This study aimed to investigate the effects of ranibizumab on optical coherence tomography (OCT) parameters and the peripheral blood systemic inflammation index in men diagnosed with retinal vein occlusion accompanied by macular edema (BRVO-ME) and explore the relevant factors affecting visual prognosis. The clinical data of men diagnosed with BRVO-ME who underwent vitreous cavity injections of ranibizumab were retrospectively analyzed, and they were stratified into a good prognosis group (defined as a difference ≤−0.3) and a poor prognosis group (defined as a difference >−0.3) based on the difference between the logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) and pre-treatment logMAR BCVA at 6 months post-treatment. After 6 months of ranibizumab treatment, there were significant reductions (p < 0.05) observed in logMAR BCVA, intraocular pressure, center macular thickness (CMT), outer hyperreflective retinal foci (HRFs), inner HRFs, outer membrane (ELM) integrity, elliptical zone (EZ) integrity, as well as serum neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and systemic immune-inflammatory index (SII) levels. Disease duration, ELM integrity, BCVA, outer HRF and serum SII emerged as independent risk factors influencing the prognosis of visual acuity subsequent to ranibizumab treatment in BRVO-ME eyes (p < 0.05). A nomogram prediction model incorporating these risk factors exhibited favorable differentiation and accuracy. In conclusion, disease duration, BCVA, ELM integrity, presence of outer HRF and elevated serum SII were identified as independent risk factors influencing visual prognosis following ranibizumab treatment in male patients with BRVO-ME. Furthermore, the nomogram developed based on OCT parameters and serum SII exhibited favorable differentiation and accuracy.