Both MCV and RDW correlated positively with HbA1c (r = 0,468, p = 0.003 and r = 0.521, p < 0.001), while Cox regression analysis revealed that besides age, diabetes duration, HbA1c, hypertension and dyslipidemia presence, MCV and RDW are also associated with the risk of DR development and progression (HR 1.057 and 1.237, p < 0.001).CONCLUSIONSWe clearly demonstrated that RBC's characteristics might represent a risk factor for DR development and progression.