Figure 6. SHG imaging of the infected rabbit cornea in vivo.

(A) XY slice showing PA (green) localization within bands of collagen in an apparent linear structure. (B) PA combined with forward SHG signal (red). (C) XZ slice showing the distribution of PA within discrete bands throughout the mid-stromal region. A smaller band (*) was apparent in the mid-stroma, and a larger band (arrowhead) was present more posteriorly. (D) XY slice corresponding to asterisk region in C showing linearized organization of PA. (E) XY slice corresponding to arrowhead region in C showing the linearized organization of PA. Scale bar: 50 μm. (F) Directionality analysis of segmented region (256 × 256 pixels) isolating the areas of banding showed a small, but significant correlation between the relative alignment of PA and collagen fibrils (R = 0.389 ± 0.171, P < 0.001). Depending on the plane depth, R values ranged from 0.209 to 0.668. In areas outside of the yellow banding, no significant correlation was detected. Data representative of 3 independent rabbits.