The visual prognosis of patients suffering from retinal branch vein occlusion complicated by macular oedema is assessed in relation to the degress of capillary fallout. Extensive retinal capillary fallout associated with macular oedema was found to confer a poor visual prognosis in a series of 89 patients followed for an average time of 14 months. If the degree of capillary fallout associated with marular oedema was minimal, the visual prognosis was considerably improved.