The Role Of Integrins In The Regulation Of Scleral Remodelling During Pathological Myopia Development
Funder
National Health and Medical Research Council
Funding Amount
$234,750.00
Summary
Myopia (short-sightedness) is due to the eye being too long. It is a common refractive disorder, affecting some 25-30% of people in developed countries, and results in blurred distance vision. Most myopia is easily corrected with spectacles or contact lenses. However a small, but significant, group of individuals (in Australia, 1-2% of people) have high degrees of myopia. These enlarged eyes impose abnormal stresses on the structures inside, particularly affecting the retina which is the light s ....Myopia (short-sightedness) is due to the eye being too long. It is a common refractive disorder, affecting some 25-30% of people in developed countries, and results in blurred distance vision. Most myopia is easily corrected with spectacles or contact lenses. However a small, but significant, group of individuals (in Australia, 1-2% of people) have high degrees of myopia. These enlarged eyes impose abnormal stresses on the structures inside, particularly affecting the retina which is the light sensitive part of the eye. Any damage that occurs to the retina in these eyes is, at present, untreatable and irreversible and can result in blindness. In fact, myopia is the 2nd leading cause of blindness amongst adults of working age. In order for the eye to grow so large its white, outer coat (the sclera) must expand without allowing any leaks of the delicate structures and fluids inside. Although the sclera gets very thin as it expands, it has been shown that this process of expansion is not just due to stretching. Before any stretching can occur the biochemical structure of the sclera must change and this is a complex process, driven by the scleral cells and involving the synthesis of structural components and activity of enzymes which breakdown scleral structure. The aim of this project is to investigate the role of specific scleral proteins (integrins) in high myopia. Integrins reside on the surface of the scleral cells and communicate information about the changes going on in the surrounding sclera. We predict these proteins are important in keeping the cell informed of the local biochemical and biomechanical changes in the sclera and in driving the cell to rapidly adapt to these changes. The project will provide a greater understanding of the process of scleral thinning in high myopia and allow us to test the potential of integrins as therapeutic targets in the sclera, thereby giving us the opportunity of preventing blindness in a number of highly myopic individuals.Read moreRead less
Oculomotor Tests Of Otolith Function Using Human Centrifugation
Funder
National Health and Medical Research Council
Funding Amount
$284,450.00
Summary
The effects of dysfunction of the balance system of the inner ear (the vestibular system) can range from mild brief episodes of dizziness to almost complete incapacitation: where the patient feels unstable, their posture is unstable, their vision is unstable. In order to guide appropriate treatment and rehabilitation, diagnostic tests are needed to identify whether the dysfunction is due to a brain problem or a problem in the inner ear, and if an ear problem - which part of the inner ear system ....The effects of dysfunction of the balance system of the inner ear (the vestibular system) can range from mild brief episodes of dizziness to almost complete incapacitation: where the patient feels unstable, their posture is unstable, their vision is unstable. In order to guide appropriate treatment and rehabilitation, diagnostic tests are needed to identify whether the dysfunction is due to a brain problem or a problem in the inner ear, and if an ear problem - which part of the inner ear system is affected. By combining basic research with clinically feasible methods my colleagues and I have, with NH and MRC support, developed some of the most widely used clinical tests of balance function available today (see Halmagyi, Cremer and Curthoys 2003 for a review). In this Project I seek to continue the development of a test of part of the balance system (the utricular macula) for which there are few acceptable tests. I will do that by using the unique facilities available at Sydney University and RPA Hospital, presenting controlled stimuli (linear accelerations) to healthy human subjects and patients with known vestibular losses, and measuring precisely their eye movement responses to these stimuli using computerized image processing techniques. The experiments will test an hypothesis about how part of the vestibular system, the utricular macula, works and controls eye movements. One eye movement response, rolling of the eye around the line of sight (called ocular torsion) during maintained roll head-tilts (to the patients left or right) may be due to the joint activation of two regions of the balance receptors: the utricular and saccular maculae. As a result of a recent direct test we have managed to conduct on two normal subjects, we think that hypothesis should be thoroughly re-tested on subjects and patients with known vestibular losses and in doing so provide new understanding of otolith function which may lead to new clinical tests.Read moreRead less
Effects Of Saccadic Eye Movements On Perception And Visual Memory.
Funder
National Health and Medical Research Council
Funding Amount
$255,750.00
Summary
We all make rapid eye movements, called saccades, three times a second all our waking lives. They allow us to direct our gaze at what catches our attention, but they sweep images across our retinas and alter all the linkages between the eyes and the brain. The question at the heart of this project is how the visual system maintains perceptual stability given the disruption to the flow of visual input that saccades necessarily cause. It has to do more than suppress disturbing signals; it has to l ....We all make rapid eye movements, called saccades, three times a second all our waking lives. They allow us to direct our gaze at what catches our attention, but they sweep images across our retinas and alter all the linkages between the eyes and the brain. The question at the heart of this project is how the visual system maintains perceptual stability given the disruption to the flow of visual input that saccades necessarily cause. It has to do more than suppress disturbing signals; it has to link the present with the past. In recent years we and others have made substantial progress toward answering this question. In this project we plan a four-pronged attack that will take us further. We anticipate that our results will reveal how the visual system maintains and adjusts its representations of space and time, integrates signals from before and after saccades, and regulates the flow of information from memory to achieve a seamless melding of the present with the past. This project is not directed at any particular clinical problem, but disturbances of perception and memory are aspects of many clinical conditions. If we succeed in our aims what we discover will constitute a major scientific discovery which should find application to many conditions in which perception and memory are disturbed, from dyslexia to brain damage and even affective disorders such as schizophrenia and depression.Read moreRead less