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Aqueous Humor and the Dynamics of Its Flow: Mechanisms and Routes of Aqueous Humor Drainage

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Albert and Jakobiec's Principles and Practice of Ophthalmology

Abstract

This chapter provides an updated review on anatomy and physiology of aqueous production and outflow geared toward the clinician. The composition and flow pathways for aqueous humor are described, followed by a detailed discussion of the clinical anatomy, histology, and ultrastructure of the ciliary body, including the anatomical basis for the blood-aqueous barrier. The principal pathways employed for movement of ions and fluid from the ciliary body microvasculature to secretion of aqueous humor by the ciliary epithelial layers are provided in detail. Emphasis is placed on pathways and mechanisms amenable to therapeutic intervention in glaucoma.

The clinical anatomy, histology, and ultrastructure of the aqueous outflow pathways are then described, with emphasis on correlating anatomical structure with features seen by gonioscopy. The anatomy of the conventional or trabecular outflow pathway and uveoscleral outflow pathway is detailed. The roles of ciliary muscle in regulation of the trabecular and uveoscleral outflow are presented, along with more recent discoveries including the funneling effect and the segmental nature of trabecular outflow. Emphasis is again placed on mechanisms and pathways exploited for reduction of intraocular pressure in the glaucomas. The chapter concludes with a concise discussion of current consensus on the location and generation of aqueous outflow resistance in the normal and glaucomatous eye.

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Acknowledgments

The original work of TFF reported in this chapter was supported by NEI EY-04567 and NEI EY-13825 and by National Glaucoma Research, a program of the BrightFocus Foundation.

The original work of MC reported in this chapter was supported in part by NEI EY-08343 and EY-13624.

The original work of HG reported in this chapter was supported in part by NEI, EY-09699, EY022634, the Massachusetts Lions Eye Research Fund, and National Glaucoma Research, a program of the BrightFocus Foundation.

Author information

Authors and Affiliations

  1. School of Optometry, MCP Health Sciences University, Worcester, MA, USA

    Thomas F. Freddo

  2. Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA

    Mortimer Civan

  3. Boston University School of Medicine, Boston, MA, USA

    Haiyan Gong

Authors
  1. Thomas F. Freddo
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  2. Mortimer Civan
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  3. Haiyan Gong
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Corresponding author

Correspondence to Haiyan Gong .

Editor information

Editors and Affiliations

  1. Casey Eye Institute, Oregon Health & Science, Portland, OR, USA

    Daniel M. Albert

  2. Department of Ophthalmology, Massachusetts Eye and Ear, Massachusetts General Hospital, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA

    Joan W. Miller

  3. Department of Ophthalmology, University of Illinois College of Medicine, University of Illinois at Chicago, Chicago, IL, USA

    Dimitri T. Azar

  4. Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA

    Lucy H. Young

Section Editor information

  1. New York Eye and Ear Infirmary of Mount Sinai, New York, USA

    James C. Tsai

  2. Department of Ophthalmology, Stanford University, Palo Alto, USA

    Yang Sun

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Freddo, T.F., Civan, M., Gong, H. (2022). Aqueous Humor and the Dynamics of Its Flow: Mechanisms and Routes of Aqueous Humor Drainage. In: Albert, D.M., Miller, J.W., Azar, D.T., Young, L.H. (eds) Albert and Jakobiec's Principles and Practice of Ophthalmology. Springer, Cham. https://doi.org/10.1007/978-3-030-42634-7_163

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  • DOI: https://doi.org/10.1007/978-3-030-42634-7_163

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  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-030-42633-0

  • Online ISBN: 978-3-030-42634-7

  • eBook Packages: MedicineReference Module Medicine

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