Document Detail


Mechanism of exercise-induced ocular hypotension.
MedLine Citation:
PMID:  10102302     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: Although acute dynamic exercise reduces intraocular pressure (IOP), the factors that provoke this response remain ill-defined. To determine whether changes in colloid osmotic pressure (COP) cause the IOP changes during exercise, standardized exercise was performed after dehydration and hydration with isosmotic fluid. METHODS: Progressive cycle ergometer exercise to volitional exhaustion was performed after 4 hours' dehydration, and after hydration with 946 ml isosmotic liquid (345 mOsM). In each experiment, venous blood taken before and immediately after exercise was analyzed for hematocrit, plasma protein concentration, total plasma osmolality, and plasma COP. RESULTS: Exercise in both experiments significantly reduced IOP and elevated COP (each P < 0.01). Dehydration, compared with hydration, also significantly reduced IOP and elevated COP, when measured before and after exercise (P < 0.05). The correlation of mean IOP with mean COP, over the entire range created by varying exercise and hydration statuses, was statistically significant (r = -0.99; P < 0.001). In contrast, other indexes of hydration status, including hematocrit, total plasma osmolality, and plasma protein concentration, failed to change as IOP changed and failed to correlate with IOP, on either a group or individual basis, in conditions of varying levels of exercise and hydration. CONCLUSIONS: Acute dynamic exercise and isosmotic fluid ingestion each seem to change IOP through changes in COP.
Authors:
B Martin; A Harris; T Hammel; V Malinovsky
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Investigative ophthalmology & visual science     Volume:  40     ISSN:  0146-0404     ISO Abbreviation:  Invest. Ophthalmol. Vis. Sci.     Publication Date:  1999 Apr 
Date Detail:
Created Date:  1999-04-02     Completed Date:  1999-04-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7703701     Medline TA:  Invest Ophthalmol Vis Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1011-5     Citation Subset:  IM    
Affiliation:
Medical Sciences Program, Indiana University School of Medicine, Bloomington, USA.
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MeSH Terms
Descriptor/Qualifier:
Blood Proteins / analysis
Body Water / metabolism
Ergometry
Exercise*
Hematocrit
Humans
Intraocular Pressure / physiology*
Ocular Hypertension / blood,  etiology*,  physiopathology*
Osmolar Concentration
Osmotic Pressure
Water-Electrolyte Imbalance / physiopathology
Chemical
Reg. No./Substance:
0/Blood Proteins

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


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