title: Direct trabecular meshwork imaging in porcine eyes through multiphoton gonioscopy.
abstract: The development of technologies to characterize the ocular aqueous outflow system (AOS) is important for the understanding of the pathophysiology of glaucoma. Multiphoton microscopy (MPM) offers the advantage of high-resolution, label-free imaging with intrinsic image contrast because the emitted signals result from the specific biomolecular content of the tissue. Previous attempts to use MPM to image the murine irido-corneal region directly through the sclera have suffered from degradation in image resolution due to scattering of the focused laser light. As a result, transscleral MPM has limited ability to observe fine structures in the AOS. In this work, the porcine irido-corneal angle was successfully imaged through the transparent cornea using a gonioscopic lens to circumvent the highly scattering scleral tissue. The resulting high-resolution images allowed the detailed structures in the trabecular meshwork (TM) to be observed. Multimodal imaging by two-photon autofluorescence and second harmonic generation allowed visualization of different features in the TM without labels and without disruption of the TM or surrounding tissues. MPM gonioscopy is a promising noninvasive imaging tool for high-resolution studies of the AOS, and research continues to explore the potential for future clinical applications in humans.
authors.affiliation: Department of Ophthalmology, University of Colorado Denver, 12800 East 19th Avenue Mailstop 8311, Aurora, Colorado 80045, USA.
authors.forename: Omid
authors.initials: O
authors.lastname: Masihzadeh
authors.forename: David A
authors.initials: DA
authors.lastname: Ammar
authors.forename: Malik Y
authors.initials: MY
authors.lastname: Kahook
authors.forename: Emily A
authors.initials: EA
authors.lastname: Gibson
authors.forename: Tim C
authors.initials: TC
authors.lastname: Lei
mesh_terms: D000818:Animals; D006068:Gonioscopy / Q000379:methods*; D006651:Histocytochemistry; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D036641:Microscopy, Fluorescence, Multiphoton / Q000379:methods*; D061848:Optical Imaging; D013552:Swine; D014129:Trabecular Meshwork / Q000033:anatomy & histology*