Table 7.

Frequency of peripapillary atrophy and impact on diagnostic accuracy in the present study population.

	PPA present				Percentage of Normals with a False Positive Diagnosis of Glaucoma			Percentage of Glaucoma Patients with a False Negative Diagnosis of Glaucoma
	Percentage of subjects	Number of subjects	Normal	POAG	PPA absent	PPA present	p value*	PPA absent	PPA present	p value†
OCA1
Superior	14.1%	22	7	15	21.7%	42.9%	0.345	14.9%	6.7%	0.682
Temporal	27.5%	43	10	33	17.5%	50%	0.038	30.4%	3.0%	0.002
Inferior	16.0%	25	8	17	11.9%	37.5%	0.091	6.9%	5.9%	1
Nasal	8.3%	13	3	10	43.8%	0.0%	0.259	12.7%	10.0%	1
All	16.5%	103	28	75	24.2%	39.3%	0.108	15.3%	5.3%	0.021
OCA2
Superior	7.1%	11	3	8	14.1%	0.0%	1	24.7%	12.5%	0.675
Temporal	16.0%	25	6	19	21.3%	50%	0.142	25.7%	5.3%	0.063
Inferior	6.4%	10	3	7	12.5%	0.0%	1	9.8%	28.6%	0.176
Nasal	4.5%	7	2	5	38.5%	0.0%	0.525	20.2%	40.0%	0.289
All	8.5%	53	14	39	21.7%	21.4%	1	19.9%	15.4%	0.668

PPA: peripapillary atrophy, POAG: primary open angle glaucoma. OCA1: outer circumpapillary annulus of circular grid 1, OCA2: outer circumpapillary annulus of circular grid 2.

^*p values comparing rates of a false positive diagnosis between subjects with and without PPA

^†p values comparing rates of a false negative diagnosis between subjects with and without PPA