Investigative Ophthalmology & Visual Science, Vol 36, 1750-1764, Copyright © 1995 by Association for Research in Vision and Ophthalmology

ARTICLES AND REPORTS

Trabecular meshwork in pseudoexfoliation syndrome with and without open- angle glaucoma. A morphometric, ultrastructural study

U Schlotzer-Schrehardt and GO Naumann
Department of Ophthalmology, University of Erlangen-Nurnberg, Germany.

PURPOSE. To test the hypothesis that glaucoma in eyes with pseudoexfoliation (PEX) syndrome results from blockage of the outflow channels by PEX material, melanin granules from the iris pigment epithelium, or both, and to determine the origin of intratrabecular PEX material. METHODS. Trabecular meshwork tissue was obtained from five surgically enucleated eyes with PEX glaucoma, ten autopsy eyes with PEX syndrome without evidence of glaucoma, and six age-matched control eyes. Morphometric methods were used to measure the percentage area occupied by open spaces, cells, plaque material, PEX material, and melanin granules on electron micrograph montages of the entire filtration area and the juxtacanalicular tissue (JCT) area. RESULTS. Independent of the presence of glaucoma, most PEX deposits were located in the JCT adjacent to the inner and outer walls of Schlemm's canal, as well as in the uveal meshwork. Although ultrastructural evidence indicates the local production of PEX fibers in the JCT by endothelial and connective tissue cells, PEX material in the uveal meshwork is derived partly from the aqueous humor. A significant correlation could be established between the presence of glaucoma and the amount of PEX material in both the filtration area and the JCT, the average thickness of the JCT, and the mean cross-sectional area of Schlemm's canal. No significant correlation existed, however, between glaucoma status and the concentration of melanin granules or plaque material, and the cellularity. CONCLUSION. In addition to a mechanical obstruction by PEX material of exotrabecular origin, the apparent production of PEX material by trabecular cells may be principally responsible for glaucoma development. Accumulation of locally produced PEX material in the JCT, followed by dysfunction of endothelial cells and disorganization of JCT and Schlemm's canal, appear to be causative factors in the development of a special type of secondary open-angle glaucoma in PEX syndrome.

This article has been cited by other articles:

				M. Ozaki, K. Y. C. Lee, E. N. Vithana, V. H. Yong, A. Thalamuthu, T. Mizoguchi, A. Venkatraman, and T. Aung Association of LOXL1 Gene Polymorphisms with Pseudoexfoliation in the Japanese Invest. Ophthalmol. Vis. Sci., September 1, 2008; 49(9): 3976 - 3980. [Abstract] [Full Text] [PDF]

				T. V. Johnson, S. Fan, C. B. Camras, and C. B. Toris Aqueous Humor Dynamics in Exfoliation Syndrome Arch Ophthalmol, July 1, 2008; 126(7): 914 - 920. [Abstract] [Full Text] [PDF]

				S. Chakrabarti, K. N. Rao, I. Kaur, R. S. Parikh, A. K. Mandal, G. Chandrasekhar, and R. Thomas The LOXL1 Gene Variations Are Not Associated with Primary Open-Angle and Primary Angle-Closure Glaucomas Invest. Ophthalmol. Vis. Sci., June 1, 2008; 49(6): 2343 - 2347. [Abstract] [Full Text] [PDF]

				G. H.-F. Yam, K. Gaplovska-Kysela, C. Zuber, and J. Roth Aggregated Myocilin Induces Russell Bodies and Causes Apoptosis: Implications for the Pathogenesis of Myocilin-Caused Primary Open-Angle Glaucoma Am. J. Pathol., January 1, 2007; 170(1): 100 - 109. [Abstract] [Full Text] [PDF]

				J. Gottanka, A. Kuhlmann, M. Scholz, D. H. Johnson, and E. Lutjen-Drecoll Pathophysiologic Changes in the Optic Nerves of Eyes with Primary Open Angle and Pseudoexfoliation Glaucoma Invest. Ophthalmol. Vis. Sci., November 1, 2005; 46(11): 4170 - 4181. [Abstract] [Full Text] [PDF]

				M. P. Fautsch, K. G. Howell, A. M. Vrabel, M. C. Charlesworth, D. C. Muddiman, and D. H. Johnson Primary Trabecular Meshwork Cells Incubated in Human Aqueous Humor Differ from Cells Incubated in Serum Supplements Invest. Ophthalmol. Vis. Sci., August 1, 2005; 46(8): 2848 - 2856. [Abstract] [Full Text] [PDF]

				U. Schlotzer-Schrehardt, J. Lommatzsch, M. Kuchle, A. G. P. Konstas, and G. O. H. Naumann Matrix Metalloproteinases and Their Inhibitors in Aqueous Humor of Patients with Pseudoexfoliation Syndrome/Glaucoma and Primary Open-Angle Glaucoma Invest. Ophthalmol. Vis. Sci., March 1, 2003; 44(3): 1117 - 1125. [Abstract] [Full Text] [PDF]

				P Hamard, F Valtot, P Sourdille, F Bourles-Dagonet, and C Baudouin Confocal microscopic examination of trabecular meshwork removed during ab externo trabeculectomy Br. J. Ophthalmol., September 1, 2002; 86(9): 1046 - 1052. [Abstract] [Full Text] [PDF]

				D. H. Johnson and Y. Matsumoto Schlemm's Canal Becomes Smaller After Successful Filtration Surgery Arch Ophthalmol, September 1, 2000; 118(9): 1251 - 1256. [Abstract] [Full Text] [PDF]