Document Detail


Mechanisms of rubbing-related corneal trauma in keratoconus.
MedLine Citation:
PMID:  19512912     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: Corneal scarring in keratoconus, which is observed prior to contact lens wear and in association with a chronic habit of abnormal rubbing, suggests a keratocyte change to a repair phenotype in response to rubbing trauma. METHODS: This review examines known and putative mechanisms for rubbing-related corneal trauma and cone formation. RESULTS: Responses to eye rubbing (and possible causal links) may include increased corneal temperature, epithelial thinning, increased concentrations of inflammatory mediators in the precorneal tears, abnormal enzyme activity, large intraocular pressure spikes, high hydrostatic tissue pressure, thixotropically reduced ground substance viscosity, temporary displacement of ground substance from the corneal apex, buckling and flexure of fibrils associated with waves of corneal indentation, biomechanically coupled curvature transfer to the cone apex, slippage between collagen fibrils at the cone apex, and changes to keratocytes due to mechanical trauma and/or high hydrostatic pressure, in addition to scar formation. Cone formation appears to depend on a loss of shear strength and may be a consequence of a reduction in ground substance viscosity and glue function, which could allow the cornea to bend and yield to intraocular pressure. CONCLUSIONS: For some forms of keratoconus, a reduction in shear strength and cone-forming deformation may be responses to rubbing trauma. Some of the mechanisms for corneal rubbing trauma may be relevant to post-laser-assisted in situ keratomileusis ectasia or complications following other types of corneal surgery. There appear to be indications for the control of chronic habits of abnormal rubbing.
Authors:
Charles W McMonnies
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Cornea     Volume:  28     ISSN:  1536-4798     ISO Abbreviation:  Cornea     Publication Date:  2009 Jul 
Date Detail:
Created Date:  2009-06-24     Completed Date:  2009-09-08     Revised Date:  2010-07-28    
Medline Journal Info:
Nlm Unique ID:  8216186     Medline TA:  Cornea     Country:  United States    
Other Details:
Languages:  eng     Pagination:  607-15     Citation Subset:  IM    
Affiliation:
From the School of Optometry and Vision Science, University of New South Wales, Kensington, Australia.
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MeSH Terms
Descriptor/Qualifier:
Animals
Cicatrix / etiology
Cornea / injuries*
Disease Progression
Eye*
Eye Injuries / complications,  etiology
Humans
Keratoconus / etiology*,  physiopathology*
Massage / adverse effects*
Comments/Corrections
Comment In:
Cornea. 2010 Feb;29(2):245   [PMID:  20098158 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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