. Author manuscript; available in PMC: 2014 Apr 1.

Published in final edited form as: Ophthalmology. 2013 Jan 26;120(4):724–730. doi: 10.1016/j.ophtha.2012.09.056

Table 1.

Characteristics of the dataset within each geographical zone.

Zone	Subjects	Visits	IOP IOP (mmHg)		MD (dB)
Zone	Subjects	Visits	Mean	95% CI ^A	Mean	95% CI ^A
Atlantic	397	7798	20.0	10.8, 29.3	−0.31	−4.37, 3.75
Central	291	5795	20.7	12.1, 29.3	−0.49	−5.20, 4.23
North	213	4402	19.7	11.8, 27.7	−0.21	−4.19, 3.78
Pacific Northwest	117	2239	19.7	12.5, 27.0	0.02	−3.37, 3.40
Southeast	269	5510	19.0	10.2, 27.8	−0.32	−4.57, 3.92
West	401	8129	19.6	11.4, 27.8	−0.05	−4.29, 4.19

The 95% confidence intervals for Intraocular Pressure (IOP) and perimetric Mean Deviation (MD) are based on an assumption of normality.