Non- modifiable risk factors of Diabetic Retinopathy and Diabetic Macular Edema:
Duration of diabetes: almost all type 1 diabetic patients develop some form of Diabetic Retinopathy if duration of diabetes is long enough, and this is independent of glycaemic control.
Puberty is a well-known risk factor for Diabetic 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 Diabetic Retinopathy and Diabetic Macular Edema, especially in patients with type 1 diabetes. A recent study found progression of Diabetic 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 Diabetic 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 diabetic retinopathy to develop or worsen.
Nephropathy (kidney disease) and cardiovascular disease or heart disease also increase your risk.
Modifiable Risk Factors for Diabetic Retinopathy and Diabetic Macular Edema:
Hyperglycaemia: tight control of glycemia (HbA1c <7 %) reduces the risk of development and progression of Diabetic 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 diabetic retinopathy. Strict glycemic control is much more effective in preventing or delaying the onset of Diabetic Retinopathy in patients with diabetes without Diabetic Retinopathy, rather than limiting the severity of Diabetic Retinopathy after it has occurred. Intensive glycemic control reduced the incidence of retinopathy by 76 % and progression from early to advanced retinopathy by 54 %. Glycemic control 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 control 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 Diabetic Retinopathy, but does not reduce risk of progression 5.
Dyslipidemia: The evidence for dyslipidemia as a risk factor for Diabetic Retinopathy are inconsistent, and no single lipid measure had been consistently found to be associated with Diabetic Retinopathy and Diabetic Macular Edema.
Obesity: The effect of obesity on Diabetic 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 diabetic retinopathy, sight-threatening diabetic 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 6.