This trial aims to investigate the effect of patient's own bone marrow stem cells in the treatment of retinopathy due to type 1 diabetes. The trial being conducted by the Teheran University of Medical Sciences and expects to enrol 20 patients by end 2013. All participants will have stem cells harvested from their bone marrow and expanded in the laboratory before being intravenously (IV) transfused into the participants. Participants will be monitored for complications and improvements in their condition.