View 1: should this patient receive laser treatment?

In patients with diabetic retinopathy, laser treatment is directed at the prevention of visual loss rather than at visual improvement. Treatment should therefore be applied before visual loss occurs, when the risk of visual loss justifies adverse effects of treatment. The risk of visual loss is linked to the likelihood of progression of retinopathy to sight threatening forms, which in turn depends on epidemiological factors such as sex, ethnicity, diabetes type, and duration; systemic factors such as hypertension, glycaemic control, and serum lipids; specific risk factors such as pregnancy, cataract surgery, and tightened glycaemic control; and, lastly, ophthalmoscopic signs (box 1). ### Box 1 Factors influencing progression of diabetic retinopathy Epidemiological factors (immutable) Diabetes type, diabetes duration, ethnicity, sex Systemic factors (modifiable) Glycaemic control, hypertension, serum lipids, renal dysfunction Specific risk factors (timeable) Pregnancy, cataract surgery, tightened glycaemic control Ophthalmoscopic signs This patient has type 2 diabetes, and data from the Wisconsin Epidemiological Study …