The Mechanism Of Action Of Muscarinic Receptor Antagonists In Preventing Axial Myopia
Funder
National Health and Medical Research Council
Funding Amount
$242,545.00
Summary
Myopia (short-sightedness) is the most common refractive error and is due to the eye being too long and, if uncorrected, results in blurred distance vision. Approximately 30% of the population in developed countries, such as Australia, suffer from myopia. In a significant minority of individuals with high degrees of myopia, it is a sight threatening condition and a leading cause of blindness. It has been found that the pharmacological agent, atropine, is effective in preventing myopia in childre ....Myopia (short-sightedness) is the most common refractive error and is due to the eye being too long and, if uncorrected, results in blurred distance vision. Approximately 30% of the population in developed countries, such as Australia, suffer from myopia. In a significant minority of individuals with high degrees of myopia, it is a sight threatening condition and a leading cause of blindness. It has been found that the pharmacological agent, atropine, is effective in preventing myopia in children and in animal models of myopia. However the side effects of blurred vision at near, glare from dilated pupils and the unknown long term effects of chronic atropine treatment have prevented this approach to myopia control from becoming an established treatment in children. It was originally thought that the drug worked by preventing the eye from accommodating for near objects, however it has now been shown that atropine does not to work by this mechanism, but rather by another non-accommodative mechanism. The aim of this project is to determine the mechanism of action of this class of drugs (known as muscarinic antagonists) in preventing myopic eye growth. The project will investigate in which ocular tissues the various subtypes of muscarinic receptors sensitive to these drugs are located and how these are changed in myopic eyes. It will also determine the specific receptor subtype these drugs act on and whether these drugs inhibit eye growth in myopia by altered retinal signalling activity. The results from this study will elucidate the mechanism and route of action of muscarinic antagonists in preventing myopic eye growth. These findings will advance the probability of developing an effective selective muscarinic antagonist drug to use for the prevention of axial myopia without the side effects associated with the broad-band antagonist atropine. The development of such drugs will have a major economic benefit to the Australian population.Read moreRead less
A Randomised Controlled Falls Prevention Trial Of Long Distance Glasses In Elderly Multifocal Wearers
Funder
National Health and Medical Research Council
Funding Amount
$493,000.00
Summary
Each year, one-third to a half of people over 65 years old will fall at least once. The consequences of falls are immense in terms of suffering, loss of independence, fear of future falls, carer burden, mortality, residential care admissions and other health care resource usage. Clearly, effective and affordable falls prevention strategies are needed to address this major health care problem. Over 50% of people over 65 years old use bi-, tri- or multi-focal glasses. The lower part of these glass ....Each year, one-third to a half of people over 65 years old will fall at least once. The consequences of falls are immense in terms of suffering, loss of independence, fear of future falls, carer burden, mortality, residential care admissions and other health care resource usage. Clearly, effective and affordable falls prevention strategies are needed to address this major health care problem. Over 50% of people over 65 years old use bi-, tri- or multi-focal glasses. The lower part of these glasses are useful for reading and seeing at close range only and there is now evidence that the use of these glasses is associated with an increased risk of falls due to the blurring of vision when looking through the lower lenses at ground level obstacles. This is particularly relevant in unfamiliar outdoor situations. This study will determine whether providing plain distance glasses (with extensive counselling and recommendations for use in standing and walking activities) will prevent falls and their consequences over a one year period in older persons who wear bi-, tri- or multi-focal glasses. Pilot studies suggest that most elderly bi-, tri-, or multi-focal wearers at risk for falls are willing to purchase and use a second pair of glasses if the benefit of new plain distance glasses for their vision is demonstrated. We expect that the results of the study will be incorporated into all relevant areas of clinical practice and public health strategies.Read moreRead less
Structure And Function Of The Third Geniculocortical Pathway In Primates.
Funder
National Health and Medical Research Council
Funding Amount
$296,777.00
Summary
Our understanding of the human visual system has been based on the idea that there are two main nerve pathways from the eye to the brain. One, called the parvocellular pathway, is for colour and detail vision, and the other, called the magnocellular pathway, is for movement perception. Damage to either pathway by disease such as glaucoma, or a lesion such as stroke, will cause specific changes in visual perception and these changes can be used to diagnose the nature of the disease or lesion. We ....Our understanding of the human visual system has been based on the idea that there are two main nerve pathways from the eye to the brain. One, called the parvocellular pathway, is for colour and detail vision, and the other, called the magnocellular pathway, is for movement perception. Damage to either pathway by disease such as glaucoma, or a lesion such as stroke, will cause specific changes in visual perception and these changes can be used to diagnose the nature of the disease or lesion. We will study a recently recognised third subdivision of the visual pathway, called the koniocellular pathway. The properties of koniocellular cells have not previously been studied in anthropoid primates, and their importance for human vision is not well understood. We will study the way that koniocellular cells respond to moving and patterned stimuli, and their connections with the cerebral cortex, in order to determine whether this pathway could contribute to aspects of normal and abnormal visual perception. We will follow up our preliminary evidence that koniocellular cells respond to visual stimuli of the type used to diagnose the early stages of eye diseases such as glaucoma. The results will give us a better understanding of the way that the nervous system processes visual information, and will clarify the basis of disturbances to normal visual function.Read moreRead less
Targeting At Risk Relatives Of Glaucoma Patients For Early Diagnosis And Treatment (TARRGET)
Funder
National Health and Medical Research Council
Funding Amount
$595,375.00
Summary
Glaucoma is the second leading cause of blindness in Australia but early detection and treatment can prevent blindness. We will recruit patients with advanced glaucoma from an Australia wide registry and refer their close relatives to have an eye exam and genetic testing to see if they are at risk of glaucoma. We will evaluate how a coordinator can improve the uptake of this screening program referring people to local eye care providers and in rural WA providing screening in 16 remote locations.
Origin And Specificity Of Neuronal Signals For Colour Vision In Primates.
Funder
National Health and Medical Research Council
Funding Amount
$490,500.00
Summary
How do we see colours? What do colour blind people see? Although colour is one of the most important attributes of objects in the visual world, the way that colour is processed in the brain is poorly understood. The aim of this project is to study the way that nerve cells in the eye (the retina) and the visual part of the brain are specialised to transmit signals for colour perception. The visual system of humans and other primates includes nerve cells which are selective for a limited range of ....How do we see colours? What do colour blind people see? Although colour is one of the most important attributes of objects in the visual world, the way that colour is processed in the brain is poorly understood. The aim of this project is to study the way that nerve cells in the eye (the retina) and the visual part of the brain are specialised to transmit signals for colour perception. The visual system of humans and other primates includes nerve cells which are selective for a limited range of wavelengths reflected by objects in the visual world. We will study how this selectivity is generated, by examining how the colour receptors are connected within the retina to the cells which transmit nerve impulses to the brain. Between 5 and 7 percent of male humans have colour vision defects. Many objects which appear clearly different to colour-normal observers cannot be discriminated by colour-defective observers, and entry to professions such as the police and airline industry is restricted for individuals with colour vision defects. We will study the basis of reduced colour perception ability in red-green colour blindness. This will be done by measuring the responses of nerve cells in a species of primate (marmoset) in which many animals have colour vision receptors resembling those of humans with colour vision defects. We will measure the reliability with which individual neurones can transmit signals for colour vision when they receive input from such abnormal receptors. It is known that nerve cells transmit their message within the brain by means of brief electrical impulses called action potentials. In addition to studying the basis of human colour discrimination, the project also addresses one of the fundamental questions of sensory processing, by studying the reliability of the coded message carried by action potentials within the central nervous system.Read moreRead less
3D Diffusion Models for Generating and Understanding 3D Scenes. Diffusion models, such as DALL-E2 and Imagen, have achieved remarkable success in generating photorealistic images and hold promise to solve long-standing computer vision problems. However, 3D scene generation remains unexplored. This research project aims to bridge the gap by developing 3D diffusion models capable of generating complete 3D scenes. This will advance our theoretical understanding of diffusion in complex 3D environmen ....3D Diffusion Models for Generating and Understanding 3D Scenes. Diffusion models, such as DALL-E2 and Imagen, have achieved remarkable success in generating photorealistic images and hold promise to solve long-standing computer vision problems. However, 3D scene generation remains unexplored. This research project aims to bridge the gap by developing 3D diffusion models capable of generating complete 3D scenes. This will advance our theoretical understanding of diffusion in complex 3D environments and open up new possibilities for applications in fields such as virtual reality, architecture, and city planning. The proposed 3D diffusion models will also enhance the accuracy of computer vision tasks related to 3D scene understanding, such as object detection, tracking, and semantic segmentation.Read moreRead less
Myopia And Colour Vision: Potential Impact Of Colour Vision Gene Variation On Susceptibility To Myopia
Funder
National Health and Medical Research Council
Funding Amount
$227,947.00
Summary
The frequency of myopia has shown a rapid increase in recent years but the underlying cause remains largely unknown. Our recent work on severe myopia with dichromacy has indicated that some forms of myopia may arise through changes in cone visual pigments and the arrangement of cone photoreceptors in the retina which impact on the feedback loop between image formation and eye elongation. This study seeks to explore this link in detail in myopia patients that possess normal colour vision.