Immunohistochemical distribution of type VI collagen in normal and glaucomatous human trabecular meshwork

Abstract 

· Background: An abnormally increased presence of type VI collagen has been shown in the lamina cribrosa of patients with primary and secondary glaucoma. This study was undertaken to investigate the pattern of type VI collagen within the aqueous outflow structures of glaucoma patients. · Methods: Trabecular meshwork samples of eight normal donor eyes and trabeculectomy specimens of 21 patients with different types of glaucoma were processed for either cryo-sectioning or for paraffin embedding. Immunohistochemical staining was conducted by use of polyclonal rabbit antibodies against human collagen type VI. · Results: Immunoreactivity for type VI collagen was evident in the cores of all trabecular beams. The strongest staining was detected in the uveal region of the human trabecular meshwork. Immunohistochemical labelling for type VI collagen was not more pronounced in the aqueous outflow structures of glaucoma patients than in normal eyes. · Conclusion: Collagen type VI is a ubiquitous structural component of the extracellular matrix in the human trabecular meshwork. However, type VI collagen does not appear to be of greater importance for the increased trabecular outflow resistance in glaucoma patients than in normal eyes.