title: [Unilateral or asymmetric PEX syndrome? An electron microscopy study].
abstract: BACKGROUND
  The pseudoexfoliation (PEX) syndrome which is characterized by the accumulation of an abnormal extracellular material in intra- and extraocular tissues, clinically strictly manifests both unilateral and bilateral. However, the generalized nature of this matrix process does not support unilateral ocular manifestation. The aim of this study, therefore, was a detailed histopathological analysis of the apparently not involved fellow eyes in so-called "unilateral" PEX syndrome.
  
  
  METHODS
  For transmission electron microscopy, 5 pairs of donor eyes with slitlamp-microscopic, macroscopic and light microscopic evidence of unilateral PEX syndrome and 6 normal control eyes were studied. For immunohistochemistry, light and electron microscopic antibodies against LTBP-1 and HNK-1, two well-known markers for PEX deposits, were used.
  
  
  RESULTS
  All apparently not involved contralateral eyes showed ultrastructural changes in the iris, in the ciliary body and in the trabecular meshwork. These changes include deposits of typical PEX fibrils on iris and ciliary epithelia as well as in the iris dilator muscle, microfibrillar precursors in the periphery of iris vessels, degenerative changes of the iris pigment epithelium and of the dilator muscle and an increased accumulation of extracellular matrix components around iris vessels, in the dilator muscle and in the juxta-canalicular connective tissue of the trabecular meshwork. In all contralateral and PEX eyes, but not in the control eyes, LTBP-1 and HNK-1 positive deposits could be identified in the periphery of iris vessels and in the dilator by light- and electron microscopic immunolabeling.
  
  
  CONCLUSIONS
  The observed alterations in contralateral eyes in so-called "unilateral" PEX syndrome support the concept that the PEX syndrome is a generalized, basically bilateral disease which may present in a clinically asymmetric manifestation. This should be considered in the clinical management of these patients.
authors.affiliation: Augenklinik mit Poliklinik der Friedrich-Alexander-Universität Erlangen-Nürnberg.
authors.forename: T
authors.initials: T
authors.lastname: Hammer
authors.forename: U
authors.initials: U
authors.lastname: Schlötzer-Schrehardt
authors.forename: A
authors.initials: A
authors.lastname: Jünemann
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D018959:CD57 Antigens / Q000276:immunology; D002352:Carrier Proteins / Q000276:immunology; D016022:Case-Control Studies; D017889:Exfoliation Syndrome / Q000473:pathology*; D005123:Eye / Q000473:pathology*; D007839:Functional Laterality; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D007498:Iris / Q000473:pathology; D053779:Latent TGF-beta Binding Proteins; D008854:Microscopy, Electron; D016212:Transforming Growth Factor beta / Q000276:immunology
chemical_list: D015415:Biomarkers; D018959:CD57 Antigens; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C509032:LTBP1 protein, human; D053779:Latent TGF-beta Binding Proteins; D016212:Transforming Growth Factor beta