Summary:The purpose of this study was to prospectively evaluate the retinal and optic nerve changes in patients undergoing high-dose chemotherapy (HDC) followed by autologous hematopoietic progenitor cell support (AHPCS). One hundred and forty patients undergoing HDC and AHPCS underwent extensive pre-and post-transplant ophthalmologic evaluations for development of retinal microvascular complications. One hundred and ten patients received high-dose cyclophosphamide, cisplatin and BCNU; thirty received identical doses of cyclophosphamide and cisplatin, but received paclitaxel instead of BCNU. Thirty-four patients (24%) had retinal findings of either cotton wool spots (CWS) (n = 20) or retinal hemorrhages (n = 18) during follow-up, which ranged from 1 to 12 months. Ten (7%) of these patients, all of whom received BCNU, showed ocular toxicity characterized by CWS 1 to 4 months post transplant (n = 10); optic disc edema (n = 3); and variable vision loss associated with the onset of BCNU-induced pulmonary toxicity. Retinal and optic disc microvascular complications may occur after high-dose chemotherapy followed by AHPCS. The association of ischemic retinal lesions and/or optic disc edema with BCNU-induced pulmonary toxicity and the lack of ocular toxicity in patients that did not receive BCNU may suggest that BCNU is the etiologic agent.