The present invention relates to the use of hydroxycarbamide (HC) for reducing and/or delaying the extension of capillary nonperfusion, a cause of irreparable visual impairment in patients suffering from central retinal vein occlusion (CRVO). This is the first systemic treatment which makes it possible to reduce retinal ischemic complications in patients in whom (CRVO) has been recently diagnosed and is consequently in a rapidly progressive phase. Given the low toxicity of HC evaluated on a large scale in children and adults in the context of other diseases for decades, the results of the present study open up a new therapeutic approach in the treatment of CRVO.