Another essential aspect in the treatment of PDR is to be able to give the right diagnosis and to evaluate the efficacy of laser treatment. So far, this has been performed by fluorescein angiography. However, this examination are highly person-dependent and unpleasant to patients, and a more objective approach is needed. Optical coherent tomography angiography (OCT-A) is a quick, noninvasive scanning of the retina which is ideal to visualize moving objects like blood within the retinal vessels. The method has been successfully implemented in a number of retinal diseases, but it has never been validated in PDR.