Microstructural Crimp of the Lamina Cribrosa and Peripapillary Sclera Collagen Fibers.
Invest Ophthalmol Vis Sci
; 58(9): 3378-3388, 2017 07 01.
Article
em En
| MEDLINE
| ID: mdl-28687851
ABSTRACT
Purpose:
Although collagen microstructural crimp is a major determinant of ocular biomechanics, no direct measurements of optic nerve head (ONH) crimp have been reported. Our goal was to characterize the crimp period of the lamina cribrosa (LC) and peripapillary sclera (PPS) at low and normal IOPs.Methods:
ONHs from 11 sheep eyes were fixed at 10-, 5-, or 0-mm Hg IOP and crimp periods measured manually from coronal cryosections imaged with polarized light microscopy (PLM). Using linear mixed-effect models, we characterized the LC and PPS periods, and how they varied with distance from the scleral canal edge.Results:
A total of 17,374 manual collagen crimp period measurements were obtained with high repeatability (1.9 µm) and reproducibility (4.7 µm). The periods were smaller (P < 0.001) and less variable in the LC than in the PPS average (SD) of 13.8 (3.1) µm in the LC, and 31.0 (10.4) µm in the PPS. LC crimp period did not vary with distance from the scleral canal wall (P > 0.1). PPS period increased with the square root of the distance to the canal (P < 0.0001).Conclusions:
Small, uniform crimp periods within the sheep LC and immediately adjacent PPS may indicate that these tissues are setup to prevent large or heterogeneous deformations that insult the neural tissues within the canal. An increasing more variable period with distance from the canal provides a smooth transition of mechanical properties that minimizes stress and strain concentrations.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Disco Óptico
/
Esclera
/
Doenças do Nervo Óptico
/
Colágeno
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Invest Ophthalmol Vis Sci
Ano de publicação:
2017
Tipo de documento:
Article