Table 2.

Properties of the Principal Components Derived From the GCL Tissue Volume Profiles Across Subjects

	Shape	Correlation
	Variance	w/Axial
PC	Explained	Length
1	–	0.85***
2	40%	0.75***
3	12%	0.11
4	10%	0.25
5	8%	–0.16
6	5%	–0.13

The first 6 principal components were found to explain 99.5% of the total variance in the data. The first principal component primarily accounts for variation across subjects in the mean tissue volume across the profile. Components 2 to 6 account for 75% of the remaining variation in the shape of the profile across subjects. The Pearson correlation of axial length with the weights on each of the components is also given (*** indicate correlations with significance P < 0.001; the remaining coefficients were found to be nonsignificant).