|
|
||||||||
1 From the Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri; 3 Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison; and 2 Departments of Immunology and Ophthalmology, Universidade Federal de Uberlandia, Uberlandia, Brazil.
PURPOSE. To determine whether abnormal elastin synthesis in the glaucomatous optic nerve head and lamina cribrosa is due to elevated intraocular pressure (IOP) or secondary to axonal injury, monkeys with elevated IOP and with optic nerve transection were compared .
METHODS. Unilateral, chronic elevated IOP was induced in 11 rhesus monkeys by laser scarification of the trabecular meshwork. IOP was monitored weekly and maintained within 25 to 45 mm Hg for 7 to 36 weeks. In 6 monkeys, unilateral, optic nerve transection was performed, and monkeys were killed after 4 weeks. Optic nerve damage was assessed by stereoscopic slit-lamp biomicroscopy and fundus photography and by confocal scanning laser ophthalmoscopy. The eyes were enucleated and processed for immunohistochemistry and in situ hybridization and for electron microscopic immunogold detection of elastin. Axonal loss was evaluated in cross sections of the optic nerve stained with phenylenediamine.
RESULTS. Compared with normal contralateral controls, the lamina cribrosa of eyes with elevated IOP exhibited markedly increased elastin and the presence of elastotic aggregates in the extracellular matrix and upregulation of elastin mRNA in the astrocytes. In transected eyes, elastin appeared as fine fibers in the lamina cribrosa, without elastotic aggregates, and without new synthesis or abnormal deposition of elastin. At the transected site, new synthesis of elastin was present in the pia mater but not in astrocytes in the glial scar.
CONCLUSIONS. This study demonstrates that abnormal elastin synthesis in experimental glaucomatous optic neuropathy in the monkey is specific to elevated IOP and not secondary to axonal loss. The mechanisms by which elevated IOP induces enhanced elastin synthesis in laminar astrocytes are unknown but differ from those involved in acute axonal injury such as transection, where inflammation and breakdown of the bloodnerve barrier occur.
This article has been cited by other articles:
![]() |
J. F Schmidt, O. A Agapova, P. Yang, P. L Kaufman, and M R. Hernandez Expression of ephrinB1 and its receptor in glaucomatous optic neuropathy Br. J. Ophthalmol., September 1, 2007; 91(9): 1219 - 1224. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. C. Johnson, L. Jia, W. O. Cepurna, T. A. Doser, and J. C. Morrison Global Changes in Optic Nerve Head Gene Expression after Exposure to Elevated Intraocular Pressure in a Rat Glaucoma Model Invest. Ophthalmol. Vis. Sci., July 1, 2007; 48(7): 3161 - 3177. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Urban, O. Agapova, V. Hucthagowder, P. Yang, B. C. Starcher, and M. R. Hernandez Population Differences in Elastin Maturation in Optic Nerve Head Tissue and Astrocytes Invest. Ophthalmol. Vis. Sci., July 1, 2007; 48(7): 3209 - 3215. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. K. Bhattacharya, J. S. Crabb, V. L. Bonilha, X. Gu, H. Takahara, and J. W. Crabb Proteomics implicates peptidyl arginine deiminase 2 and optic nerve citrullination in glaucoma pathogenesis. Invest. Ophthalmol. Vis. Sci., June 1, 2006; 47(6): 2508 - 2514. [Abstract] [Full Text] [PDF] |
||||
![]() |
L Guo, V Tsatourian, V Luong, A G Podolean, D A Jackson, F W Fitzke, and M F Cordeiro En face optical coherence tomography: a new method to analyse structural changes of the optic nerve head in rat glaucoma Br. J. Ophthalmol., September 1, 2005; 89(9): 1210 - 1216. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Spoerl, A. G. Boehm, and L. E. Pillunat The Influence of Various Substances on the Biomechanical Behavior of Lamina Cribrosa and Peripapillary Sclera Invest. Ophthalmol. Vis. Sci., April 1, 2005; 46(4): 1286 - 1290. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. Downs, J-K. F. Suh, K. A. Thomas, A. J. Bellezza, R. T. Hart, and C. F. Burgoyne Viscoelastic Material Properties of the Peripapillary Sclera in Normal and Early-Glaucoma Monkey Eyes Invest. Ophthalmol. Vis. Sci., February 1, 2005; 46(2): 540 - 546. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Wamsley, B. T. Gabelt, D. B. Dahl, G. L. Case, R. W. Sherwood, C. A. May, M. R. Hernandez, and P. L. Kaufman Vitreous Glutamate Concentration and Axon Loss in Monkeys With Experimental Glaucoma Arch Ophthalmol, January 1, 2005; 123(1): 64 - 70. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Ahmed, K. M. Brown, D. A. Stephan, J. C. Morrison, E. C. Johnson, and S. I. Tomarev Microarray Analysis of Changes in mRNA Levels in the Rat Retina after Experimental Elevation of Intraocular Pressure Invest. Ophthalmol. Vis. Sci., April 1, 2004; 45(4): 1247 - 1258. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. Levin, R. Ritch, J. E. Richards, and T. Borras Stem Cell Therapy for Ocular Disorders Arch Ophthalmol, April 1, 2004; 122(4): 621 - 627. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. C. Chauhan, T. L. LeVatte, C. A. Jollimore, P. K. Yu, H. A. Reitsamer, M. E. M. Kelly, D.-Y. Yu, F. Tremblay, and M. L. Archibald Model of Endothelin-1-Induced Chronic Optic Neuropathy in Rat Invest. Ophthalmol. Vis. Sci., January 1, 2004; 45(1): 144 - 152. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. D. Grozdanic, D. M. Betts, D. S. Sakaguchi, R. A. Allbaugh, Y. H. Kwon, and R. H. Kardon Laser-Induced Mouse Model of Chronic Ocular Hypertension Invest. Ophthalmol. Vis. Sci., October 1, 2003; 44(10): 4337 - 4346. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. C. Chauhan, J. Pan, M. L. Archibald, T. L. LeVatte, M. E. M. Kelly, and F. Tremblay Effect of Intraocular Pressure on Optic Disc Topography, Electroretinography, and Axonal Loss in a Chronic Pressure-Induced Rat Model of Optic Nerve Damage Invest. Ophthalmol. Vis. Sci., September 1, 2002; 43(9): 2969 - 2976. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |