Table 3 Comparison of PCI values at the same level of IOP within the range 16 to 29 mm Hg.

IOP (mm Hg)	Normal		NTG		p
	n	PCI (mean±SD)	n	PCI (mean±SD)
16–17	43	101.6±22.6	13	115.0±17.2	0.0071
18–19	34	109.6±23.6	15	123.4±26.6	0.069
20–21	19	117.9±19.2	23	143.9±23.8	0.0003

IOP (mmHg)	OHT		POAG		p
	n	PCI (mean±SD)	n	PCI (mean ± SD)
22–23	28	120.1±19.1	30	157.8±31.1	<0.001
24–25	18	138.4±30.4	15	160.9±37.7	0.0780
26–27	15	143.7±28.1	17	175.3±36.3	0.0109
28–29	11	146.2±20.9	10	176.4±22.4	0.0024