Peripapillary crescent enlargement in highly myopic eyes evaluated by fluorescein and indocyanine green angiography.

AIMS To evaluate angiographic features of myopic crescents using fluorescein angiography (FA) and indocyanine green angiography (IA). METHODS FA and IA angiograms of 88 highly myopic eyes (47 consecutive patients) were reviewed. The follow up period ranged from 5-28 years. RESULTS FA revealed two zones of the myopic crescent: a consistently hypofluorescent inner zone and an outer zone with delayed choroidal filling. IA revealed dislocation of the Zinn-Haller ring to the border between the two zones. Myopic crescent enlargement occurred in 68.1%. Only the outer zone increased significantly in most of the eyes with enlarged crescents. CONCLUSIONS The inner zone might develop as a result of mechanical stretching, and the outer zone might be the result a secondary circulatory disturbance and mechanical stretching.