Effects of Prolonged Eye Pressure Elevation on Visual Brain Changes

Kevin Chan, PhD
University of Pittsburgh (Pittsburgh, PA)
Year Awarded:
Grant Duration:
July 1, 2013 to June 30, 2015
Award Amount:
Grant Reference ID:
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Award Region:
US Northeastern

Co-principal Investigators

Joel Schuman, MD
New England Medical Center (Boston, MA)
Ian Conner, MD, PhD
University of Pittsburgh

Effects of Ocular Hypertension on Visual Brain Damage


Glaucoma is the second leading cause of blindness in the world. Although elevated eye pressure is a major risk factor, recent evidence suggested the involvement of the visual brain, apart from the eye, in the early degenerative mechanisms of glaucoma. Drs. Chan, Conner and Schuman’s goal is to develop new structural, metabolic, and functional magnetic resonance imaging (MRI, a machine that takes detailed images of the inside of the body) techniques for glaucoma. They will make whole-brain, non-invasive and repeated measurements over a period of time to evaluate the damage to the visual pathway and disease progression under different levels of chronic high eye pressure, and monitor for potential neuroprotection after treatment with a drug that lowers eye pressure. The development of novel methods for characterizing chronic glaucoma and neuroprotection in the visual system can potentially lead to more timely intervention and targeted treatments in reducing the burden of this disease.


Although elevated eye pressure is a major risk factor for glaucoma, recent evidence suggests the involvement of the visual brain, apart from the eye, in the early degenerative mechanisms of glaucoma. Drs. Chan, Conner and Schuman’s laboratory is testing the hypothesis that the degenerative events that occur in the visual pathways in the brain under chronic ocular hypertension can be detected and quantified using [1] microstructural, [2] metabolic and [3] functional MRI at a high magnetic field strength. In addition, they will investigate the neuroprotective effects of a commonly used ocular hypotensive drug on the changes to the visual pathways under elevated eye pressure.

When the study is complete, this project will offer, for the first time, an ability to measure non-invasive and comprehensive indicators for longitudinally assessing the structural, metabolic and functional effects on the visual system in glaucoma. In addition, the information provided will help to understand the very core of the processes that result in visual brain damage after different levels of prolonged elevation of eye pressure in glaucoma. This knowledge may lead to more targeted treatments and improved visual outcomes for reducing the burden of the disease.

Drs. Chan, Conner and Schuman expect that the proposed imaging approaches will greatly enhance the ability to detect and predict glaucoma progression in the visual system, and therefore allow for interventions at the earliest possible stage. Furthermore, the imaging techniques developed in this project could be used in the future to assess the beneficial effects of treatments for chronic glaucoma and other eye diseases that involve the brain. The team is excited to be involved in this research effort, and appreciates the BrightFocus donors’ support of their glaucoma neuroimaging work.

About the Researcher

Dr. Chan is an Assistant Professor of Ophthalmology and Bioengineering at the University of Pittsburgh. He completed his doctoral studies at The University of Hong Kong and was awarded the Li Ka Shing Prize for the best PhD thesis at the University. Dr. Chan is directing an MRI research program on structural, metabolic and functional imaging of the visual system in health and disease. His laboratory focuses on developing new methods of non-invasively imaging neurodegeneration, neurodevelopment, neuroplasticity and neuroregeneration in eye diseases and injuries to provide better strategies for vision preservation and restoration. In addition to his BrightFocus award, Dr. Chan is a Junior Fellow of the International Society for Magnetic Resonance in Medicine and was a 2009-2010 Fulbright Scholar. He is currently a Deputy Editor of the Journal of Magnetic Resonance Imaging.