Modulating Retinal Glutamate Transport In Health And Disease
Funder
National Health and Medical Research Council
Funding Amount
$256,527.00
Summary
Damage can occur to nervous tissues like the retina and brain when there is a reduction in the blood supply. This can occur as a result of a blood clot, stroke or the eye disease, glaucoma. These conditions often result in blindness. Much of the neuronal damage is due to the release of an excess of glutamate. Glutamate is a chemical (neurotransmitter) that nerves use to communicate with each other, but it is toxic to nerves when present at high concentrations. This project will investigate the m ....Damage can occur to nervous tissues like the retina and brain when there is a reduction in the blood supply. This can occur as a result of a blood clot, stroke or the eye disease, glaucoma. These conditions often result in blindness. Much of the neuronal damage is due to the release of an excess of glutamate. Glutamate is a chemical (neurotransmitter) that nerves use to communicate with each other, but it is toxic to nerves when present at high concentrations. This project will investigate the mechanisms that regulate the concentration of glutamate in the retina. If these mechanisms could be made to work more efficiently, they may prevent the build-up of the glutamate and therefore prevent damage to the nerve cells. Understanding these mechanisms will aid in the development of an effective treatment to prevent blindness when there is a blockage of the blood supply to the retina.Read moreRead less
INTRARETINAL OXYGEN CONSUMPTION AND THE PREVENTION OF HYPOXIA IN RETINAL ISCHEMIA
Funder
National Health and Medical Research Council
Funding Amount
$164,444.00
Summary
Adequate oxygen supply to the retina is critical for normal visual function. The oxygen is normally supplied by the blood flowing in the two circulations that support the retina. These are the choroidal circulation, lying behind the retina, and the retinal circulation, which supports the front half of the retina. The retinal circulation is particularly vulnerable to vascular disease and insufficient blood flow (ischemia). Vascular changes are involved in a wide range of retinal diseases which ar ....Adequate oxygen supply to the retina is critical for normal visual function. The oxygen is normally supplied by the blood flowing in the two circulations that support the retina. These are the choroidal circulation, lying behind the retina, and the retinal circulation, which supports the front half of the retina. The retinal circulation is particularly vulnerable to vascular disease and insufficient blood flow (ischemia). Vascular changes are involved in a wide range of retinal diseases which are currently responsible for the majority of new blindness in our community. The choroidal circulation is relatively robust, and offers a potential avenue for increasing oxygen delivery to the retina in the clinical management of ischemic retinal diseases. The feasibility of such an approach is strongly dependent on the oxygen requirements of the retina, and how this is influenced by retinal ischemia. We plan to find out how much oxygen is consumed by the many different layers within the retina under normal conditions and then determine how this changes under ischemic conditions. We will then see if we can supply enough oxygen from the choroid by a combination of raising the oxygen content of the blood, increasing choroidal blood flow, and reducing the amount of oxygen used by the outer half of the retina. Our experiments will be done in laboratory rats, but the same principles are readily transferable to humans if they prove to be beneficial in protecting the retina from ischemic damage. Our study will also quantify the relationship between oxygen levels in the blood stream, and those in the different layers of the retina. This information may prove valuable in the treatment and the prevention of other retinal diseases where the manipulation of the intraretinal oxygen environment is an exciting new avenue of research.Read moreRead less
Retinal Endothelial Cell Changes That Precede Retinal Vein Occlusion And The Retinal Extracellular Space Changes That Follow It
Funder
National Health and Medical Research Council
Funding Amount
$118,121.00
Summary
Dr. Min Hye Kang, at The University of Western Australia, is investigating microscopic blood vessel changes that precede the onset of devastating blindness. She is also studying functional changes that occur in the retina following deprivation of its blood supply. Her research has significantly improved our understanding of cellular mechanisms that lead to blindness. It has also aided in the development of new treatment strategies for the prevention of vision loss.
New Dynamometric Techniques For Predicting Glaucoma Progression
Funder
National Health and Medical Research Council
Funding Amount
$171,825.00
Summary
Glaucoma is a major cause of blindness in our community. The biggest risk factor for glaucoma is raised intraocular pressure. However, the exact cause of the disease remains unknown. Through our basic science studies in animals we have discovered that changes in blood flow in the vessels at the optic disk may be involved in the disease process. In recent clinical trials we discovered that the presence or absence of pulsations in the retinal veins at the disk was both an indicator of severity and ....Glaucoma is a major cause of blindness in our community. The biggest risk factor for glaucoma is raised intraocular pressure. However, the exact cause of the disease remains unknown. Through our basic science studies in animals we have discovered that changes in blood flow in the vessels at the optic disk may be involved in the disease process. In recent clinical trials we discovered that the presence or absence of pulsations in the retinal veins at the disk was both an indicator of severity and progression of glaucoma. This is a major breakthrough because there is no other means of predicting in which glaucoma patients vision loss will develop most rapidly. This information will be very helpful in deciding which patients should have the most agressive treatment to restore normal intraocular pressure. This project seeks to develop a new commercial device to make such an examination easy for any clinical ophthalmologist. The device allows the doctor to examine the vessels at the disk whilst applying slight pressure to the eye to temporarily raise intraocular pressure. A footswitch is pressed when the doctor sees the vessels pulsate. The required force is recorded by a laptop computer and the data stored along with the patients details. Now we have confirmed the ability of such a measurement to predict the rate of visual field loss in glaucoma, such a measurement will become much more widespread in clinical ophthalmology, offering a new and large scale opportunity for such instrumentation. Our device will be easy to operate, more comfortable for the patient, and will be of major diagnostic value in glaucoma clinics worldwide.Read moreRead less
The Cellular Organisation Of Interneurones In Human Retina
Funder
National Health and Medical Research Council
Funding Amount
$526,454.00
Summary
Our goal is to determine the numbers and types of nerve cells in the human retina: the part of the eye where visual processing starts. This data will serve as a baseline against which effects of visual disease can be measured.
Validating A Prototype Laser System For Intraocular Surgery
Funder
National Health and Medical Research Council
Funding Amount
$495,551.00
Summary
Intraocular surgery is a vital tool for treating common sight threatening diseases such as proliferative diabetic retinopathy and retinal vein occlusion. We seek to develop a prototype laser system to replace currently used mechanical instruments. We have demonstrated that UV laser ablation can afford much greater precision. Laser parameters for the new system will be optimised based on our previous achievements. The new system will be tested in animal trials and clinically.
Glial-neuronal-vascular Interactions In A Novel Transgenic Model Of Muller Cell Dysfunction
Funder
National Health and Medical Research Council
Funding Amount
$626,585.00
Summary
Muller cell disfunction is a feature shared by many retinal diseases. This project aims to study the contribution of Muller cell dysfunction to retinal neuronal damage and blood-retinal barrier breakdown in a novel transgenic model we recently generated. Results of this study will also be of interest to scientists and clinicians seeking to understand better and treat diseases of the central nervous system in general.
The Role Of Gliosis In Advanced Retinal Degeneration
Funder
National Health and Medical Research Council
Funding Amount
$457,785.00
Summary
The development of treatments that restore vision assumes that the output neurons of the retina remain intact. Yet, there is now considerable evidence that the neurons that signal from the retina to the brain are altered in those that have degenerative diseases of the retina. Here, we will examine the cause of these cellular changes in an animal model and seek to prevent the loss of output neurons. This information is crucial for the development of treatments that seeks to restore vision.