Background and aim To investigate the long term effectiveness of grid laser photocoagulation (GLP) versus intravitreal bevacizumab (BEV) in macular oedema (MO) secondary to branch retinal vein occlusion (BRVO), and to evaluate the treatment courses after treatments were switched.

Methods In this prospective interventional consecutive case series, previously untreated eyes with perfused MO were enclosed over a period of 16 months for BEV and for 29 months for GLP. The follow-up period was 1 year. Patients with persistent MO after 12 months of BEV were offered GLP and vice versa, and were followed-up for another 12 months.

Results Both BEV (23 eyes) and GLP (21 eyes) caused a significant (p<0.05) reduction in central retinal thickness (CRT) at 12 months although this was delayed with GLP. However, BEV revealed a significantly better best corrected visual acuity (BCVA) compared with GLP (0.2 vs 0.5 logMAR; p<0.04). Switching therapy for non-responders revealed a reduced CRT at another 12 months, although this was not significant.

Conclusions Functionally and anatomically, BEV appears to be more effective than GLP for the therapy of MO due to BRVO. BCVA is significantly better after 1 year and the anatomical response of the MO is faster. Furthermore, non-responders with persistent MO despite BEV or GLP treatment might benefit from switching therapy.