The influence of different types of collateral vessels on the recurrence of macular edema in branch retinal vein occlusion.

PURPOSE: To examine the influence of different types of collateral vessels (CVs) on the recurrence of macular edema (ME) in branch retinal vein occlusion (BRVO), and explore other CV characteristics associated with BRVO-ME recurrence.

METHODS

CVs were divided into superficial vascular complex (SVC) type and deep vascular complex (DVC) + SVC type by wide field swept-source optical coherence tomography angiography (OCTA). The proportion of recurrent ME, the number of anti-vascular endothelial growth factor (VEGF) injections, and CV characteristics were compared between the eyes with different types of CVs in BRVO during the 6-month observation period. The influence of CVs related characteristics on ME recurrence in BRVO were analyzed.

RESULTS

Forty-eight BRVO eyes with ME (36 with DVC + SVC type CVs and 12 with SVC type CVs) were retrospectively included. Eyes with DVC + SVC type CVs showed a higher incidence of recurrent ME, more anti-VEGF injections, larger non-perfusion area (NPA), and longer collateral vessel length (CVL) than eyes with SVC type CVs (all P < 0.05). Multiple regression analyses showed that CVs of DVC + SVC type, shorter distance from CVs to the macular fovea (DCMF), and lower curvature of the veins proximal to CVs (CVPC) were significantly associated with the recurrence of ME in BRVO (all P < 0.05).

CONCLUSIONS

Eyes with DVC + SVC type CVs are more likely to develop the recurrence of ME than eyes with SVC type CVs, and shorter DCMF and lower CVPC can also make ME more prone to recurrence in BRVO.