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.