PMID- 15671280
OWN - NLM
STAT- MEDLINE
DCOM- 20050311
LR  - 20220330
IS  - 0146-0404 (Print)
IS  - 0146-0404 (Linking)
VI  - 46
IP  - 2
DP  - 2005 Feb
TI  - Viscoelastic material properties of the peripapillary sclera in normal and 
      early-glaucoma monkey eyes.
PG  - 540-6
AB  - PURPOSE: To test the hypothesis that changes in the viscoelastic material 
      properties of peripapillary sclera are present within monkey eyes at the onset of 
      early experimental glaucoma detected by confocal scanning laser tomography 
      (CSLT). METHODS: Short-term (3-9 weeks), moderate (< or =44 mm Hg) intraocular 
      pressure (IOP) elevation was induced in one eye of each of eight male monkeys by 
      lasering the trabecular meshwork. This procedure generated early experimental 
      glaucoma, defined as the onset of CSLT-detected optic nerve head (ONH) surface 
      change, in the treated eye. Scleral tensile specimens from the superior and 
      inferior quadrants of the eight early-glaucoma eyes were subjected to uniaxial 
      stress relaxation and tensile tests to failure and the results compared with 
      similar data obtained in a previous study of 12 normal (nonglaucomatous) eyes. 
      Linear viscoelastic theory was used to characterize viscoelastic material 
      property parameters for each specimen. Differences in each parameter due to 
      quadrant and treatment were assessed by analysis of variance (ANOVA). RESULTS: 
      Peripapillary sclera from the early-glaucoma eyes exhibited an equilibrium 
      modulus (7.46 +/- 1.58 MPa) that was significantly greater than that measured in 
      normal eyes (4.94 +/- 1.22 MPa; mean +/- 95% confidence interval, P < 0.01, 
      ANOVA). Quadrant differences were not significant for the viscoelastic parameters 
      within each treatment group. CONCLUSIONS: The long-term viscoelastic material 
      properties of monkey peripapillary sclera are altered by exposure to moderate, 
      short-term, chronic IOP elevations and these alterations are present at the onset 
      of CSLT-detected glaucomatous damage to the ONH. Damage to and/or remodeling of 
      the extracellular matrix of these tissues may underlie these changes in scleral 
      material properties.
FAU - Downs, J Crawford
AU  - Downs JC
AD  - LSU Eye Center, Louisiana State University Health Sciences Center, New Orleans, 
      LA 70112, USA. jdowns@lsuhsc.edu
FAU - Suh, J-K Francis
AU  - Suh JK
FAU - Thomas, Kevin A
AU  - Thomas KA
FAU - Bellezza, Anthony J
AU  - Bellezza AJ
FAU - Hart, Richard T
AU  - Hart RT
FAU - Burgoyne, Claude F
AU  - Burgoyne CF
LA  - eng
GR  - R01 EY011610/EY/NEI NIH HHS/United States
GR  - P30EY002377/EY/NEI NIH HHS/United States
GR  - R01EY011610/EY/NEI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Invest Ophthalmol Vis Sci
JT  - Investigative ophthalmology & visual science
JID - 7703701
SB  - IM
MH  - Animals
MH  - Disease Models, Animal
MH  - Elastic Tissue/*physiology
MH  - Elasticity
MH  - Glaucoma/*physiopathology
MH  - Intraocular Pressure
MH  - Lasers
MH  - Macaca fascicularis
MH  - Macaca mulatta
MH  - Male
MH  - Ocular Hypertension/physiopathology
MH  - *Ocular Physiological Phenomena
MH  - Optic Disk/*physiopathology
MH  - Optic Nerve Diseases/*physiopathology
MH  - Sclera/*physiology
MH  - Tomography
MH  - Trabecular Meshwork/surgery
MH  - Viscosity
EDAT- 2005/01/27 09:00
MHDA- 2005/03/12 09:00
CRDT- 2005/01/27 09:00
PHST- 2005/01/27 09:00 [pubmed]
PHST- 2005/03/12 09:00 [medline]
PHST- 2005/01/27 09:00 [entrez]
AID - 46/2/540 [pii]
AID - 10.1167/iovs.04-0114 [doi]
PST - ppublish
SO  - Invest Ophthalmol Vis Sci. 2005 Feb;46(2):540-6. doi: 10.1167/iovs.04-0114.