Characterising The Changes In Regulation Of Visual Contrast Sensitivity In Glaucoma.
Funder
National Health and Medical Research Council
Funding Amount
$337,600.00
Summary
Glaucoma is the second leading cause of blindness in developed nations. A recent study estimated the number of Australian's that will need regular visual examination in 2030 either because they have glaucoma or glaucomatous risk factors to be at least 800,000. As the ultimate aim of glaucoma treatment is to maintain vision, visual functional assessment is of paramount importance to glaucoma management . The current standard measure for the assessment of visual loss due to glaucoma is visual fiel ....Glaucoma is the second leading cause of blindness in developed nations. A recent study estimated the number of Australian's that will need regular visual examination in 2030 either because they have glaucoma or glaucomatous risk factors to be at least 800,000. As the ultimate aim of glaucoma treatment is to maintain vision, visual functional assessment is of paramount importance to glaucoma management . The current standard measure for the assessment of visual loss due to glaucoma is visual field testing. Regrettably, substantial damage to retinal ganglion cells (the primary neurons affected by glaucoma) is often present prior to the discovery of visual field loss using standard measures. Indeed studies have demonstrated that even 30-50% retinal ganglion cell loss may only manifest as a mild visual field deficit using current standard testing. This project will use novel techniques for exploring sight impairment in glaucoma, enabling a better understanding of the underlying neural damage. Our pilot work demonstrates that these methods can detect loss of sight in areas diagnosed as normal using standard visual field testing. The study will provide new technologies for the assessment of early vision loss due to glaucoma that may enable the detection of malfunction of retinal ganglion cells prior to their death. Such measures of neural malfunction are essential to establishing the efficacy of new pharmacological therapies (known as neuroprotective agents) for glaucoma aimed at keeping retinal ganglion cells alive and functioning. This project also has the potential to identify visual measures that have better capability for monitoring the progression of vision loss due to glaucoma. Early detection of glaucoma and its progression is essential so that treatment can be initiated or altered, slowing the progression of vision loss and its toll on both the individual and the community.Read moreRead less
Lesions of the primary visual area (V1) are sufficient to cause blindness, even though there are many other brain areas normally involved in vision. However, when V1 is lesioned very early in life people show some recovery, and may be able to see well enough to perform everyday activities. In order to understand what happens in the brain that allows this preservation of vision, we will study changes in the pathways linking the eyes to the brain, following lesions at different ages.
Over thirty different areas, comprising nearly half the primate cerebral cortex, are involved in processing visual information. From the anatomical viewpoint, each of these areas should be capable of receiving visual information independently, through parallel anatomical channels involving the brainstem. Yet, it has been observed that lesion of one particular area (the primary visual area, V1) results in loss of vision. This raises several questions. What type of visual information is carried by ....Over thirty different areas, comprising nearly half the primate cerebral cortex, are involved in processing visual information. From the anatomical viewpoint, each of these areas should be capable of receiving visual information independently, through parallel anatomical channels involving the brainstem. Yet, it has been observed that lesion of one particular area (the primary visual area, V1) results in loss of vision. This raises several questions. What type of visual information is carried by the parallel pathways to the other visual areas? Why aren t these other areas capable of sustaining vision without V1? Do V1 lesions trigger changes in the adult brain, which affect the other visual areas? As a step towards answering these questions, we will study the neural pathways that convey visual information directly to the middle temporal area (MT). MT is one of the best-characterised visual areas, and the anatomy of its neural inputs is well known, facilitating the interpretation of the results. We will investigate the type of visual information being sent to MT after lesions of V1, as well as the changes in the electrical responses of MT cells which result from this type of condition. This is a basic science study, the primary benefit of which will be advancement of knowledge on the mechanisms that underlie visual processing in normal and pathological situations. However, this type of work may also lay the groundwork for developments in areas of applied research. These may include medicine (e.g. the design of better rehabilitation strategies for people with brain damage), robotics- artificial intelligence (e.g. the development of more robust artificial systems capable of vision), and cognitive sciences (e.g. a better understanding of factors that limit human responses to visual stimuli).Read moreRead less
Cortical Interactions Between Afferent Channels In Macaque Visual System
Funder
National Health and Medical Research Council
Funding Amount
$380,154.00
Summary
There are three distinct groups of cells that carry the visual information from the eyes to the brain, each pathway signaling a different aspect of the visual scene. This project will study in detail the lesser known of these three pathways (koniocellular neurones): what sort of information they carry into the brain, how it is combined with the other pathways to yield our composite picture and where in the brain such combination takes place.
Functional Connectivity Between Visual Cortical Areas In The Non-human Primate
Funder
National Health and Medical Research Council
Funding Amount
$387,585.00
Summary
Visual information going from the eyes to the brain is processed in different parts of the brain to extract useful information. However, to be able to select what is important from among the vast number of objects in the scene, top-down signals from higher areas need to act on incoming signals in earlier areas. This project aims to identify what sort of neural pathways are involved in this and how it is done at the cellular level.
Optimising The Detection Of Early Glaucoma - Targeting Specific Visual Pathways In Combination With Structural Measures.
Funder
National Health and Medical Research Council
Funding Amount
$481,893.00
Summary
This study seeks to determine the optimal methods for detecting early glaucoma - a blinding disease - using new and diverse strategies for selective testing of specific visual pathways, in combination with structural analysis for optic nerve fibre loss. We hope to identify the best combination of available tests to enable earliest identification of glaucomatous damage.
The Role Of Ten-m3 In Patterning Ipsilateral Retinal Projections
Funder
National Health and Medical Research Council
Funding Amount
$453,042.00
Summary
The normal functioning of the brain depends on connections of billions of nerve cells or neurons. We have found that a protein called Ten_m3 plays a very important role in specifying the way that neurons from the eye connect to the brain. The role of this protein is so important that mice which lack the protein behave as if they are blind. The aim of this project is to understand how this protein controls the development of the visual system.
Clinical Trial Of A Suprachoroidal Visual Prosthesis For The Profoundly Vision Impaired
Funder
National Health and Medical Research Council
Funding Amount
$1,098,802.00
Summary
For 15 years we have been designing a bionic eye. We have made a device called the Phoenix99 and shown in short term animal tests that it is both safe to implant but also that it potentially performs better than any other device in the world. We are requesting funds to complete longer term animal testing of the device and then commence a small human clinical trial to demonstrate the benefits of the technology – specifically that it is able to help blind people navigate without assistance.
DISSECTING THE GENETICS OF GLAUCOMA AND ITS RISK FACTORS USING A TWIN STUDY.
Funder
National Health and Medical Research Council
Funding Amount
$682,850.00
Summary
Glaucoma is one of the leading causes of blindness both in Australia (affecting 2-3% of the population) and worldwide. Glaucoma is often asymptomatic until it causes permanent loss of peripheral vision that precludes 10% of individuals with the condition from holding a driver's license. Around 50% of people with glaucoma are unaware that they have the condition; therefore better screening strategies are required. Genetic factors have been shown to contribute to glaucoma and our work has revealed ....Glaucoma is one of the leading causes of blindness both in Australia (affecting 2-3% of the population) and worldwide. Glaucoma is often asymptomatic until it causes permanent loss of peripheral vision that precludes 10% of individuals with the condition from holding a driver's license. Around 50% of people with glaucoma are unaware that they have the condition; therefore better screening strategies are required. Genetic factors have been shown to contribute to glaucoma and our work has revealed that 50% of people with glaucoma have a family history of the condition. Raised intraocular pressure (IOP) is a major contributing factor in glaucoma. Although there are some genes associated with high-pressure glaucoma, little is known about the heritability of IOP itself. Optic disc cupping is another important sign in the diagnosis and management of glaucoma, but again little is known of the inheritance of this feature. Twin studies, (comparing sets of identical twins with non-identical twins); allow us to estimate the relative contribution of genetic and environmental factors to disease states or physiological measurements. Although there have been small studies involving twins with glaucoma, it is unknown to what degree the basic parameters of glaucoma diagnosis such as IOP and optic disc characteristics are heritable. This project aims to conduct a large twin study into glaucoma and its associated ocular risk factors, including refractive error. We aim to identify genes that predispose to glaucoma, which will facilitate better screening for glaucoma in family members, and the general population, and ultimately leading to improved treatment.Read moreRead less
Genomic Signposts, High-resolution Sequencing And Novel Genes In Eye Disease
Funder
National Health and Medical Research Council
Funding Amount
$333,694.00
Summary
Blindness is a very distressing sensory loss. Hereditary eye disorders account for the vision impairment in at least one-third of people who are registered as blind. These disorders cause blindness from a young age and work productivity is significantly impaired. This project will identify novel genetic factors in blinding eye disorders. Identifying these genetic factors will lead to better early detection methods for people and improved treatments to prevent the blindness.