Ophthalmology (Eye & Ear Hospital) - Research Publications
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ItemAcute hemorrhagic conjunctivitis due to enterovirus 70 in India.(Centers for Disease Control and Prevention (CDC), 1999)An outbreak of acute hemorrhagic conjunctivitis occurred in Delhi, India, during August and September 1996. The etiologic agent was confirmed as enterovirus type 70 by a modified centrifugation-enhanced culture method followed by immunofluorescence and neutralization tests. After nearly a decade, this virus is reemerging as a cause of acute hemorrhagic conjunctivitis in India.
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ItemLOSS OF HETEROZYGOSITY AT 11P13 IN WILMS-TUMORS DOES NOT NECESSARILY INVOLVE MUTATIONS IN THE WT1 GENE(STOCKTON PRESS, 1993-06)Loss of heterozygosity (LOH) in tumour cells is generally accepted as 'exposing' recessive cancer genes. The short arm of chromosome 11 shows consistent LOH in Wilms' tumours along its entire length. Occasionally, however, only the 11p13 and/or the 11p15 regions are involved. Deletions of the 11p13 region consistently predisposes to Wilms' tumorigenesis. We have analysed the recently cloned WT1 gene from the 11p13 region exon-by-exon in five tumours previously shown to have undergone LOH for the 11p13 region, using single strand conformation polymorphism analysis (SSCP) and PCR sequencing. Our analysis using SSCP failed to identify any band shifts in the WT1 gene from these tumours. In addition we also sequenced the zinc finger region of WT1, which is the part of the gene most frequently showing mutations. Only the normal sequence was found in all of these tumours. These results demonstrate that LOH in Wilms' tumours is not always related to mutations in the WT1 genes and argues strongly that another gene, probably in the 11p15 region, may be more important in Wilms' tumorigenesis.
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ItemMOLECULAR-GENETIC ANALYSIS OF CHROMOSOME 11P IN FAMILIAL WILMS-TUMOR(STOCKTON PRESS, 1994-06)In the family reported here, a mother and both of her children developed a Wilms tumour, and all three tumours were of the relatively rare monomorphous epithelial histopathological subtype. Using restriction fragment length polymorphism analysis, both sibs were shown to inherit the same maternal allele from the 11p13 region but different maternal alleles from the 11p15 region. Using a combination of single-strand conformation polymorphism (SSCP) and polymerase chain reaction (PCR) sequencing techniques, no mutations were identified in the WT1 tumour-suppressor gene from the 11p13 region, but a novel polymorphism was identified in exon 1. mRNA expression studies using the insulin-like growth factor II (IGF-II) gene, located in 11p15, showed that there was no relaxation of imprinting at this locus. There was also no evidence of loss of heterozygosity on the long arm of chromosome 16. These findings indicate that the WT1 and IGF-II genes, together with the long arm of chromosome 16, are not directly implicated in tumorigenesis in this Wilms family, but that a recombination event has occurred on the short arm of chromosome 11.
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ItemKnowledge, attitudes, and self care practices associated with age related eye disease in Australia(BMJ Publishing Group, 1998)Aim: To determine the level of correct knowledge about common eye disease and attitudes towards blindness prevention and treatment, and how these factors influence self care practices in a population based sample.Methods: A cluster random sample of the Victorian population was interviewed. The study population comprised residents aged 40 years of age or older living in five randomly selected Melbourne metropolitan suburbs and four randomly selected rural areas of Victoria. Questions were asked to ascertain each person's knowledge of common age related eye disease - that is, cataract, age related macular degeneration (AMD), and glaucoma. A subsample of the population was also asked questions to determine their attitudes to blindness prevention and treatment. All respondents were asked the year of their last visit to an eye practitioner.Results: A total of 3184 (89%) eligible residents were assessed. Sex (females), age (younger people), higher levels of education (secondary, trade, or tertiary education), recent visit to an eye practitioner (within the past 2 years) and English spoken at home appeared to be significant predictors of knowledge of common age related eye conditions. Younger people believed blindness prevention and blindness treatment were the highest priorities compared with other diseases; people who spoke English at home and people with knowledge of common age related eye disease also considered blindness treatment to be the highest priority compared with other diseases. People with a previous diagnosis of age related eye disease, older people, females, people with correct knowledge of common eye diseases, and those who spoke English at home were significantly more likely to be under eye care. No interaction was found between knowledge and positive attitudes to self care practices.Conclusion: These data show that here is a large gap in the public's knowledge and understanding of eye disease that will need to be understood for e
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ItemSelf-reported diabetes and distribution of HbA in a population-based sample in Victoria(Austrlasian Medical Publishing, 1999-03)As part of the Visual Impairment Project, a population-based study of eye disease, we have studied the self-reported prevalence of diabetes mellitus in a random sample of Victorians aged 40 years and older, and examined the distribution of haemoglobin A1c (HbA1c) in participants from rural areas.
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ItemOzone depletion: the ocular effects of UV-B exposure(Cancer Council Australia, 1996)Cataract is the most important eye disease associated with increased ocular exposure to UV-B. Biochemical and experimental evidence clearly links the development of cataract to UV-B exposure. Because of the difficulties in ascertaining individual ocular UV-B exposure over a lifetime, epidemiologic data have been much more limited. However; a number of epidemiologic studies have shown a consistent association between excess UV-B exposure and cortical cataracts, one of the major types of age-related cataract. These data provide the basis to recommend avoidance of unnecessary exposure of the eye to UV-B radiation, whether by avoiding outdoor activities in the middle of the day, or by protecting the eye by wearing a hat and/or UV-B absorbing eye glasses.
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ItemVisual impairment and socioeconomic factors( 1997)Background - Information about socio-economic factors associated with visual impairment can assist in the design of intervention programmes. Such information was collected by the Melbourne Visual Impairment Project (Melbourne VIP). Methods - The Melbourne VIP was a population based study of non-institutionalised permanent residents in nine suburbs of the Melbourne metropolitan area aged 40 years of age or older. A standardised eye examination was provided to eligible residents which included a structured interview. Variables of interest for this analysis were age, sex, country of birth, language spoken at home, education level, use of private health insurance, employment status, and living arrangements. Visual impairment was defined as a best corrected visual acuity < 6/18 and/or visual field constriction to within 20o of fixation. Results - A total of 3271 (83%) residents participated. Participants ranged in age from 40 to 98 years; 54% were female. Forty-four (1.34%) were classified as visually impaired due to visual acuity and/or visual field loss. To evaluate the independent association of the significant socio-demographic variables with visual impairment, a regression model was constructed that included age, retirement status, use of private health insurance, and household arrangement. The results showed that age was the significant predictor of visual impairment (OR: 3.19; CI: 2.29-4.43), with the mean age of people with visual impairment significantly older (75.0 years) compared with people without visual impairment (58.2 years) (t test=9.71; p=0.0001). Of the 44 visually impaired people, 39 (87%) were aged 60 years of age and older. Conclusion - The results indicate that age is the most significant factor associated with visual impairment. Of some importance was the finding that people with visual impairment were less likely to have private health insurance. With the aging of the population, the number of people affected by visual impairment will increase significantly. Intervention programmes need to be established before the onset of middle age to offset the escalation of visual impairment in the older population.
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ItemUse of eye care services by people with diabetes: the Melbourne Visual Impairment Project( 1998)Aim - The use of eye care services by people with and without diabetes was investigated in the Melbourne Visual Impairment Project (VIP), a population based study of eye disease in a representative sample of Melbourne residents over 40 years of age and older.Methods - A comprehensive interview was employed to elicit information on history of diabetes, medication use, most recent visit to an ophthalmologist and optometrist, and basic demographic details. Presence and extent of diabetic retinopathy was determined by dilated fundus examination.Results - The Melbourne VIP comprised 3271 people who ranged in age from 40 to 98 years; 46.2% of them were male. Of 3189 people who had the fundus examination and knew their diabetes status, 162 (5.1%) reported having been previously diagnosed with diabetes and, of these, 37 (22.2%) were found to have diabetic retinopathy. Seven people (4.3%) had developed diabetes before age 30. The mean duration of diabetes was 9.2 years. People with diabetes were significantly more likely to have visited an ophthalmologist over or in the past 2 years than people without diabetes. However, 31.8% of people with diabetes had never visited an ophthalmologist. The proportion of people who had never seen an ophthalmologist was 47.1% for people without diabetes, 34.2% for people with diabetes but without diabetic retinopathy, and 25% for people with diabetic retinopathy. Sixty one per cent of people with diabetic retinopathy had seen an ophthalmologist in the past year and a further 3% within the past 2 years. People with diabetes were not significantly more likely to have visited an optometrist than people without diabetes (p=0.51). Overall, 37.7% of people with diabetes and 32.9% of people without diabetes had visited an optometrist within the past year (%2=2.25, 1 df, p=0.13). Information concerning retinal examinations was available for 135 individuals (83.3% of people with diabetes). Only 74 (54.8%) could recall ever having a dil
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ItemThe need for cataract surgery: projections based on lens opacity, visual acuity, and personal concern( 1999)Aim - To assess the projected needs for cataract surgery by lens opacity, visual acuity, and patient concern. Methods - Data were collected as part of the Melbourne Visual Impairment Project, a population based study of age related eye disease in a representative sample of Melbourne residents aged 40 and over. Participants were recruited by a household census and invited to attend a local screening centre. At the study sites, the following data were collected: presenting and best corrected visual acuity, visual fields, intraocular pressure, satisfaction with current vision, personal health history and habits, and a standardised eye examination and photography of the lens and fundus. Lens photographs were graded twice and adjudicated to document lens opacities. Cataract was defined as nuclear greater than or equal to standard 2, 4/16 or greater cortical opacity, or any posterior subscapsular opacities. Results: 3271 (83% response) people living in their own homes were examined. The participants ranged in age from 40 to 98 years and 1511 (46.2%) were men. Previous cataract surgery had been performed in 107 (3.4%) of the participants. The overall prevalence of any type of cataract that had not been surgically corrected was 18%. If the presence of cataract as defined was considered the sole criterion for cataract surgery with no reference to visual acuity, There would be 309 cataract operations per 1000 people aged 40 and over (96 eyes of people who were not satisfied with their vision, 210 eyes of people who were satisfied with their vision, and three previous cataract operations). At a visual acuity criterion of less than 6/12 (the vision required to legally drive a car), 48 cataract operations per 1000 would occur and people would be twice as likely to report dissatisfaction with their vision. Conclusions - Estimates of the need for cataract surgery vary dramatically by level of lens opacity, visual acuity, and patient concern. These data should be useful for the planning of health services.
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ItemOcular exposure to UV-B in sunlight: the Melbourne visual impairmant project model( 1996)Quantification of ocular exposure to ultraviolet-B radiation (UV-B) has become an important public health issue, with reports that the ozone layer is being depleted worldwide. Ocular exposure to UV-B is determined by ambient UV-B levels, the duration of outdoor exposure, the proportion of ambient UV-B that reaches the eye, and the use of ocular protection. We have developed a simplified model for quantifying lifetime ocular UV-B exposure that can be used in large epidemiological surveys. Exposure to UV-B is assessed and quanified using a model based on personal exposure over the six summer months. Data available for a population-based sample of 1150 people in the age range 40-98 years revealed a distribution in average annual lifetime ocular VU-B exposure similar to that reported in a previous study on which this model is based, and also demonstrate that people can recall lifetime personal behaviour related to ocular protection. It takes 12 minutes on average to collect these data. This model can be employed by researchers worldwide for uniform assessment of ocular UV-B exposure.