Document Detail

A trabecular bypass flow hypothesis.
MedLine Citation:
PMID:  15650609     Owner:  NLM     Status:  MEDLINE    
PURPOSE: To introduce a hypothesis that theorizes the effect of a trabecular bypass, a channel created through the trabecular meshwork, on the facility of outflow and the intraocular pressure (IOP). METHODS: Equations that govern the pressure and circumferential flow in Schlemm's canal are established, based on the linear relationships between pressure drop and flow, the balance of flows in the canal, and a uniform leaking structure of collector channels. Two types of bypasses permitting either unidirectional or bidirectional flow are incorporated through boundary conditions to solve the equations and to derive the facility of outflow and the reduced IOP. RESULTS: In normal healthy eyes, the facility of outflow increases by 13% and 26% in the presence of a unidirectional and bidirectional bypass, respectively. The circumferential flow is significant only in the immediate quadrant to the bypass. The elevated IOP due to the abnormally high resistance in trabecular meshwork in open angle glaucoma is substantially reduced with a single bypass. Mean physiological level of IOP is attained if the bidirectional bypass is placed; slightly higher IOP is attained if a unidirectional bypass is placed. In either case, the higher the baseline IOP, the greater the reduction. The effectiveness of the bypass on IOP reduction is related to the resistances in the canal and the collector channels. Multiple bypasses can be used to further reduce the IOP. CONCLUSION: It is theoretically demonstrated that a single patent trabecular bypass can enhance the facility of outflow and reduce the IOP to physiological levels.
Jianbo Zhou; Gregory T Smedley
Related Documents :
20179619 - Efficacy and mechanisms of intraocular pressure reduction with latanoprost and timolol ...
2630329 - The visual field in chronic simple glaucoma and ocular hypertension; its character, pro...
9626919 - Interaction between timolol eyedrops and oral nicardipine or oral diltiazem in healthy ...
11225139 - Intraocular pressure changes and mountaineering--preliminary observations and possible ...
9304439 - Clinical evaluation of a new formula of timolol maleate (wp-934 ophthalmic solution). w...
10396379 - Limited argon laser peripheral iridoplasty as immediate treatment for an acute attack o...
15785009 - White-coat hypertension contributes to the presence of carotid arteriosclerosis.
3177189 - The influence of daily activity on ambulatory blood pressure.
1447109 - Factors affecting blood pressure during heavy weight lifting and static contractions.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of glaucoma     Volume:  14     ISSN:  1057-0829     ISO Abbreviation:  J. Glaucoma     Publication Date:  2005 Feb 
Date Detail:
Created Date:  2005-01-14     Completed Date:  2005-03-14     Revised Date:  2006-11-03    
Medline Journal Info:
Nlm Unique ID:  9300903     Medline TA:  J Glaucoma     Country:  United States    
Other Details:
Languages:  eng     Pagination:  74-83     Citation Subset:  IM    
Research & Development, Glaukos Corporation, Laguna Hills, California 92653, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Aqueous Humor / secretion*
Glaucoma / metabolism,  physiopathology
Intraocular Pressure / physiology*
Models, Biological
Trabecular Meshwork / physiology*

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

Previous Document:  Effects of travoprost on aqueous humor dynamics in monkeys.
Next Document:  Complexity of medication use in the Veterans Affairs healthcare system: Part I: Outpatient use in re...