PDR is traditionally perceived as an ischemic disease, which initially affects the entire retina. In our above mentioned study the investigators were able to confirm the results regarding the venous retinal oxygen saturation in the affected segment of the retina, in 24 of the patients in the study, who had only one peripheral proliferation. In these patients the oxygen saturation was increased with disease progression (+ 3.9% vs. -1.5%, p = 0.04). This indicates that the focal hypoxia are more important than previously thought, and thus the local treatment of the diseased area may be a treatment option that reduces the processing volume, thereby minimizing potential side effects.