Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pseudoexfoliation syndrome is an ocular manifestation of a systemic elastosis. Exact etiology of this condition remains unknown. The basic pathogenetic concept of PEX is a pathological process of the extracellular matrix, characterized by the excessive production of an abnormal extracellular material which aggregates and accumulates and is not degraded in vivo. This material is produced primarily by the non pigmented epithelium of the ciliary body, the posterior iris pigment epithelium, and the preequatorial lens epithelium, while the corneal endothelium, trabecular cells, and vascular endothelia and smooth muscle cells of the iris have also been implicated. PEX material has a complex glycoprotein/proteoglycan, composition containing glycosaminoglycans (heparan sulfate, chondroitin sulfate, dermatan sulfate, hyaluronic acid). The prevailing presence of elastic fiber epitopes, mainly elastic microfibrillar components (elastin, vitronectin, amyloid P, fibrillin-1, LTBP-1), has led to the current theory explaining PEX as a type of elastosis, affecting especially elastic microfibrils. Ocular deposition of pseudoexfoliation material can lead to many complications in intraocular surgery like increased risk of zonular dehiscence, capsular rupture, vitreous loss during cataract extraction. Special attention is required before, during and after surgery.
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PMID:[Pseudoexfoliation syndrome--etiopatogenesis and clinical course]. 1688 48

Exfoliation syndrome (XFS) is an age-related, generalized disorder of the extracellular matrix characterized by the production and progressive accumulation of a fibrillar extracellular material in many ocular tissues and is the most common identifiable cause of open-angle glaucoma worldwide. XFS plays an etiologic role in open-angle glaucoma, angle-closure glaucoma, cataract, and retinal vein occlusion. It is accompanied by an increase in serious complications at the time of cataract extraction, such as zonular dialysis, capsular rupture, and vitreous loss. It is associated systemically with an increasing number of vascular disorders, hearing loss, and Alzheimer's disease. XFS appears to be a disease of elastic tissue microfibrils. The characteristic fibrils, composed of microfibrillar subunits surrounded by an amorphous matrix comprising various glycoconjugates, contain predominantly epitopes of elastic fibers, such as elastin, tropoelastin, amyloid P, vitronectin, and components of elastic microfibrils, such as fibrillin-1, fibulin-2, vitronectin, microfibril-associated glycoprotein (MAGP-1), and latent TGF-beta binding proteins (LTBP-1 and LTBP-2), the proteoglycans syndecan and versican, the extracellular chaperone clusterin, the cross-linking enzyme lysyl oxidase, and other proteins. A recent milestone study showed that two common single nucleotide polymorphisms in the coding region of the lysyl oxidase-like 1 (LOXL1) gene located on chromosome 15 were specifically associated with XFS and XFG. LOXL1 is a member of the lysyl oxidase family of enzymes, which are essential for the formation, stabilization, maintenance, and remodeling of elastic fibers and prevent age-related loss of elasticity of tissues. LOXL1 protein is a major component of exfoliation deposits and appears to play a role in its accumulation and in concomitant elastotic processes in intra- and extraocular tissues of XFS patients. This discovery should open the way to new approaches and directions of therapy for this protein disorder.
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PMID:The management of exfoliative glaucoma. 1892 11