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Aqueous Humor Outflow

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Ocular Rigidity, Biomechanics and Hydrodynamics of the Eye

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Abstract

Aqueous humor outflow (AHO) is important for supporting normal eye physiology and vision. Altered AHO occurs in glaucoma because increased AHO resistance leads to increased intraocular pressure (IOP). This increased resistance occurs at the trabecular meshwork (TM) and distal to the TM. Soluble factors such as transforming growth factor beta (TGF-β) have been implicated in this process. Numerous tools are available to structurally or functionally study AHO that are either static or real-time in nature. These methods have been instrumental to better understanding normal AHO and unveiling the pathophysiology of diseased AHO in glaucoma.

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References

  1. Brubaker RF. Goldmann’s equation and clinical measures of aqueous dynamics. Exp Eye Res. 2004;78(3):633–7.

    Article  CAS  PubMed  Google Scholar 

  2. Goel M, Picciani RG, Lee RK, Bhattacharya SK. Aqueous humor dynamics: a review. Open Ophthalmol J. 2010;4:52–9.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Civan MM, Macknight AD. The ins and outs of aqueous humour secretion. Exp Eye Res. 2004;78(3):625–31.

    Article  CAS  PubMed  Google Scholar 

  4. Ruskell GL. An ocular parasympathetic nerve pathway of facial nerve origin and its influence on intraocular pressure. Exp Eye Res. 1970;10(2):319–30.

    Article  CAS  PubMed  Google Scholar 

  5. Phelps CD, Thompson HS, Ossoinig KC. The diagnosis and prognosis of atypical carotid-cavernous fistula (red-eyed shunt syndrome). Am J Ophthalmol. 1982;93(4):423–36.

    Article  CAS  PubMed  Google Scholar 

  6. Johnson M, McLaren JW, Overby DR. Unconventional aqueous humor outflow: a review. Exp Eye Res. 2017;158:94–111.

    Article  CAS  PubMed  Google Scholar 

  7. S HA, Structure NWR. Mechanism of uveoscleral outflow. In: Francis BA, Sarkisian SR, Tan JC, editors. Minimally invasive glaucoma surgery. New York: Thieme; 2017.

    Google Scholar 

  8. Yucel YH, Johnston MG, Ly T, et al. Identification of lymphatics in the ciliary body of the human eye: a novel “uveolymphatic” outflow pathway. Exp Eye Res. 2009;89(5):810–9.

    Article  PubMed  CAS  Google Scholar 

  9. Toris CB, Yablonski ME, Wang YL, Camras CB. Aqueous humor dynamics in the aging human eye. Am J Ophthalmol. 1999;127(4):407–12.

    Article  CAS  PubMed  Google Scholar 

  10. Bill A, Phillips CI. Uveoscleral drainage of aqueous humour in human eyes. Exp Eye Res. 1971;12(3):275–81.

    Article  CAS  PubMed  Google Scholar 

  11. Bill A. Conventional and uveo-scleral drainage of aqueous humour in the cynomolgus monkey (Macaca irus) at normal and high intraocular pressures. Exp Eye Res. 1966;5(1):45–54.

    Article  CAS  PubMed  Google Scholar 

  12. Grant WM. Experimental aqueous perfusion in enucleated human eyes. Arch Ophthalmol. 1963;69:783–801.

    Article  CAS  PubMed  Google Scholar 

  13. Johnson M. What controls aqueous humour outflow resistance? Exp Eye Res. 2006;82(4):545–57.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Vranka JA, Staverosky JA, Reddy AP, et al. Biomechanical rigidity and quantitative proteomics analysis of segmental regions of the trabecular meshwork at physiologic and elevated pressures. Invest Ophthalmol Vis Sci. 2018;59(1):246–59.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Braakman ST, Read AT, Chan DW, et al. Colocalization of outflow segmentation and pores along the inner wall of Schlemm’s canal. Exp Eye Res. 2015;130:87–96.

    Article  CAS  PubMed  Google Scholar 

  16. Huang AS, Mohindroo C, Weinreb RN. Aqueous humor outflow structure and function imaging at the bench and bedside: a review. J Clin Exp Ophthalmol. 2016;7(4)

    Google Scholar 

  17. Tandon A, Tovey JC, Sharma A, et al. Role of transforming growth factor Beta in corneal function, biology and pathology. Curr Mol Med. 2010;10(6):565–78.

    CAS  PubMed  PubMed Central  Google Scholar 

  18. Tripathi RC, Li J, Chan WF, Tripathi BJ. Aqueous humor in glaucomatous eyes contains an increased level of TGF-beta 2. Exp Eye Res. 1994;59(6):723–7.

    Article  CAS  PubMed  Google Scholar 

  19. Tamm ER, Fuchshofer R. What increases outflow resistance in primary open-angle glaucoma? Surv Ophthalmol. 2007;52(Suppl 2):S101–4.

    Article  PubMed  Google Scholar 

  20. Ochiai Y, Ochiai H. Higher concentration of transforming growth factor-beta in aqueous humor of glaucomatous eyes and diabetic eyes. Jpn J Ophthalmol. 2002;46(3):249–53.

    Article  CAS  PubMed  Google Scholar 

  21. Inatani M, Tanihara H, Katsuta H, et al. Transforming growth factor-beta 2 levels in aqueous humor of glaucomatous eyes. Graefes Arch Clin Exp Ophthalmol. 2001;239(2):109–13.

    Article  CAS  PubMed  Google Scholar 

  22. Quigley HA. The contribution of the sclera and lamina cribrosa to the pathogenesis of glaucoma: diagnostic and treatment implications. Prog Brain Res. 2015;220:59–86.

    Article  PubMed  Google Scholar 

  23. Huang AS, Penteado RC, Papoyan V, Voskanyan L, Weinreb RN. Aqueous angiographic outflow improvement after trabecular microbypass in glaucoma patients. Ophthalmol Glaucoma. 2019;2(1):11–21.

    Google Scholar 

  24. Dvorak-Theobald G, Kirk HQ. Aqueous pathways in some cases of glaucoma. Am J Ophthalmol. 1956;41(1):11–21.

    Article  CAS  PubMed  Google Scholar 

  25. Battista SA, Lu Z, Hofmann S, et al. Reduction of the available area for aqueous humor outflow and increase in meshwork herniations into collector channels following acute IOP elevation in bovine eyes. Invest Ophthalmol Vis Sci. 2008;49(12):5346–52.

    Article  PubMed  Google Scholar 

  26. Bentley MD, Hann CR, Fautsch MP. Anatomical variation of human collector channel orifices. Invest Ophthalmol Vis Sci. 2016;57(3):1153–9.

    Article  PubMed  PubMed Central  Google Scholar 

  27. Ashton N. Anatomical study of Schlemm’s canal and aqueous veins by means of neoprene casts. Part I. Aqueous veins. Br J Ophthalmol. 1951;35(5):291–303.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Van Buskirk EM. The canine eye: the vessels of aqueous drainage. Invest Ophthalmol Vis Sci. 1979;18(3):223–30.

    PubMed  Google Scholar 

  29. Hann CR, Bentley MD, Vercnocke A, et al. Imaging the aqueous humor outflow pathway in human eyes by three-dimensional micro-computed tomography (3D micro-CT). Exp Eye Res. 2011;92(2):104–11.

    Article  CAS  PubMed  Google Scholar 

  30. Chen RI, Barbosa DT, Hsu CH, et al. Ethnic differences in trabecular meshwork height by optical coherence tomography. JAMA Ophthalmol. 2015;133(4):437–41.

    Article  PubMed  Google Scholar 

  31. Gold ME, Kansara S, Nagi KS, et al. Age-related changes in trabecular meshwork imaging. Biomed Res Int. 2013;2013:295204.

    Article  PubMed  PubMed Central  Google Scholar 

  32. Hariri S, Johnstone M, Jiang Y, et al. Platform to investigate aqueous outflow system structure and pressure-dependent motion using high-resolution spectral domain optical coherence tomography. J Biomed Opt. 2014;19(10):106013.

    Article  PubMed  PubMed Central  Google Scholar 

  33. Li P, Shen TT, Johnstone M, Wang RK. Pulsatile motion of the trabecular meshwork in healthy human subjects quantified by phase-sensitive optical coherence tomography. Biomed Opt Express. 2013;4(10):2051–65.

    Article  PubMed  PubMed Central  Google Scholar 

  34. Kagemann L, Wollstein G, Ishikawa H, et al. Visualization of the conventional outflow pathway in the living human eye. Ophthalmology. 2012;119(8):1563–8.

    Article  PubMed  Google Scholar 

  35. Kagemann L, Wollstein G, Ishikawa H, et al. Identification and assessment of Schlemm’s canal by spectral-domain optical coherence tomography. Invest Ophthalmol Vis Sci. 2010;51(8):4054–9.

    Article  PubMed  PubMed Central  Google Scholar 

  36. Huang AS, Belghith A, Dastiridou A, et al. Automated circumferential construction of first-order aqueous humor outflow pathways using spectral-domain optical coherence tomography. J Biomed Opt. 2017;22(6):66010.

    Article  PubMed  Google Scholar 

  37. Li G, Farsiu S, Chiu SJ, et al. Pilocarpine-induced dilation of Schlemm’s canal and prevention of lumen collapse at elevated intraocular pressures in living mice visualized by OCT. Invest Ophthalmol Vis Sci. 2014;55(6):3737–46.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Li G, Mukherjee D, Navarro I, et al. Visualization of conventional outflow tissue responses to netarsudil in living mouse eyes. Eur J Pharmacol. 2016;787:20–31.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Skaat A, Rosman MS, Chien JL, et al. Microarchitecture of Schlemm Canal before and after selective laser trabeculoplasty in enhanced depth imaging optical coherence tomography. J Glaucoma. 2017;26(4):361–6.

    Article  PubMed  Google Scholar 

  40. Kagemann L, Wang B, Wollstein G, et al. IOP elevation reduces Schlemm’s canal cross-sectional area. Invest Ophthalmol Vis Sci. 2014;55(3):1805–9.

    Article  PubMed  PubMed Central  Google Scholar 

  41. Huang AS, Kim LA, Fawzi AA. Clinical characteristics of a large choroideremia pedigree carrying a novel CHM mutation. Arch Ophthalmol. 2012;130(9):1184–9.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Sabanay I, Gabelt BT, Tian B, et al. H-7 effects on the structure and fluid conductance of monkey trabecular meshwork. Arch Ophthalmol. 2000;118(7):955–62.

    CAS  PubMed  Google Scholar 

  43. Swaminathan SS, Oh DJ, Kang MH, et al. Secreted protein acidic and rich in cysteine (SPARC)-null mice exhibit more uniform outflow. Invest Ophthalmol Vis Sci. 2013;54(3):2035–47.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  44. Keller KE, Bradley JM, Vranka JA, Acott TS. Segmental versican expression in the trabecular meshwork and involvement in outflow facility. Invest Ophthalmol Vis Sci. 2011;52(8):5049–57.

    Article  PubMed  PubMed Central  Google Scholar 

  45. Vranka JA, Bradley JM, Yang YF, et al. Mapping molecular differences and extracellular matrix gene expression in segmental outflow pathways of the human ocular trabecular meshwork. PLoS One. 2015;10(3):e0122483.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  46. Fellman RL, Grover DS. Episcleral venous fluid wave: intraoperative evidence for patency of the conventional outflow system. J Glaucoma. 2014;23(6):347–50.

    Article  PubMed  Google Scholar 

  47. Fellman RL, Feuer WJ, Grover DS. Episcleral venous fluid wave correlates with trabectome outcomes: intraoperative evaluation of the trabecular outflow pathway. Ophthalmology. 2015;122(12):2385–91.e1.

    Article  PubMed  Google Scholar 

  48. Grieshaber MC. Ab externo Schlemm’s canal surgery: viscocanalostomy and canaloplasty. Dev Ophthalmol. 2012;50:109–24.

    Article  PubMed  Google Scholar 

  49. Zeppa L, Ambrosone L, Guerra G, et al. Using canalography to visualize the in vivo aqueous humor outflow conventional pathway in humans. JAMA Ophthalmol. 2014;132(11):1281.

    Article  PubMed  Google Scholar 

  50. Grieshaber MC, Pienaar A, Olivier J, Stegmann R. Clinical evaluation of the aqueous outflow system in primary open-angle glaucoma for canaloplasty. Invest Ophthalmol Vis Sci. 2010;51(3):1498–504.

    Article  PubMed  Google Scholar 

  51. Huang AS, Francis BA, Weinreb RN. Structural and functional imaging of aqueous humour outflow: a review. Clin Exp Ophthalmol. 2018;46(2):158–68.

    Article  PubMed  Google Scholar 

  52. Saraswathy S, Tan JC, Yu F, et al. Aqueous angiography: real-time and physiologic aqueous humor outflow imaging. PLoS One. 2016;11(1):e0147176.

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  53. Huang AS, Saraswathy S, Dastiridou A, et al. Aqueous angiography with fluorescein and indocyanine green in bovine eyes. Transl Vis Sci Technol. 2016;5(6):5.

    Article  PubMed  PubMed Central  Google Scholar 

  54. Snyder KC, Oikawa K, Williams J, Kiland JA, Gehrke S, Teixeira LBC, Huang AS, McLellan GJ. Imaging distal aqueous outflow pathways in a spontaneous model of congenital glaucoma. Transl Vis Sci Technol. 2019;8(5):22.

    Google Scholar 

  55. Huang AS, Saraswathy S, Dastiridou A, et al. Aqueous angiography-mediated guidance of trabecular bypass improves angiographic outflow in human enucleated eyes. Invest Ophthalmol Vis Sci. 2016;57(11):4558–65.

    Article  PubMed  PubMed Central  Google Scholar 

  56. Keane PA, Sadda SR. Imaging chorioretinal vascular disease. Eye (Lond). 2010;24(3):422–7.

    Article  CAS  Google Scholar 

  57. Saraswathy S, Bogarin T, Barron E, Francis BA, Tan JCH, Weinreb RN, Huang AS. Segmental differences found in aqueous angiographic-determined high – and low-flow regions of human trabecular meshwork. Exp Eye Res. 2020;196:108064.

    Google Scholar 

  58. Huang AS, Li M, Yang D, et al. Aqueous angiography in living nonhuman primates shows segmental, pulsatile, and dynamic angiographic aqueous humor outflow. Ophthalmology. 2017;124(6):793–803.

    Article  PubMed  Google Scholar 

  59. Huang AS, Camp A, Xu BY, et al. Aqueous angiography: aqueous humor outflow imaging in live human subjects. Ophthalmology. 2017;124(8):1249–51.

    Article  PubMed  Google Scholar 

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Acknowledgements

Funding for this work came from National Institutes of Health, Bethesda, MD (R01EY030501 [ASH]); Research to Prevent Blindness Career Development Award 2016 [ASH]; and an unrestricted grant from Research to Prevent Blindness (New York, NY).

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Authors and Affiliations

  1. Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA

    Goichi Akiyama, Thania Bogarin & Alex S. Huang

  2. Doheny Eye Institute, Los Angeles, CA, USA

    Sindhu Saraswathy & Alex S. Huang

Authors
  1. Goichi Akiyama
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  2. Thania Bogarin
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  3. Sindhu Saraswathy
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  4. Alex S. Huang
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Corresponding author

Correspondence to Alex S. Huang .

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Editors and Affiliations

  1. Department of Ophthalmology, University of Crete, Heraklion, Crete, Greece

    Ioannis Pallikaris

  2. Department of Ophthalmology, University of Crete, Heraklion, Crete, Greece

    Miltiadis K. Tsilimbaris

  3. 2nd Ophthalmology Department, Aristotle University of Thessaloniki, Thessaloniki, Greece

    Anna I. Dastiridou

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Akiyama, G., Bogarin, T., Saraswathy, S., Huang, A.S. (2021). Aqueous Humor Outflow. In: Pallikaris, I., Tsilimbaris, M.K., Dastiridou, A.I. (eds) Ocular Rigidity, Biomechanics and Hydrodynamics of the Eye. Springer, Cham. https://doi.org/10.1007/978-3-030-64422-2_11

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  • DOI: https://doi.org/10.1007/978-3-030-64422-2_11

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