The evaluation of screening policies for diabetic retinopathy using simulation

Under policy 1, a person was screened using the chosen screening method until background or more advanced DR was detected. The person was then assessed in an outpatient clinic by an ophthalmologist using mydriatic seven-field photography. If retinopathy was confirmed screening was stopped, and if not, it resumed. Patients with background DR were seen at more frequent intervals in the ophthalmic clinic, until they needed photocoagulation for treatable DR. The alternative methods of screening that were considered were: