TABLE 1.

Means and standard deviations and statistical comparison for different ethnicity and gender groups for optic nerve parameters.

	Asian				Caucasian
	Male (n = 32)		Female (n = 35)		Male (n = 32)		Female (n = 34)		p Value
Parameter	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Gender	Ethnicity	Different pattern between males and females in two ethnicities
Age	32.19	15.25	31.49	14.92	33.53	13.75	33.59	14.92	0.90	0.50	0.88
Disc area (mm2)	1.58	0.33	1.80	0.32	1.63	0.26	1.53	0.30	0.21	0.13	0.009
Cup area (mm2)	0.60	0.34	0.71	0.41	0.45	0.32	0.51	0.31	0.066	0.001	0.81
Rim area (mm2)	0.98	0.25	1.06	0.35	1.13	0.33	1.00	0.29	0.59	0.33	0.049
Cup volume (mm3)	0.12	0.09	0.17	0.16	0.08	0.07	0.11	0.12	0.086	0.001	0.98
Rim volume (mm3)	0.14	0.07	0.12	0.09	0.18	0.11	0.11	0.05	0.002	0.17	0.36
Cup disc ratio	0.37	0.16	0.40	0.20	0.28	0.16	0.31	0.16	0.29	0.008	0.68
Retinal nerve fibre layer thickness (µm)
Mean	118.0	14.41	115.0	16.45	117.0	13.83	119.8	12.30	0.83	0.58	0.19
Temporal	74.2	13.37	73.1	13.36	68.9	10.24	70.1	13.90	0.98	0.07	0.59
Superior	135.2	19.75	132.0	23.57	131.2	15.97	135.8	14.97	0.80	0.96	0.23
Nasal	95.4	21.47	92.8	21.41	99.0	19.58	97.3	20.42	0.56	0.29	0.91
Inferior	135.1	15.93	133.4	19.74	134.8	17.17	137.21	18.25	0.92	0.56	0.50

Rim volume was significantly larger in males, whereas cup volume and area and cup/disc ratio was significantly larger in Indians. The interaction term (gender × ethnicity) indicates a different pattern between males and females in the two ethnic groups and was statistically significant for disc and rim areas.