From such images, we measured the width of collagen lamellae in 10 assigned layers of the normal corneal stroma between Bowman's layer and Descemet's membrane (L1–L10), as well as of those adherent to Bowman's layer (L0) (
Table 1;
Fig. 3). The mean width ± SD of collagen lamellae at L0 was 6.5 ± 1.7 μm (range, 2.4–11.2), whereas that in L1 (the layer adjacent to Bowman's layer) was smaller at 4.3 ± 1.3 μm (range, 2.1–7.9). The width of the lamellae then gradually increased with tissue depth, consistent with our previous observations for the anterior stroma.
7 The corresponding values for L2 to L10 were thus 11.2 ± 5.3 μm (range, 3.3–24.1), 21.3 ± 10.3 μm (range, 4.9–57.0), 32.6 ± 12.4 μm (range, 5.1–55.9), 48.0 ± 17.8 μm (range, 11.0–85.1), 60.6 ± 15.5 μm (range, 30.6–97.5), 71.0 ± 21.7 μm (range, 35.3–111.6), 84.5 ± 23.2 μm (range, 47.3–136.8), 103.5 ± 29.9 μm (range, 67.8–188.3), and 122.2 ± 34.5 μm (range, 69.1–232.0), respectively. We also measured the angle of collagen lamellae in each layer relative to Bowman's layer (
Table 2;
Fig. 4). The angle (mean ± SD) of collagen lamellae adjacent to Bowman's layer (in L1) was 20.9° ± 5.4° (range, 10.5°–42.5°), whereas the angle of those in L2 decreased to 10.6° ± 3.2° (range, 4.4°–21.0°) and that of those in L3 to L10 then decreased gradually to 6.7° ± 2.8° (range, 0.4°–12.5°), 4.7° ± 2.5° (range, 0.1°–10.4°), 4.0° ± 2.1° (range, 0.1°–8.8°), 3.7° ± 2.1° (range, 0.0°–8.6°), 3.5° ± 1.9° (range, 0.2°–8.6°), 3.3° ± 2.0° (range, 0.1°–10.6°), 3.0° ± 2.0° (range, 0.1°–7.1°), and 2.7° ± 2.2° (range, 0.0°–9.6°), respectively. This decrease in the angle of collagen lamellae with distance from Bowman's layer is also consistent with our previous observations for the anterior stroma.
7