Heritable Influences In Experimental Retinopathy Of Prematurity
Funder
National Health and Medical Research Council
Funding Amount
$272,591.00
Summary
Retinopathy of prematurity is an eye disease of very premature infants who require neonatal intensive care. It is a major cause of childhood blindness world-wide. Disease is caused by the growth of abnormal blood vessels in the retina, at the back of the eye. Currently, management involves the repeated examination of premature infants by an eye doctor. The babies are anaesthetized for this examination. If early disease is detected, then the affected eyes are treated with a medical laser, to burn ....Retinopathy of prematurity is an eye disease of very premature infants who require neonatal intensive care. It is a major cause of childhood blindness world-wide. Disease is caused by the growth of abnormal blood vessels in the retina, at the back of the eye. Currently, management involves the repeated examination of premature infants by an eye doctor. The babies are anaesthetized for this examination. If early disease is detected, then the affected eyes are treated with a medical laser, to burn the abnormal blood vessels. This stops the growth of these vessels and can prevent the child from going blind. However, the laser treatment itself can damage the eye. Left untreated, early retinopathy of prematurity will disappear of its own accord in some babies, but because they cannot currently be distinguished from those who will develop severe disease, all babies with signs of disease are treated. Not every premature infant develops retinopathy of prematurity: an as-yet unknown genetic factor controls susceptibility to disease. We plan to investigate this genetic basis using laboratory rats. Raised under the same conditions that are used in intensive care nurseries, baby rats develop eye disease that is similar to retinopathy of prematurity. However, as with human babies, not every baby rat develops this eye disease. We have shown a heritable tendency to retinopathy in different strains of rat. We identify the genes and proteins that differ amongst rats with or without the eye disease. We predict that identification of the inherited factors for retinopathy of prematurity in rats will provide strong clues to similar factors in humans. Our ultimate goal is to develop a test which will identify those human babies who are at risk of developing blinding retinopathy of prematurity, so that treatment is not given unnecessarily. We also expect to discover new targets for treatment.Read moreRead less
Control Of Refractive Error Through Ionically Driven Fluid Movements
Funder
National Health and Medical Research Council
Funding Amount
$208,600.00
Summary
Myopia affects about half the world's population with recent studies suggesting epidemic proportions among some Asian schoolchildren though we are not seeing this in Australia. Costs associated with detection, monitoring and optical correction of low and high myopia are huge. High myopes (15% with > 6D) also have a greatly increased risk of blindness between the ages of 30 and 50 years due to secondary disorders associated with impaired fluid balance (retinal and choroidal oedema, macula oede ....Myopia affects about half the world's population with recent studies suggesting epidemic proportions among some Asian schoolchildren though we are not seeing this in Australia. Costs associated with detection, monitoring and optical correction of low and high myopia are huge. High myopes (15% with > 6D) also have a greatly increased risk of blindness between the ages of 30 and 50 years due to secondary disorders associated with impaired fluid balance (retinal and choroidal oedema, macula oedema, retinal detachment and glaucoma). Currently there is no accepted pharmaceutical treatment for myopia though our studies in chick have provided the theoretical rationale and experimental data for a potential therapy and patent. This patent is now at the PCT stage and attests that changes in the abundance of the ions of the subretinal space control fluid movements across the retina to choroid and can be modulated therapeutically by diuretics to control fluid flow and hence axial growth and myopia. This application aims to take our current knowledge about fluid control in myopic chick into a mammalian model prior to preclinical trials in monkey. We anticipate it will take 1 year to establish the feasibility of diuretic control of experimentally induced myopic refractive errors in guinea pigs and the best drug and best the dosage range. These studies will contribute to the scientific understanding and bring the proposed pharmaceutical therapy for myopia in adults and children to a point of full commercialization. We believe that the results found in chick will have significance for early and late-onset myopia in humans as it is highly likely that the same mechanisms of ocular growth regulation operate throughout life.Read moreRead less
An Open-label Extension Of A Randomised Clinical Trail Of Intravitreal Triamcinolone For Diabetic Macular Oedema
Funder
National Health and Medical Research Council
Funding Amount
$167,733.00
Summary
A 25 fold increase in the risk of going blind on diagnosis of diabetes is one of the most daunting threats that patients face. Most cases of vision impairment in diabetes are due to macular oedema that persists or recurs after laser treatment. There are now a number of uncontrolled, anecdotal reports that intravitreal triamcinolone (IVTA) is highly effective for the treatment of diabetic macular edema which is refractory to conventional laser treatment. We commenced the first placebo-controlled, ....A 25 fold increase in the risk of going blind on diagnosis of diabetes is one of the most daunting threats that patients face. Most cases of vision impairment in diabetes are due to macular oedema that persists or recurs after laser treatment. There are now a number of uncontrolled, anecdotal reports that intravitreal triamcinolone (IVTA) is highly effective for the treatment of diabetic macular edema which is refractory to conventional laser treatment. We commenced the first placebo-controlled, double masked clinical trial of intravitreal triamcinolone for refractory macular oedema in 2002. The 3 month results from this study provide the first scientific proof of principle that intravitreal triamcinolone reduces macular thickness and improves vision. The two year results will be available in March 2005, but confidential interim analysis of efficacy data in September 2004 suggested that the beneficial effect of triamcinolone treatment persisted. Thus it appears that treatment with intravitreal triamcinolone may be the most significant development for the prevention of blindness in people with diabetes since the introduction of laser treatment. It would also be a highly cost-effective intervention that could be administered by general ophthalmologists. The treatment cannot be recommended for routine use, however, until its long term efficacy and safety have been established. Since we already have a well studied group of patients who have received treatment for 2 years, we are in a unique position to extend the study in order to provide the long-term (5-year) safety and efficacy data that does not appear to be forthcoming from any other source. The results of this study will significantly improve knowledge of long-term outcomes of local high dose steroids for diabetic macular oedema, allowing the treatment to be used more rationally. Thus the study is very likely to directly reduce the risk of blindness in people with diabetes.Read moreRead less