Blindbæk SL, et al. - Researchers conducted this 3-month prospective study to explore the relationship between oxygen saturations in retinal vessels and the number of diabetic retinopathy (DR) lesions on ultra-wide field color fundus photographs prior to anti-vascular endothelial growth factor (VEGF) treatment and to compare changes in oxygen saturations in retinal vessels with changes in the number of DR lesions following a loading dose of three monthly intravitreal injections of 2.0 mg of aflibercept. The sample consisted of 37 eyes of diabetic macular edema (DME) patients and varying severity of peripheral DR lesions. According to results, baseline retinal arteriolar oxygen saturation increased with increasing DR severity and numbers of microaneurysms, hemorrhages, and cotton wool spots, whereas no relationship was discovered between the severity of DR lesions and retinal venular oxygen saturation. The data presented in this work showed that structural DR lesions correlate with retinal arteriolar oxygen saturation in DME patients before anti-VEGF treatment and that improvement in the severity of DR lesions that occur during intravitreal therapy without corresponding changes in retinal oxygen metabolism. Findings suggested that after initiation of intravitreal therapy, the severity of DR on color fundus photographs should be viewed with caution.