The impact of knowledge and attitudes on access to eye-care services in Cambodia

Purpose: To investigate how knowledge and attitudes influence the access to eye-care services in Takeo Province, Cambodia.

Design: A cross-sectional survey (n=600).

Methods: 30 villages were randomly selected. Groups included: >50 years, 30–49 years, and parents with children <5 years. A newly developed Knowledge, Attitude and Practice in Eye Health (KAP-EH) questionnaire about knowledge and treatment of eye diseases, practices and attitudes to accessing services was used to interview respondents. Descriptive analysis, including Chi square and logistic regression tested for associations with sub-groups of gender, age group, education and self-reported type of disability.

Results: The proportion of respondents who reported having knowledge of specific eye conditions ranged from 97% for eye injury, to 8% for diabetic eye disease. While 509 (85%) people reported knowledge of cataract, 47% did not know how cataract was treated and only 19% listed surgery. The older group (66.5%) were least informed about cataract (p= 0.001) compared to other groups, and were least likely to believe that some blindness could be prevented (p < 0.001). Women (55%) were more likely than men (46%) (p=0 .003) to report that a child with blindness could attend school, as did people without a disability compared to those with a disability (58% vs 34%) (p < 0.001).

Conclusions: The knowledge about cataract and refractive error and what to do to resolve the problems was low among this population and this study suggests that poor knowledge of eye diseases might contribute to the occurrence of un-operated cataract and uncorrected refractive error.

Expression of muscarinic receptor subtypes in tree shrew ocular tissues and their regulation during the development of myopia

Muscarinic receptors are known to regulate several important physiologic processes in the eye. Antagonists to these receptors such as atropine and pirenzepine are effective at stopping the excessive ocular growth that results in myopia. However, their site of action is unknown. This study details ocular muscarinic subtype expression within a well documented model of eye growth and investigates their expression during early stages of myopia induction. Total RNA was isolated from tree shrew corneal, iris/ciliary body, retinal, choroidal, and scleral tissue samples and was reverse transcribed. Using tree shrew-specific primers to the five muscarinic acetylcholine receptor subtypes (CHRM1-CHRM5), products were amplified using polymerase chain reaction (PCR) and their identity confirmed using automated sequencing. The expression of the receptor proteins (M1-M5) were also explored in the retina, choroid, and sclera using immunohistochemistry. Myopia was induced in the tree shrew for one or five days using monocular deprivation of pattern vision, and the expression of the receptor subtypes was assessed in the retina, choroid, and sclera using real-time PCR. All five muscarinic receptor subtypes were expressed in the iris/ciliary body, retina, choroid, and sclera while gene products corresponding to CHRM1, CHRM3, CHRM4, and CHRM5 were present in the corneal samples. The gene expression data were confirmed by immunohistochemistry with the M1-M5 proteins detected in the retina, choroid, and sclera. After one or five days of myopia development, muscarinic receptor gene expression remained unaltered in the retinal, choroidal, and scleral tissue samples. This study provides a comprehensive profile of muscarinic receptor gene and protein expression in tree shrew ocular tissues with all receptor subtypes found in tissues implicated in the control of eye growth. Despite the efficacy of muscarinic antagonists at inhibiting myopia development, the genes of the muscarinic receptor subtypes are neither regulated early in myopia (before measurable axial elongation) nor after significant structural change.

Simulated hyperopic anisometropia and reading, visual information processing, and reading-related eye movement performance in children.

Purpose: This study investigated the impact of simulated hyperopic anisometropia and sustained near work on performance of academic-related measures in children.
Methods: Participants included 16 children (mean age: 11.1 ± 0.8 years) with minimal refractive error. Academic-related outcome measures included a reading test (Neale Analysis of Reading Ability), visual information–processing tests (Coding and Symbol Search subtests from the Wechsler Intelligence Scale for Children), and a reading-related eye movement test (Developmental Eye Movement test). Performance was assessed with and without 0.75 diopters of simulated monocular hyperopic defocus (administered in a randomized order), before and after 20 minutes of sustained near work. Unilateral hyperopic defocus was systematically assigned to either the dominant or nondominant sighting eye to evaluate the impact of ocular dominance on any performance decrements.
Results: Simulated hyperopic anisometropia and sustained near work both independently reduced performance on all of the outcome measures (P < 0.001). A significant interaction was also observed between simulated anisometropia and near work (P < 0.05), with the greatest decrement in performance observed during simulated anisometropia in combination with sustained near work. Laterality of the refractive error simulation (ocular dominance) did not significantly influence the outcome measures (P > 0.05). A reduction of up to 12% in performance was observed across the range of academic-related measures following sustained near work undertaken during the anisometropic simulation.
Conclusions: Simulated hyperopic anisometropia significantly impaired academic-related performance, particularly in combination with sustained near work. The impact of uncorrected habitual anisometropia on academic-related performance in children requires further investigation. © 2014 The Association for Research in Vision and Ophthalmology, Inc.

Effect of retinal image defocus on the thickness of the human choroid

PURPOSE: To describe the time-course and amplitude of changes to sub-foveal choroidal thickness (SFCT) induced by imposed hyperopic and myopic retinal defocus and to compare the responses in emmetropic and myopic subjects. METHODS: Twelve East Asian subjects (age: 18-34 years; six were emmetropic and six had myopia between -2.00 and -5.00 dioptres (D)) viewed a distant target (video movie at 6 m) for 60 min on two separate occasions while optical coherence tomography (OCT) images of the choroid were taken in both eyes every 5 min to monitor SFCT. On each occasion, one eye was optimally corrected for distance with a contact lens while the other eye wore a contact lens imposing either 2.00 D hyperopic or 2.00 D myopic retinal defocus. RESULTS: Baseline SFCT in myopic eyes (mean ± S.D.): 256 ± 42 μm was significantly less than in emmetropic eyes (423 ± 62 μm; p < 0.01) and was correlated with magnitude of myopia (-39 μm per dioptre of myopia, R(2) = 0.67: p < 0.01). Repeated measures anova (General Linear Model) analysis revealed that in both subject groups, 2.00 D of myopic defocus caused a rapid increase in SFCT in the defocussed eye (significant by 10 min, increasing to approximately 20 μm within 60 min: p < 0.01), with little change in the control eye. In contrast, 2.00 D of hyperopic defocus caused a decrease in SFCT in the experimental eye (significant by 20-35 min. SFCT decreased by approximately 20 μm within 60 min: p < 0.01) with little change in the control eye. CONCLUSIONS: Small but significant changes in SFCT (5-8%) were caused by retinal defocus. SFCT increased within 10 min of exposure to 2.00 D of monocular myopic defocus, but decreased more slowly in response to 2.00 D of monocular hyperopic defocus. In our relatively small sample we could detect no difference in the magnitude of changes to SFCT caused by defocus in myopic eyes compared to emmetropic eyes.

Religious ambivalence: suppression of pro-social attitudes toward asylum seekers by right-wing authoritarianism

A survey of 168 White Australian community members examined whether ambivalence toward certain social groups by some religious individuals constituted a suppression effect in which authoritarian motivated prejudice suppressed more pro-social attitudes toward asylum seekers. Using mediation analysis, it was found that Christian religious identity was not significantly associated with prejudice at a bivariate level. However, when Right-Wing Authoritarianism (RWA) was taken into account, Christians (compared with non-Christians) were less likely to hold negative attitudes toward asylum seekers in Australia. Inclusion of acculturation ideologies (assimilation, multiculturalism, and color-blindness) in the models indicated that the suppression effect was specific to RWA rather than due to other intergroup attitudes. However, findings suggest that multiculturalism may be one proximal indicator of Christian pro-sociality.

Knowledge, attitudes, and self care practices associated with age related eye disease in Australia

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 there is a large gap in the public's knowledge and understanding of eye disease that will need to be understood for eye health promotion activities.

Use of eye care services by people with diabetes: the Melbourne Visual Impairment Project

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 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 ever 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 (chi 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 dilated fundus examination; 10 (14%) by an optometrist, 62 (86%) by an ophthalmologist, and five (7%) by a general practitioner. Of those 68 people who had seen an ophthalmologist in the past 2 years, 48 (71%) reported a dilated fundus examination during that time. This compares with 28 (43%) reported dilated fundus examinations in the 65 people who had seen an optometrist in the past 2 years. This finding is statistically significant (chi 2 = 10.2, 1 df, p < 0.005). CONCLUSION: These results indicate that nearly half of people with diabetes in Melbourne are not receiving adequate screening or follow up for diabetic retinopathy, despite universal health care.

Visual impairment and socioeconomic factors

BACKGROUND: Information about socioeconomic 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 and 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 20 degrees 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 sociodemographic 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.

Visual impairment in Australia: distance visual acuity, near vision, and visual field findings of the Melbourne Visual Impairment Project

PURPOSE: To describe the age-specific and gender-specific rates of blindness and visual impairment in urban adults aged 40 years and older. METHODS: A population-based sample of residents was recruited. Presenting and best-corrected distance visual acuities were assessed. Functional near vision was measured at each participant's preferred distance. Visual field examination was performed with a Humphrey Field Analyzer (HFA); those unable to perform the field analyzer test attempted a Bjerrum screen or confrontation field. RESULTS: The study population comprised 3,271 residents (83% of eligible) from ages 40 to 98 years; 54% were women. Overall, 56% of the study population wore distance correction; this was significantly lower in men but higher in the older age groups. Age-adjusted rates of blindness were 0.066% in men and 0.170% in women. Vision with current correction improved after refraction by gender and age. Direct age-standardized rates of functional near vision did not vary significantly by gender. Forty-six people had significant visual field loss in their better eye. The proportion of participants with constriction of the visual field to within 20 degrees of fixation was similar for men and women when controlled for age (odds ratio, 0.81; 95% confidence interval, 0.44 to 1.49) but increased significantly with age controlled for gender. Visual field abnormalities were detected in 548 right eyes (17%) and 533 left eyes (16%). CONCLUSIONS: Although overall rates of blindness because of visual acuity loss were relatively low, nearly three times more people had visual impairment because of visual field loss than visual acuity loss. These results highlight the need to target blindness prevention programs to the aging population, with a special emphasis on women.

The epidemiology of cataract: a review of the literature

Cataract is a major cause of blindness, accounting for nearly half of all blindness worldwide. Epidemiological research provides the principles and methods to assess the extent of cataract, and supplies the necessary information for policy planning. Obtaining accurate epidemiological data on cataract is essential to ascertain and estimate the cost of primary and secondary eye health care needs. Determining risk factors is also necessary to reduce the economic and social repercussions associated with the disease. The following paper presents a review of the epidemiology of cataract in the middle to elderly age group.

Knowledge of glaucoma, and its relationship to self-care practices, in a population sample

OBJECTIVE: To determine the level of knowledge of glaucoma in a population-based sample, and its relationship to self-care practices.

DESIGN AND SUBJECTS: A cluster random sample of the Melbourne population 40 years of age and older was interviewed. One thousand seven hundred and eleven residents living in five randomly selected Melbourne metropolitan suburbs, each consisting of two adjacent census collector districts.

MEASURES: Questions were asked concerning respondents' awareness, knowledge and description of the disease. Respondents were also asked the year of their last visit to their eye health care provider.

RESULTS: Seventy per cent of the sample had heard of glaucoma. However, only 22% provided a description that demonstrated a reasonable understanding of the disease. A lack of awareness and knowledge of glaucoma appeared to be negatively related to self-care practices.

CONCLUSION: Serious deficiencies in the basic knowledge of glaucoma in the community was demonstrated. This has significant public health implications as only a small percentage of the at-risk population may present themselves for assessment and treatment. Informing the community about glaucoma is an important step in promoting preventative ophthalmic care and reducing visual impairment and blindness.

The importance of epidemiology in understanding eye disease

Most leading causes of visual impairment are age related, so the health care implications of an increasing prevalence of eye disease in the elderly are significant. Epidemiological research provides the foundation to address immediate and long-term needs associated with visual impairment and eye disease. It contributes to a community's knowledge of the presence, diagnosis, characteristics, and distribution of eye conditions affecting the elderly. Obtaining accurate epidemiological information on the extent of visual impairment and eye disease in the community is essential to determine and estimate the cost of primary and secondary eye health care needs.

Identification, characterisation and expression analysis of natural killer receptor genes in chlamydia pecorum infected koalas (phascolarctos cinereus)

BACKGROUND: Koalas (Phascolarctos cinereus), an iconic Australian marsupial, are being heavily impacted by the spread of Chlamydia pecorum, an obligate intracellular bacterial pathogen. Koalas vary in their response to this pathogen, with some showing no symptoms, while others suffer severe symptoms leading to infertility, blindness or death. Little is known about the pathology of this disease and the immune response against it in this host. Studies have demonstrated that natural killer (NK) cells, key components of the innate immune system, are involved in the immune response to chlamydial infections in humans. These cells can directly lyse cells infected by intracellular pathogens and their ability to recognise these infected cells is mediated through NK receptors on their surface. These are encoded in two regions of the genome, the leukocyte receptor complex (LRC) and the natural killer complex (NKC). These two families evolve rapidly and different repertoires of genes, which have evolved by gene duplication, are seen in different species. METHODS: In this study we aimed to characterise genes belonging to the NK receptor clusters in the koala by searching available koala transcriptomes using a combination of search methods. We developed a qPCR assay to quantify relative expression of four genes, two encoded within the NK receptor cluster (CLEC1B, CLEC4E) and two known to play a role in NK response to Chalmydia in humans (NCR3, PRF1). RESULTS: We found that the NK receptor repertoire of the koala closely resembles that of the Tasmanian devil, with minimal genes in the NKC, but with lineage specific expansions in the LRC. Additional genes important for NK cell activity, NCR3 and PRF1, were also identified and characterised. In a preliminary study to investigate whether these genes are involved in the koala immune response to infection by its chlamydial pathogen, C. pecorum, we investigated the expression of four genes in koalas with active chlamydia infection, those with past infection and those without infection using qPCR. This analysis revealed that one of these four, CLEC4E, may be upregulated in response to chlamydia infection. CONCLUSION: We have characterised genes of the NKC and LRC in koalas and have discovered evidence that one of these genes may be upregulated in koalas with chlamydia, suggesting that these receptors may play a role in the immune response of koalas to chlamydia infection.