June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
A mathematical model of aqueous humor dynamics and ocular pulse amplitude.
Author Affiliations & Notes
  • Anhtuan Hoang Nguyen
    Department of Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States
  • Jeffrey W Kiel
    Department of Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States
  • Footnotes
    Commercial Relationships   Anhtuan Nguyen, None; Jeffrey Kiel, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 1065. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Anhtuan Hoang Nguyen, Jeffrey W Kiel; A mathematical model of aqueous humor dynamics and ocular pulse amplitude.. Invest. Ophthalmol. Vis. Sci. 2017;58(8):1065.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : To depict steady state aqueous humor dynamics and the pulsatile nature of intraocular pressure (IOP) during physiological and non-physiological conditions utilizing a mathematical model. Studies have suggested that ocular pulse amplitude (OPA), which is defined as the difference between the maximum and minimum IOP, may play a role in glaucoma progression.

Methods : A mathematical model was developed in LabVIEW, a visual programming language (National Instruments, Austin, TX). The model establishes the relationships between ciliary and choroidal hemodynamics, passive and active process of aqueous production, aqueous outflow facility and the aqueous outflow via the trabecular and uveoscleral pathways, and the IOP. The pulsatility of the model is a polynomial function of heart rate and systemic blood pressure to simulate the arterial pulse. The model is consistent with current concepts of aqueous dynamics and has been validated by a number of in vivo studies.

Results : The model depicts the pulsatile nature of IOP at different outflow facilities (figure 1). IOP increases nonlinearly as outflow facility decreases. The model shows that as IOP increases the OPA increases linearly (figure 2). At an average IOP of 18 mmHg the OPA is 3.3 mmHg while at an average IOP of 49 mmHg the OPA is 9.2 mmHg.

Conclusions : The model accurately simulates the pulsatile nature of aqueous humor dynamics in accordance with clinical observations. The model is useful to study aqueous dynamics parameters that are difficult to measure in vivo.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Figure 1: The effect on intraocular pressure (IOP) at different outflow facilities (C, µL/min/mmHg).

Figure 1: The effect on intraocular pressure (IOP) at different outflow facilities (C, µL/min/mmHg).

 

Figure 2: The ocular pulse amplitude increases as the intraocular pressure increases.

Figure 2: The ocular pulse amplitude increases as the intraocular pressure increases.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×