Purpose: To analyse the efficacy and outcome predictors of ranibizumab using a spectral-domain optical coherence tomography (SD-OCT)-driven treat-and-extend regimen (TER) versus SD-OCT-driven pro re nata regimen (PRN) in patients with cystoid macular oedema (CME) due to branch or central retinal vein occlusion (BRVO, CRVO). Methods: Retrospective, consecutive case series. Evaluation included best corrected visual acuity (BCVA), morphological parameters on SD-OCT, and treatment frequency. Results: From baseline to months 12, 18, and 24, BCVA improved by 16.6 ± 13.1, 15.5 ± 14.4, and 16.6 ± 15.8 letters, respectively, in TER (n = 45), compared to 11.3 ± 17.0, 11.0 ± 15.0, and 10 ± 20.5 letters in PRN (n = 31) (p = 0.152, p = 0.237, p = 0.172). The mean reduction in central retinal thickness was –261 ± 189, –272 ± 188, and –264 ± 158 μm, respectively, in TER, compared to –130 ± 196, –140 ± 210, and –166 ± 207 μm in PRN (p = 0.006, p = 0.017, p = 0.064). 59% (53%) of TER and 22% (17%) of PRN patients showed no intra- or subretinal fluid on SD-OCT at 12 (24) months. Using TER, the maximum recurrence-free treatment interval increased from 8.9 ± 2.3 weeks at 12 months to 9.8 ± 2.3 and 10.5 ± 2.7 weeks at 18 and 24 months, respectively. The number of injections was significantly higher in the TER than in the PRN group. Conclusions: In CME, due to BRVO/CRVO, TER provides better morphological outcome using more injections than PRN.