Circumferential tensile stiffness of glaucomatous trabecular meshwork.

Published online

Journal Article

PURPOSE: Our previous work indicated that a larger circumferential Young's modulus (E) of trabecular meshwork (TM) correlated with a higher outflow facility (C) in normal human donor eyes. The current study investigated the influence of glaucomatous TM stiffness and cellularity on C. METHODS: Eight left eyes from glaucomatous human donors were perfused within 48 hours post mortem. Values of C were determined at pressures of 10, 20, 30, and 40 mm Hg. The TM was then dissected and imaged with optical coherence tomography to determine its cross-sectional area. Uniaxial tensile stress was applied longitudinally to TM segments to determine stress-strain curves. E was calculated at zero strain, representing the circumferential stiffness of the TM at a relaxed state. Confocal images of DAPI-stained TM segments were used to determine cellularity after mechanical stretching. RESULTS: C (μL/min/mm Hg) of glaucomatous eyes was 0.18 ± 0.02 (mean ± SE) at 10 mm Hg and decreased to 0.11 ± 0.02 when the pressure was increased to 40 mm Hg. C measured at 30 and 40 mm Hg correlated with TM cellularity. E was 12.5 MPa and 1.4 (geometric mean and SE) and did not statistically correlate with postmortem time, age, C, or cellularity. CONCLUSIONS: Compared with data of normal eyes observed in a previous study, C in glaucomatous eyes was reduced significantly, and the amount of reduction increased with increasing the pressure. E of glaucomatous TM was approximately one-fifth that of normal TM. Prospective studies are needed to further investigate the influence of TM tensile stiffness on outflow regulation.

Full Text

Duke Authors

Cited Authors

  • Camras, LJ; Stamer, WD; Epstein, D; Gonzalez, P; Yuan, F

Published Date

  • February 10, 2014

Published In

Volume / Issue

  • 55 / 2

Start / End Page

  • 814 - 823

PubMed ID

  • 24408980

Electronic International Standard Serial Number (EISSN)

  • 1552-5783

Digital Object Identifier (DOI)

  • 10.1167/iovs.13-13091

Language

  • eng

Conference Location

  • United States