Hydrodynamics of aqueous humor outflow

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness resulting from elevated intraocular pressure caused by a pathologic increase in the resistance to aqueous humor outflow from the eye. Currently, the physiological and ultrastructural bases for the generation of aqueous humor outflow resistance remain unclear in both the normal and glaucomatous eye, although experimental evidence suggests that the extracellular matrix within the juxtacanalicular connective tissue (JCT) is the principle resistive element. Johnson, Shapiro et al. (1992) have postulated that the resistance of the JCT is further increased by a hydrodynamic "funneling" interaction whereby the available area for aqueous flow through the JCT is reduced by the constraint that aqueous must cross the inner wall endothelium of Schlemm's canal through discrete pores. In this study, we focus on uncovering the role of the JCT in the generation of aqueous humor outflow resistance in the non-glaucomatous eye. Quick-freeze/deep-etch (QF/DE) electron microscopy was used to visualize the extracellular matrix within the JCT. A novel stereologic theory was developed to relate the two-dimensional void area and perimeter observed on a micrograph to the three-dimensional tissue porosity and specific surface, allowing the hydraulic resistance of an extracellular matrix to be estimated from a QF/DE micrograph. Extensive numerical studies were conducted to validate the predictions of the stereologic theory. To investigate the funneling effect,

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2002

Author dc:creator

• Overby, Darryl Ray, 1974-

Advisor dc:contributor.advisor

• Mark Johnson.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/89882

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/89882