Properties Of Human Photoreceptors Measured Using A Scanning Laser Ophthalmoscope To Illuminate And Image The Retina
Funder
National Health and Medical Research Council
Funding Amount
$352,000.00
Summary
Vision begins with the detection of light by the rod and cone photoreceptors in the retina lining the interior of the eye. Although much is already known about the way that light is detected and the signals are processed, a great deal remains to be learned. Some of the outstanding questions could be answered using modifications to a relatively new instrument called a scanning laser ophthalmoscope (SLO) which provides images of the interior of the eye. The aims of this project are to develop a mo ....Vision begins with the detection of light by the rod and cone photoreceptors in the retina lining the interior of the eye. Although much is already known about the way that light is detected and the signals are processed, a great deal remains to be learned. Some of the outstanding questions could be answered using modifications to a relatively new instrument called a scanning laser ophthalmoscope (SLO) which provides images of the interior of the eye. The aims of this project are to develop a modified SLO, which is able to measure the levels of visual pigment (rhodopsin) in the living eye, which is also able to deliver visual stimuli to the eye, and which finally is extended to use adaptive optics so that it can image and excite individual cone photoreceptors. Using this device, we will be able to measure the regeneration of visual pigment following exposures to intense illumination, to help explain the slow recovery of visual sensitivity after intense light. We will also be able to measure the electroretinogram (ERG) from localized retinal areas, to investigate how the properties of the photoreceptor cells vary across the retina. And finally we will be able not only to visualize the individual tiny cone photoreceptors, but also to stimulate them selectively, so that we can determine the responses of the different classes of cone (red-, green-, and blue-sensitive cones) in the living human eye.Read moreRead less
The Blood-Retinal Barrier - Modelling Mechanisms For Maintenance, Breakdown And Repair
Funder
National Health and Medical Research Council
Funding Amount
$394,310.00
Summary
We believe that breakdown of the barrier that separates the delicate nervous tissue of the eye from the bloodstream, the blood-retinal barrier, may be an early event in the development of age-related macular degeneration (AMD), now overall the commonest cause of blindness in Australia. We have recently demonstrated with the first scientific clinical trials to be conducted in the world that an injection of steroid into the jelly of the eye, or vitreous , of the steroid triamcinolone slows the gro ....We believe that breakdown of the barrier that separates the delicate nervous tissue of the eye from the bloodstream, the blood-retinal barrier, may be an early event in the development of age-related macular degeneration (AMD), now overall the commonest cause of blindness in Australia. We have recently demonstrated with the first scientific clinical trials to be conducted in the world that an injection of steroid into the jelly of the eye, or vitreous , of the steroid triamcinolone slows the growth of abnormal blood vessels in patients with wet AMD. In the current project, Prof Nick King, a cell biologist and viral immunologist, will collaborate with Dr Michelle Madigan, A-Prof Jan Provis, both experts in experimetnal AMD, and A-Prof Mark Gillies, a clinician-scientist specialising in AMD, to study how the treatment works using established animal and laboratory models of a damaged blood retinal barrier. We will be particularly interested in processes which are thought to critical in the development these diseases. We will also study newly described processes by which the junctions that seal the cells of the barrier together come apart. We will be interested not just in the cells that make the barrier, but also the effect of nearby cells that are thought to contribute to it. These studies will provide a solid foundation for the rationalisation of steroid treatment for AMD which can be expected to result in improved outcomes for our patients. The studies may also provide insights into how other barriers malfunction, such as the blood brain barrier which breaks down in Alzheimer s disease and multiple sclerosis.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.