Photothermally-induced disordered patterns of corneal collagen revealed by SHG imaging.
The loss of organization of the corneal collagen lattice induced by photothermal effects was analyzed by using second-harmonic generation (SHG) imaging. Porcine cornea samples were treated with low-power laser irradiation in order to get localized areas of tissue disorganization. The disorder induced within the irradiated area of corneal stroma was quantified by means of Discrete Fourier Transform, auto-correlation and entropy analyses of the SHG images. Polarization modulated SHG measurements allowed to probe the changes in the structural anisotropy of sub-micron hierarchical levels of the stromal collagen. Our results emphasize the great potential of the SHG imaging to detect subtle modifications in the collagen assembly. The proposed analytical methods may be used to track several genetic, pathologic, accidental or surgical-induced disorder states of biological tissues.
Matteini
Paolo
P
Istituto di Fisica Applicata Nello Carrara, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, Sesto Fiorentino, I-50019, Italy.
Ratto
Fulvio
F
Rossi
Francesca
F
Cicchi
Riccardo
R
Stringari
Chiara
C
Kapsokalyvas
Dimitrios
D
Pavone
Francesco S
FS
Pini
Roberto
R
D000818:Animals; D003094:Collagen / Q000032:analysis* / Q000528:radiation effects* / Q000648:ultrastructure; D003315:Cornea / Q000166:cytology / Q000528:radiation effects* / Q000648:ultrastructure; D005583:Fourier Analysis; D007834:Lasers; D008027:Light; D034421:Sus scrofa; D013696:Temperature
D003094:Collagen