Second-harmonic imaging of cornea after intrastromal femtosecond laser ablation.
Nonlinear laser scanning microscopy is widely used for noninvasive imaging in cell biology and tissue physiology. However, multiphoton fluorescence imaging of dense, transparent connective tissue (e.g., cornea) is challenging since sophisticated labeling or slicing is necessary. High-resolution, high-contrast second harmonic generation (SHG) imaging of corneal tissue based on the intrinsic structure of collagen is discussed. The three-dimensional corneal ultrastructure in depths up to hundreds of microns can be probed noninvasively, without any staining or mechanical slicing. As an important application of second harmonic imaging in ophthalmology, the modification of corneal ultrastructure using femtosecond laser intrastromal ablation is systematically investigated to evaluate next-generation refractive surgical approaches.
Han
Meng
M
University of Heidelberg, Kirchhoff Institute for Physics, Im Neuenheimer Feld 227, D-69120 Heidelberg, Germany. mhan@urz.uni-heidelberg.de
Zickler
Leander
L
Giese
Guenter
G
Walter
Matthias
M
Loesel
Frieder H
FH
Bille
Josef F
JF
D000818:Animals; D002417:Cattle; D003094:Collagen / Q000528:radiation effects / Q000648:ultrastructure*; D003319:Corneal Stroma / Q000601:surgery* / Q000648:ultrastructure*; D048988:Corneal Surgery, Laser / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D066298:In Vitro Techniques; D018613:Microscopy, Confocal / Q000379:methods*; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*
D003094:Collagen