The aim of the guidelines is to provide evidence-based, clinical guidance for the best management of different aspects of diabetic eye disease. The foundations of the guidelines are based on evidence taken form the literature and published trials of therapies as well as consensus opinion of a representative expert panel convened by the Royal College of Ophthalmologists with an interest in this condition. The scope of the guidelines is limited to management of diabetic retinopathy with special focus on sight threatening retinopathy. It offers guidance regarding service set up to facilitate delivery of optimal clinical care for patients with retinopathy. The guidelines are prepared primarily for ophthalmologists, however they are relevant to other healthcare professionals, service providers and commissioning organisations as well as patient groups.