Parapapillary chorioretinal atrophy and parapapillary avascular area in glaucoma

We measured the area of parapapillary chorioretinal atrophy (PPA), i.e. zone alpha and zone beta in fluorescein angiography, and parapapillary avascular area (PPAVA) in indocyanine green angiography, using scanning laser ophthalmoscope in a total of 66 eyes of 39 patients. There were 26 eyes of 16 patients with normal tension glaucoma (NTG) and 40 eyes of 23 patients with primary open angle glaucoma (POAG). Although there was no significant correlation between the areas of PPAVA, PPA, zone alpha or zone beta, and mean deviation of Humphrey field analysis, there was significant correlation between all areas except for zone alpha and the spherical equivalent. The areas of PPAVA and zone beta in the NTG group were significantly larger than those in the POAG group (p = 0.04434, 0.02750, respectively). These results suggest that the pathogenesis of disease may be different in NTG and POAG.