Three-dimensional angiographic imaging of leakage in branch retinal vein occlusion

Optical coherence tomography (OCT) is used to image branch retinal vein occlusion (BRVO) but lacks information about leakage dynamics and perfusion status. Topographical angiography (TAG) is capable of providing this information and has been described previously in age-related macular degeneration. This study evaluates TAG in BRVO.

We included 56 eyes of 40 consecutive patients with BRVO and a reduction in central vision. Two groups were established based on whether argon laser coagulation was performed or not. A standardized follow-up was performed. The chorioretinal fluorescence pattern was reconstructed following TAG. Quantitative measurements were also performed.

TAG performed from indocyanine green angiography (ICGA) showed smaller lesion size (LS) compared to fluorescein angiography (FA) (mean difference: early phase = -1.6 mm(2), late phase = -1.8 mm(2)). The extent of mean LS from early to late phase increased by 0.8 mm(2) in FA and by 0.6 mm(2) in ICGA. TAG could visualize different degrees of leakage topographically.

TAG gives new insights into the pathophysiology of BRVO: it enables the visualization of dynamics of leakage and the demonstration of the effects of intravasal stasis. Furthermore, TAG is less impaired by masking phenomena than FA. Functional retinal imaging shows distinct advantages over OCT: quantification of leakage activity is possible using TAG.