It has been reported that hyperbaric oxygen treatment improves visual function in patients with chronic macular edema associated with retinal vein occlusion. This study was designed to investigate relationship between visual prognosis and characteristics of macular edema. From fluorescein angiography performed prior to the therapy, areas of capillary closure and fluorescein leakages were quantitatively evaluated within 1 disc diameter from the fovea. In 27 eyes for which good angiograms were available, 19 eyes were classified as having mild ischemia 1 (area of capillary closure < 25%) and 8 eyes were classified as having severe ischemia (closure area < or = 25%). Of the 27 eyes, 14 showed visual improvement after the therapy. While only one eyes (13%) had visual improvement in the severe ischemic group, 11 eyes (58%) showed visual improvement in the mild ischemic group. The degree of fluorescein leakage before the therapy had no effect on visual outcome. The degree of macular ischemia was found to be a more significant factor influencing visual prognosis after the treatment than the degree of macular edema. Miyamoto, Ogura, Honda, , , , , , (1995). [Hyperbaric oxygen treatment for macular edema after retinal vein occlusion–fluorescein angiographic findings and visual prognosis]. Nippon Ganka Gakkai zasshi, 1995 Feb;99(2):220-5. https://www.ncbi.nlm.nih.gov/pubmed/7701995