IMPETUS 2018 - TREAT is the second of two studies aimed at making an individual design for retinal laser treatment. In IMPETUS 2018 - DETECT the investigators demonstrated that non-invasive examinations of the oxygen level and measurements of the retinal vascular tree provide important information of individual treatment response. For instance, if standard PRP led to three per cent higher retinal oxygen saturation, there was a 4-fold risk of disease progression despite treatment. Hence, such a patient would benefit from more treatment to avoid blindness. With these observations at hand, the investigators want to compare a less invasive treatment (individualized laser treatment) against the standard PRP.