathy. For patients with Type 2 Diabetes 25.2 % showed some form of Diabetes-related Retinopathy and 3.0% displayed Proliferative Diabetes-related Retinopathy. There are approximately 93 million people with Diabetes-related Retinopathy, 17 million with Proliferative Diabetes-related Retinopathy, 21 million with Diabetes-related Macular Edema, and 28 million with vision-threatening Diabetes-related Retinopathy worldwide 3.

Figure: Diabetes-related Retinopathy is the primary cause of blindness in adults aged 20-74 years.

Risk Factors

Non-modifiable risk factors of Diabetes-related Retinopathy and Diabetes-related Macular Edema include:

Duration of diabetes: almost all patients with type 1 diabetes develop some form of Diabetes-related Retinopathy if duration of diabetes is long enough, and this is independent of glycemic control.

Puberty is a well-known risk factor for Diabetes-related Retinopathy in type 1 diabetes. Onset of diabetes during pubertal or post-pubertal age increases risk of developing severe retinopathy particularly in males.

Pregnancy can rapidly progress Diabetes-related Retinopathy and Diabetes-related Macular Edema, especially in patients with type 1 diabetes. A recent study found progression of Diabetes-related Retinopathy in pregnancy to be almost 3 times as likely to occur in mothers with type 1 diabetes as mothers with type 2 diabetes. This progression is often transient and accompanied by rapid regression of Diabetes-related Retinopathy in the postpartum period.

The ADA recommends that women with diabetes have an eye exam before becoming pregnant or during the first trimester of pregnancy and be closely followed during the pregnancy and up to one year after giving birth. Pregnancy can sometimes cause diabetes-related retinopathy to develop or worsen.

Nephropathy (kidney disease) and cardiovascular disease or heart disease also increase your risk.

Modifiable Risk Factors for Diabetes-related Retinopathy and Diabetes-related Macular Edema include:

Hyperglycaemia: glycemic stability (HbA1c <7 %) reduces the risk of development and progression of Diabetes-related Retinopathy in both type 1 and type 2 diabetes. According to The Diabetes Control and Complications Trial, controlling diabetes and maintaining the HbA1c level in the 6-7% range can substantially reduce the progression of diabetes-related retinopathy. Glycemic stability is much more effective in preventing or delaying the onset of Diabetes-related Retinopathy in patients with diabetes without Diabetes-related Retinopathy, rather than limiting the severity of Diabetes-related Retinopathy after it has occurred. Glycemic stability reduced the incidence of retinopathy by 76 % and progression from early to advanced retinopathy by 54 %. Glycemic stability should be achieved early in the disease course and maintained for as long as possible, since its protective effect is sustained even if tight glycemic stability is lost. Metabolic memory is a term used to describe beneficial effects of immediate intensive treatment of hyperglycemia and the observation that they are maintained for many years, regardless of glycemia in the later course of diabetes.

Hypertension: A Cochrane systematic review in 2015 concluded that intensive blood pressure control had a modest effect in reducing incidence of Diabetes-related Retinopathy, but does not reduce risk of progression 4.

Dyslipidemia: The evidence for dyslipidemia as a risk factor for Diabetes-related Retinopathy are inconsistent, and no single lipid measure had been consistently found to be associated with Diabetes-related Retinopathy and Diabetes-related Macular Edema.

Obesity: The effect of obesity on Diabetes-related Retinopathy has been well studied, however, there are inconclusive and conflicting findings suggesting that obesity with Type 1 Diabetes increases risk while obesity with type 2 diabetes confers a reduced risk.

Ethnicity: The prevalence of Diabetes-related Retinopathy, sight-threatening Diabetes-related Retinopathy, and clinically significant Macular Edema are higher in people of South Asian, African, Latin American, and indigenous tribal descent compared to the Caucasian population 5.

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