Glaucoma is the leading cause of irreversible blindness in the United States and the world. Its mechanisms of action are not fully understood but the end result is a progressive loss of retinal ganglion cells, which are the cells that communicate visual information to the brain. To learn why retinal ganglion cells are selectively targeted, researchers use animal models in which the internal pressure of the eye is raised experimentally since ocular hypertension is a common symptom of the disease. Several models have gained widespread use over recent decades, producing an explosion of insights into glaucoma etiology and pathophysiology. Continued progress is hampered though by issues which plague current methods of pressure elevation on multiple fronts. Most significant of these are the efforts spent treating animals that fail to develop ocular hypertension, measuring intraocular pressure by hand on a frequent basis, and pooling data to overcome variability in the amount and time course of pressure changes. This project puts forth an innovative system of glaucoma induction and regulation that is ground-breaking in its promise of near-zero failure rate, near-constant pressure changes, and near-effortless pressure reading. The system has the potential to not only accelerate research advances from animal glaucoma models, but also to arm clinicians with a new tool for arresting progression of the disease in humans for whom existing methods have been exhausted.
The specific aims of the project are: i) to implement a tethered and head- mounted version of the proposed system for use on rats and ii) to evaluate the long-term performance of the system with intraocular pressure measurements, electrophysiological recordings, and ocular imaging on live rats. The overall goal is to apply the research tool to the rat glaucoma model in order to address questions that are otherwise difficult to answer experimentally, like how does the outflow capacity of the living eye and the physiological properties of its optic nerve cells change as glaucoma progresses. In so doing the project will help speed progress in the fight against this debilitating disease.

Public Health Relevance

Glaucoma is an ocular disease that damages the output neurons of the eye, resulting in visual impairments and eventually blindness. It is often associated with eye pressures that are abnormally high, and this project puts forward an innovative method of inducing and monitoring pressure changes that stands to revolutionize how the causes and effects of the disease are investigated in animal models and perhaps how the disease is treated in humans.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21EY023376-02
Application #
8829860
Study Section
Bioengineering of Neuroscience, Vision and Low Vision Technologies Study Section (BNVT)
Program Officer
Chin, Hemin R
Project Start
2014-04-01
Project End
2017-03-31
Budget Start
2015-04-01
Budget End
2017-03-31
Support Year
2
Fiscal Year
2015
Total Cost
Indirect Cost
Name
University of South Florida
Department
Engineering (All Types)
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
069687242
City
Tampa
State
FL
Country
United States
Zip Code
33612
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Bello, Simon A; Passaglia, Christopher L (2017) A Wireless Pressure Sensor for Continuous Monitoring of Intraocular Pressure in Conscious Animals. Ann Biomed Eng 45:2592-2604
Bello, Simon A; Malavade, Sharad; Passaglia, Christopher L (2017) Development of a Smart Pump for Monitoring and Controlling Intraocular Pressure. Ann Biomed Eng 45:990-1002
Tang, Xiaolan; Tzekov, Radouil; Passaglia, Christopher L (2016) Retinal cross talk in the mammalian visual system. J Neurophysiol 115:3018-29