INDOCYANINE GREEN ANGIOGRAPHY PATTERNS OF ZONES OF RELATIVE DECREASEDCHOROIDAL BLOOD-FLOW IN PATIENTS WITH EXUDATIVE AGE-RELATED MACULAR DEGENERATION

BACKGROUND AND OBJECTIVE: To investigate the incidence and patterns of posterior zones of relative decreased choroidal blood flow in patient s with exudative age-related macular degeneration. PATIENTS AND METHOD S: Digital indocyanine green (ICG) angiograms from 100 patients with e xudative age-related macular degeneration were reviewed for the presen ce of posterior zones of relative decreased choroidal blood flow. The patterns of these zones and their location relative to the choroidal n eovascular process were noted. RESULTS: Ninety-five percent of the ang iograms displayed the presence of either a complete or an incomplete z one of relative choroidal hypoperfusion. The zone was most apparent in the early frames of the angiogram. Five different patterns of relativ e decreased choroidal blood flow were identified: horizontal (32%),ver tical (14%), bipartite (9%),tripartite (31%), and quadripartite (9%). The choroidal neovascular process was located within or at the edge of the zone of relative choroidal hypoperfusion in all cases. CONCLUSION : Most cases of choroidal neovascularization localize to areas of rela tive choroidal dye nonfilling on ICG angiography. These patterns of ch oroidal nonfilling may have implications in the pathogenesis and manag ement of choroidal neovascular membranes in age-related macular degene ration.