Table 2.

Summary Statistics For Inner And Outer Ratios for the Second Cohort

Parameter	Inner Ratio	Outer Ratio
Mean	0.93	0.91
Standard deviation	0.08	0.09
Median	0.93	0.91
2.5th Centile	0.75	0.76
97.5th Centile	1.09	1.07
Correlation with age (Spearman)	−0.19	−0.19
	(P = 0.073)	(P = 0.080)
Change per decade (standard error)	−0.010	−0.013
	(0.007)	(0.007)

OCTs were obtained with the Topcon device (3D OCT; Topcon Corporation) and segmented with automated software (Orion; Voxeleron LLC). For correlation with age and change per decade, the values from both twins from each twin pair were averaged.