title: Aqueous outflow: segmental and distal flow.
abstract: The elevated intraocular pressure (IOP) of primary open-angle glaucoma is caused by impaired outflow of aqueous humor through the trabecular meshwork. Within the juxtacanalicular region, alterations of both extracellular matrix homeostasis and the cellular tone of trabecular meshwork endothelial and the inner wall of Schlemm canal cells affect outflow. Newer pharmacologic agents that target trabecular meshwork and Schlemm canal cell cytoskeleton lower IOP. Aqueous drainage occurs nonhomogenously with greater flow going through certain portions of the TM and less going through other portions-a concept known as segmental flow, which is theoretically the result of outflow being dependent on the presence of discrete pores within Schlemm canal. The limited long-term success of trabecular meshwork bypass surgeries implicates the potential impact of resistance in Schlemm canal itself and collector channels. Additionally, others have observed that outflow occurs preferentially near collector channels. These distal structures may be more important to aqueous outflow than previously believed.
  
  
  BACKGROUND
  Dr. Rhee is a consultant to Aerie Pharmaceuticals, Alcon Laboratories, Inc., Allegan, Inc., Aquesys, Inc., Glaukos Corp., Ivantis, Inc., Johnson & Johnson, Merck Sharp & Dohme Corp. and Santen, Inc., and has received research funding from Alcon Laboratories, Inc., Merck Sharp & Dohme Corp., and Ivantis, Inc. No other author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From Harvard-MIT Division of Health Sciences and Technology (Swaminathan), Harvard Medical School, Boston, Massachusetts, and the Department of Ophthalmology & Visual Sciences (Oh, Kang, Rhee), Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Swarup S
authors.initials: SS
authors.lastname: Swaminathan
authors.affiliation: From Harvard-MIT Division of Health Sciences and Technology (Swaminathan), Harvard Medical School, Boston, Massachusetts, and the Department of Ophthalmology & Visual Sciences (Oh, Kang, Rhee), Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Dong-Jin
authors.initials: DJ
authors.lastname: Oh
authors.affiliation: From Harvard-MIT Division of Health Sciences and Technology (Swaminathan), Harvard Medical School, Boston, Massachusetts, and the Department of Ophthalmology & Visual Sciences (Oh, Kang, Rhee), Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Min Hyung
authors.initials: MH
authors.lastname: Kang
authors.affiliation: From Harvard-MIT Division of Health Sciences and Technology (Swaminathan), Harvard Medical School, Boston, Massachusetts, and the Department of Ophthalmology & Visual Sciences (Oh, Kang, Rhee), Case Western Reserve University, Cleveland, Ohio, USA. Electronic address: dougrhee@aol.com.
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Rhee
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use; D001082:Aqueous Humor / Q000502:physiology*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D014129:Trabecular Meshwork / Q000187:drug effects / Q000378:metabolism
chemical_list: D000959:Antihypertensive Agents
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