Disruption of Inter-hemispheric Transfer in Early Glaucoma

Summary

Glaucoma is known as the “silent killer of vision” because a large proportion of people are not aware they have it until the late stages of the disease, and therefore it is very important to detect the disease early so these patients get help. It is also important to understand the disease in order to develop new lines of treatments. There are new indications that changes occur not only in the eyes but also in the brain of these patients, particularly in a structure that connects the two brain hemispheres. We plan to study the function of this brain structure in humans with glaucoma using a series of non-invasive tests.

This grant was transferred to Dr. Esther G. Gonzalez upon the passing of the original PI, Dr. Martin Steinbach in June 2017. The research project is being continued in Martin's memory.

Project Details

There is new research showing that glaucoma changes occur not only in the eyes but also in the brain, particularly in a structure that connects the two brain hemispheres called the corpus callosum. We plan to test the function of this brain structure with a series of noninvasive tests using a phenomenon called a binocular rivalry.

Briefly, binocular rivalry occurs when one stimulus is presented to one eye and a different stimulus to the other eye. Under this circumstance, the brain cannot combine the two stimuli into a stable binocular percept and the two images compete for perceptual dominance. Changes in eye dominance happen in a wave-like fashion and the initiation and speed of these “traveling waves” can be measured.

We plan to test rivalry dominance of stimuli presented centrally and in the periphery in eyes of individuals living with glaucoma. We will also measure intra and inter-hemispheric propagation of the traveling waves during rivalry. We have preliminary data showing that even in the early stages, the binocular rivalry of people with glaucoma is different from that experienced by people without this disease.

This project will examine the function of a brain structure that is not part of the primary visual pathway. Its dysfunction may suggest that additional degenerative mechanisms of glaucoma exist, which would be similar to those found in Alzheimer’s disease, for example.

If the hypotheses of this project are confirmed, in addition to broadening our understanding of glaucoma, the techniques introduced here may also be used for early diagnosis and for new approaches to glaucoma research and treatment. Our technique is easy to set up, requiring minimal equipment, and we will make available to others the methods we developed that enabled us to conduct our studies.

Glaucoma is known as the “silent killer of vision” because a large proportion of people are not aware that they have it until the late stages of the disease. It is therefore very important to detect glaucoma early so these patients can get help. It is also important to understand the disease in order to develop new lines of treatment.