Molecular Vision: Hayes, Mol Vis 2011; 17:3107-3115. Table 1

Table 1. The effect of Ultraviolet-B (UVB) exposure and normal (+)/deficient (-) dietary ascorbic acid (AA) on the average fibril separation distance, fibril diameter and D-period of stromal collagen in the guinea pig cornea.

Specimen	FSD (nm)	Mean (nm)	Diameter (nm)	Mean (nm)	D-period (nm)	Mean (nm)
Group A (AA+,UVB-)
E*	69.1±1.9	68.1±4.5a	39.3±1.5	38.7±1.3e	64.2±0.5	64.2±0.5
F*	72.5±1.9		38.5±1.1		64.2±0.5
G	62.7±2.1		38.5±1.4		64.2±0.5
Group B (AA-,UVB-)
H	66.7±2.7	65.9±2.5b	38.8±0.5	37.7±1.3 f	64.2±0.5	64.2±0.5
I	65.1±2.0		36.6±0.7		64.2±0.5
Group C (AA+,UVB+)
J*	68.7±1.3	67.5±2.6c	38.1±1.1	38.2±0.9g	64.2±0.5	64.2±0.5
K*	64.6±1.0		38.0±0.3		64.2±0.5
L	69.2±2.3		38.5±1.0		64.2±0.5
Group D (AA-,UVB+)
M	59.6±1.4	62.5±2.7d	38.2±0.6	38.5±0.9h	64.2±0.5	64.2±0.5
N*	64.6±2.3		38.8±0.9		64.2±0.5
O*	63.2±1.3		38.5±1.1		64.2±0.5

Fibril separation distances (FSD), fibril diameters and D-periodicity are averages (±SD) of 12 measurements taken at equal intervals in the central region of each cornea. Means are the averages for each treatment group. Superscript letters a-h show where statistical differences exist between groups: a-d, b-d, c-d, e-f,=p<0.001; a-b, f-h=p<0.01; b-c=p<0.05. No significant differences existed between a-c, e-g, e-h, f-g and g-h. Asterisks are used to indicate left/right pairs of corneas within a treatment group.