Table 5. Comparison of the peripapillary retinal nerve fibre layer thickness between primary open-angle glaucoma patients and normal controls (μm, mean ± SD).

	POAG	Normal	Reduction rate (%)*	P value†
Average RNFL thickness	64.8 ± 11.7	92.6 ± 8.2	30.0	<0.001
Quadrant RNFL thickness
Superior	77.1 ± 18.9	113.6 ± 13.9	32.1	<0.001
Nasal	58.0 ± 8.8	68.8 ± 10.5	18.6	<0.001
Inferior	71.5 ± 21.8	119.7 ± 13.7	40.2	<0.001
Temporal	53.0 ± 13.4	68.2 ± 11.3	22.3	<0.001
Clock-hour RNFL thickness
11 o’clock	75.4 ± 23.1	122.3 ± 17.2	38.4	<0.001
12 o’clock	79.6 ± 22.0	118.5 ± 26.2	32.7	<0.001
1 o’clock	76.4 ± 21.7	100.1 ± 17.8	23.7	<0.001
2 o’clock	68.5 ± 15.8	83.9 ± 16.5	18.4	<0.001
3 o’clock	52.2 ± 10.0	58.5 ± 10.6	10.8	<0.001
4 o’clock	53.2 ± 9.1	64.2 ± 11.6	16.8	<0.001
5 o’clock	67.2 ± 14.0	94.9 ± 16.5	29.2	<0.001
6 o’clock	75.2 ± 21.2	128.8 ± 20.5	41.6	<0.001
7 o’clock	72.3 ± 25.4	137.3 ± 16.7	47.3	<0.001
8 o’clock	52.9 ± 13.2	70.4 ± 13.5	24.9	<0.001
9 o’clock	49.3 ± 12.7	54.0 ± 9.6	8.5	0.004
10 o’clock	56.7 ± 17.6	78.7 ± 11.9	28.0	<0.001

RNFL = retinal nerve fibre layer, GCIPL = ganglion cell plus inner plexiform layer

POAG = primary open-angle glaucoma

*Reduction rate (%) = 100 × (RNFL thickness of the normal eye–RNFL thickness of the POAG eye)/RNFL thickness of the normal eye

† Axial length adjusted analysis of covariance.