METHODS By means of video-fluoresce in angiography arm-retina-time (ART) and retinal arteriovenous passage time (AVP) were measured in order to determine the effect of panretinal laser-coagulation on retinal circulation in patients with diabetic retinopathy. 55 patients with either preproliferative (n = 29) or proliferative (n = 26) retinopathy we reexamined before, 3-9 weeks after panretinal laser-coagulation (mean: 848 burns, 0.5 mm diameter), and 0.5-3 years later. RESULTS The ART of the diabetic patients was in the normal range and showed no differences among the three measuring times. The retinal AVP was significantly prolonged in the three measuring times (nasal and temporal) when compared to normals. Laser-coagulation showed no significant effect on AVP in the temporal branches, whereas in the nasal branches AVP decreased from 2.38 +/- 0.69 s (before laser-coagulation) to 2.11 +/- 0.68 s (3-9 weeks after treatment) and 2.06 +/- 0.67 s (0.5-3 years after treatment) (p < 0.01). In branches with neovascularisation (n = 24) a pronounced decrease of AVP from 2.60 +/- 0.70 s to 1.96 +/- 0.61 s and 2.09 +/- 0.64 s (p < 0.01) was detected. CONCLUSIONS Thus, laser-coagulation leads to a faster circulation in areas with laser burns within 3-9 weeks post-treatment.