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.
Therapeutic Control Of Pathological Myopia: Role Of Transforming Growth Factor-beta
Funder
National Health and Medical Research Council
Funding Amount
$312,730.00
Summary
Myopia (shortsightedness) 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. The optical consequences of myopia, namely blurred distance vision, are correctable with spectacles or contact lenses. However, a significant minority of individuals (3% of the Australian population) have excessively long eyes and high amounts of myopia. These enlarged eyes impose abnormal stresses on the s ....Myopia (shortsightedness) 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. The optical consequences of myopia, namely blurred distance vision, are correctable with spectacles or contact lenses. However, a significant minority of individuals (3% of the Australian population) have excessively long eyes and high amounts 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. Damage that occurs to the retina in these eyes is, at present, untreatable and irreversible and can result in blindness. Myopia is the 2nd leading cause of blindness amongst adults of working age. 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 a biochemically active process and not due to passive stretch. Before elongation of the eye can occur the biochemical structure of the sclera must change, a complex process involving accelerated production and breakdown of the biochemical building blocks of the sclera. Previous research in our laboratory indicates that changes in structure of the sclera are associated with reduced levels of the growth-controlling protein transforming growth factor-beta (TGF-beta). The aim of this project is to supplement TGF-beta levels in the sclera in order to reverse the loss of scleral tissue, stop the development of myopia and, therefore, prevent the development of the sight-threatening pathology associated with high myopia. In addition, we will determine the most effective way to deliver a sustained dose of TGF-beta to the sclera.Read moreRead less
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
Age Related Changes In The Optics Of Adult Human Eyes
Funder
National Health and Medical Research Council
Funding Amount
$199,437.00
Summary
Vision is limited by both optical and retinal-neural factors. Our understanding of the optical structure of the human eye is limited, partcularly for the refractive index gradient of the lens, let alone how these change with age. This understanding is needed if we are to accurately predict or assess the long-term effects of refractive surgical procedures or ophthalmic prostheses on vision. In this project, we aim to substantially improve our understanding of the optical properties of the eye by ....Vision is limited by both optical and retinal-neural factors. Our understanding of the optical structure of the human eye is limited, partcularly for the refractive index gradient of the lens, let alone how these change with age. This understanding is needed if we are to accurately predict or assess the long-term effects of refractive surgical procedures or ophthalmic prostheses on vision. In this project, we aim to substantially improve our understanding of the optical properties of the eye by 1) developing methods for measuring these quantities and then applying the methods to investigate how these properties vary with age and focussing, and 2) determine the optical contribution to reduction in visual performance with increasing age. Our research will be used to determine norms for growth and aging patterns in the normal human eye, particularly the lens. It will yield significant outcomes through 1. determination of the long-term success of custom refractive surgery aimed at improving vision by eliminating the ocular aberrations, and 2. indicating the potential improvement in ocular performance provided by artificial intraocular lenses or any other type of correction.Read moreRead less