Purpose: To investigate the effect of early-scatter laser photocoagulation on the formation of collateral vessels in branch retinal vein occlusion.
Methods: The medical records of 40 cases (40 patients) of branch retinal vein occlusion with macular edema were retrospectively reviewed. Of them, 23 patients were treated with intravitreal bevacizumab injection and 17 patients underwent intravitreal bevacizumab injection with additional laser treatment. Early-scatter laser photocoagulation was applied for capillary non-perfusion areas, regardless of retinal neovascularization. Collateral vessel presence, recurrence rate of macular edema, and number of intravitreal bevacizumab injections were compared between the groups.
Results: During the follow-up period, collateral vessel formation was noted in 10/23 eyes (43.5%) in the intravitreal bevacizumab injection group and 15/17 eyes (88.2%) in the laser combined treatment group (p = 0.004). The recurrence rate of macular edema was lower in the laser combined treatment group (29.4%) than in the intravitreal bevacizumab injection group (65.2%); this difference was statistically significant (p = 0.025). The average numbers of intravitreal bevacizumab injections were 3.57 ± 3.23 in the intravitreal bevacizumab group and 2.14 ± 2.26 in the laser combined treatment group (p = 0.044).
Conclusion: Early-scatter laser photocoagulation promotes collateral vessel formation; the presence of collateral vessels seemed to affect the course of macular edema in branch retinal vein occlusion. Combined early-scatter laser photocoagulation treatment after intravitreal bevacizumab injection lowered the recurrence rate of macular edema and number of intravitreal bevacizumab injections in the cases of branch retinal vein occlusion.
Keywords: Branch retinal vein occlusion; collateral vessels; scatter laser photocoagulation.