Papers by Peggy PC Chiang
Clinical & Experimental Ophthalmology, 2016
Australian family physician, 2014
Diagnosing cancer on the basis of a patient's symptoms and risk factors is a core role for ge... more Diagnosing cancer on the basis of a patient's symptoms and risk factors is a core role for general practice. Equally, as part of a cost-effective health system, GPs should avoid over-investigation or referral of patients who are very unlikely to have cancer. Diagnosing cancer in primary care is not straightforward because many of the symptoms of cancer have more common benign causes. The aim of this article is to review the use of risk tools for diagnosing cancer in primary care. Certain cancers, such as lung, pancreas, ovary and myeloma, are particularly challenging to diagnose early. National guidelines exist to support identification of patients who are more likely to have an undiagnosed cancer but these list single symptoms as so-called 'red flags'. Validated risk tools, developed in general practice, exist that predict cancer diagnosis on the basis of patterns of symptoms and risk factors. These tools might prove useful in supporting cancer diagnosis in general prac...
Community eye health / International Centre for Eye Health, 2012
colleagues about any changes in the needs and vision-related abilities of the person with low vis... more colleagues about any changes in the needs and vision-related abilities of the person with low vision.
ABSTRACT PurposeThe current blindness and visual impairment definitions do not reflect the needs ... more ABSTRACT PurposeThe current blindness and visual impairment definitions do not reflect the needs for functional low vision (FLV) service and annual (or more frequent) eye evaluation (AEE) in the general population. We describe the prevalence of, causes of, and needs for FLV and AEE services in adult Indians and Malays living in Singapore. MethodsData were derived from two recent population-based, cross-sectional studies in Malays and Indians aged [≥] 40 years residing in Singapore. Visual impairment (VI) was defined as best-corrected visual acuity (BCVA) <6/18. FLV was defined as BCVA <6/18 in the better eye, after excluding those with no light perception in both eyes and those with treatable causes (e.g., cataract). People who need AEE were defined as those who had no VI in both eyes, but had diabetes, glaucoma, were glaucoma suspects (aged [≥]65 years, coupled with any glaucoma risk factor such as intraocular pressure >21mmHg or narrow angle), and/or had major retinal diseases (e.g., age-related macular
Pathologic Myopia, 2013
Pathologic myopia, sometimes referred as ‘malignant myopia’ or ‘degenerative myopia’, is a major ... more Pathologic myopia, sometimes referred as ‘malignant myopia’ or ‘degenerative myopia’, is a major growing public health problem worldwide. This chapter discusses the critical public health impact of pathologic myopia and its related ocular complications, such as glaucoma, cataract and retinal and macular changes. Specifically, the chapter elucidates the current epidemiological impact of pathologic myopia. The condition is one of the leading causes of blindness worldwide and its prevalence is rising. The condition also negatively impacts on patients’ quality of life, particularly vision-related activity limitation. Though data are scarce and further research is required on the true financial impact of the disease on patients and society, data extrapolation and estimates indicate that the direct and indirect economic impact is substantial. This chapter describes how pathologic myopia is shaped by the social determinants of health. The social determinants of health in turn produce comprehensive understanding of the disease pattern and concurrently identify who in the population are most affected or at high risk. Whilst the exact pathogenesis of pathologic myopia is still being unravelled by scientists and clinicians, this chapter proposes strategic ways which potentially could minimise the impact of pathologic myopia on public health.
Ophthalmology, 2015
Objective: To examine the impact of glaucoma and visual acuity (VA) and visual field (VF) losses ... more Objective: To examine the impact of glaucoma and visual acuity (VA) and visual field (VF) losses on psychosocial functioning (PF). Design: Cross-sectional study. Participants: We compared PF between 192 participants with bilateral glaucoma with VA or VF losses and 40 controls from a tertiary eye hospital clinic in Singapore. Methods: Glaucoma was defined using the Hodapp-Anderson-Parish criteria. Four psychosocial outcomes of the Glaucoma Quality of Life 36 questionnaire were psychometrically assessed using Rasch analysis. Multivariate regression was performed to determine the independent impact of glaucoma and VA and VF losses on PF. The impact of VA and VF on PF were evaluated by restricted cubic spline analysis. Main Outcome Measures: Anxiety, self-image, psychological well-being, and confidence in health care. Results: The mean age of participants was 66.2AE11.0 years, and 63% were male. In the better eye, VA and mean deviation were Snellen 20/25 and À8.89AE6.52 dB, respectively. In multivariate models, glaucoma patients had 63.0% greater anxiety (95% confidence interval [CI], À66.0% to À61.2%; P < 0.001), 71.0% lower self-image (95% CI, À74.1% to À68.5%; P < 0.001), 38.3% less psychological well-being (95% CI, À37.4% to À39.0%; P < 0.001), and 32.4% reduced confidence in health care than patients without glaucoma. The worst VA and VF categories had the most reduced PF (range, 26.0% to 81.5%; P < 0.001 for all associations) compared with controls. With worsening VA, there was a linear increase in anxiety (P ¼ 0.009) and decrease in self-image (P ¼ 0.005). With worsening VF from 0 to À12.1 dB (P ¼ 0.003), anxiety increased before plateauing. Self-image decreased as VF worsened from 0 to À10 dB (P < 0.001), and confidence in health care decreased when VF worsened from 0 to À9.3 dB (P ¼ 0.008). However, self-image and confidence in health care actually improved at greater levels of VF loss beyond these thresholds. Conclusion: Glaucoma negatively affects PF. Early stage glaucoma with mild VF loss adversely affects anxiety, self-image, and confidence in health care. As VA worsens in advanced glaucoma, anxiety further increases and self-image deteriorates. Ophthalmologists and glaucoma patients need to be aware that both VA and VF losses at different stages of glaucoma negatively impact PF. Ophthalmology 2015;122:494-501 ª 2015 by the American Academy of Ophthalmology.
Optometry and Vision Science, 2013
To describe the ethnic variations in the prevalence and risk factors for undercorrected refractiv... more To describe the ethnic variations in the prevalence and risk factors for undercorrected refractive error and its impact on vision-specific functioning (VF) in a multiethnic Asian population. A total of 3353 Chinese, 3400 Indians, and 3280 Malays in Singapore participated in this population-based cross-sectional study. Distance presenting visual acuity (VA) was measured using a logarithm of the minimum angle of resolution number chart. Best-corrected VA was assessed using the same test protocol as presenting VA. Undercorrected refractive error was defined as an improvement of at least 0.2 logarithm of the minimum angle of resolution (two lines equivalent) in the best-corrected VA compared with the presenting VA in the better eye when presenting VA was less than 20/40 in the better eye. The VF-11 questionnaire measured participants&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; VF. Multivariate linear regression was performed to assess the impact of undercorrected refractive error on the overall VF score. Regardless of ethnicity, participants with undercorrected refractive error had a reduction in VF score compared to those with normal vision in both eyes. The overall prevalence of undercorrected refractive error was highest in Indians (25.1%), followed by Malays (22.2%) and Chinese (19.7%). Undercorrected refractive error was less common in spectacles or contact lenses wearers than in non-spectacle wearers or non-contact lenses wearers. Adults with mild to moderate refractive errors were most likely to have undercorrected refractive error (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). In multivariate analysis, increasing age (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), Indian race (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), lower education level (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) or poorer housing (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), having refractive errors (p…
Ophthalmology, 2013
To quantify the eye disease-specific impact of unilateral and bilateral vision impairment (VI) on... more To quantify the eye disease-specific impact of unilateral and bilateral vision impairment (VI) on vision-specific functioning (VF). Design: The Singapore Indian Eye population-based study. Participants: Ethnic Indians older than 40 years of age living in Singapore. Methods: Participants underwent standardized ophthalmic assessments for VI and blindness, defined using presenting visual acuity (United States definition). Sociodemographic data were recorded using a standardized questionnaire. Rasch analysis was used to validate the Visual Function Index 11 and to determine its psychometric properties. The major causes of VI (i.e., cataract, refractive error, age-related macular degeneration, diabetic retinopathy [DR], and glaucoma) were determined by ophthalmologists on examination. Multivariate linear regression analysis was performed to assess the impact of VI on the overall VF Rasch score. Main Outcome Measures: Vision-specific functioning. Results: Three thousand three hundred ninety-six persons were analyzed. Participants with VI had a systematic reduction in VF score compared with those with normal vision in both eyes, ranging from Ϫ11.2% normal vision in one eye and low vision in the other eye (95% confidence interval [CI], Ϫ12.2% to Ϫ10.3%; PϽ0.001), to Ϫ12.7% blindness in one eye and normal vision in the other eye (CI, Ϫ15.1% to Ϫ10.4%; PϽ0.001), to Ϫ19.4% low vision in both eyes (CI, Ϫ20.8% to Ϫ18.1%; PϽ0.001), to Ϫ52.9% blindness in one eye and low vision in other eye (CI, Ϫ55.3% to Ϫ50.4%; PϽ0.001), to Ϫ77.2% blindness in both eyes (CI, Ϫ82.4% to 72.0%; PϽ0.001). The impact of VI on VF score varied across different major causes of vision loss, regardless of socioeconomic factors. Vision impairment attributed to cataract in one or both eyes had a significant decrease in VF score by 17.7% and 22.3%, respectively, compared with those with normal vision in both eyes (PϽ0.001). The impact of unilateral and bilateral VI on VF score was greater in participants with glaucoma (32.2% in unilateral cases and 35.9% in bilateral cases; PϽ0.001) and DR (29.4% in unilateral cases and 33.3% in bilateral cases; PϽ0.001). Conclusions: Vision impairment and major age-related eye diseases such as cataract, DR, and glaucoma are associated significantly with worse deterioration in VF, regardless of education level, literacy adequacy, or immigration pattern. Glaucoma and DR seemed to have a greater negative impact on VF score compared with cataract. This study highlights the importance of disease-specific interventions in reducing the adverse impact of VI on daily activities.
Ophthalmic Epidemiology, 2011
To conduct a global survey of low vision services to describe the needs, priorities, and barriers... more To conduct a global survey of low vision services to describe the needs, priorities, and barriers in provision and coverage. Data were mainly derived from a survey and from some secondary sources. The survey was distributed to Vision 2020 contacts, government, and non-government organizations (NGOs) in 195 countries during 2006-2008. Themes in the survey were: epidemiology of low vision, policies on low vision, provision of services, human resources, barriers to service delivery, equipment availability, and monitoring and evaluation of service outcomes. Contradictory and/or incomplete data were returned for further clarification and verification. The Human Poverty Index was used to compare the findings from developed and developing countries. Service availability was established for 178/195 countries, with 115 having some low vision service. Approximately half the countries in the African and Western Pacific regions have no services. Few countries have &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;10 low vision health professionals per 10 million of population. In many of the countries NGOs were the main providers and funders. Funding and awareness were frequently cited as barriers to service access. Women, people with disabilities, and rural dwellers were less likely to access services. There were few reports of monitoring and evaluation into the quality and impact of services. This global survey provides the first consolidated baseline of low vision service provision. Where data are available, coverage of services is generally poor. Low vision health professional numbers are low. Services in over half of the world&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s countries are funded by NGOs, raising issues of sustainability.
Ophthalmic Epidemiology, 2013
Awareness of eye conditions aids health promotion activities and leads to better outcomes. We exa... more Awareness of eye conditions aids health promotion activities and leads to better outcomes. We examined factors influencing the lack of awareness of common eye conditions in a population. The Singapore Malay Eye Study examined 3280 (78.7% response) Malays aged 40-80 years. We included 2112 (64.4%) participants with at least one of five eye conditions: 1504 (71.2%) with cataract, 1013 (47.8%) with myopia, 270 (12.8%) with diabetic retinopathy, 181 (8.6%) with age-related macular degeneration and 150 (7.1%) with glaucoma. Lack of awareness was defined in the questionnaire as not answering &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;yes&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; to previously being told by a doctor of having the eye condition. Among 2112 participants, 83.2% were unaware of at least one of their eye conditions. After controlling for age, sex and socioeconomic factors, participants unaware of their eye condition were older (odds ratio, OR, 1.03, per 1 year, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), had better visual acuity (OR 1.32, p = 0.04), lower education (OR 1.89, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), poorer literacy (OR 1.44, p = 0.02), lower income (OR 1.73, p = 0.009), higher blood glucose (OR 1.08, per 1 mmol/L, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), higher serum cholesterol (OR 1.20, per 1 mmol/L, p = 0.003), lower annual eye examination attendance (OR 2.08, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and were less likely to wear glasses (OR 2.90, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) than those who were aware of their condition. In this community-based population, 80% of those with common eye conditions were unaware of their condition.
Journal of Public Health, 2013
Background To examine whether marital status is a significant determinant of visual impairment (V... more Background To examine whether marital status is a significant determinant of visual impairment (VI) in urban multi-ethnic Asian population. Methods We conducted a population-based study of Singapore-resident ethnic Malays, Indians and Chinese aged 40 years. Ophthalmic examination included the assessment of presenting and best-corrected visual acuity (PVA and BCVA) using standardized procedures. Information regarding marital status and socioeconomic status were obtained from an interviewer-administered questionnaire. Results Among the 10 033 participants, 7756 (77.3%) were married; 589 (5.9%) were single; 407 (4.1%) were separated and 1265 (12.6%) were widowed. Being single (never married) or widowed were significantly associated with best-corrected VI (BCVA , 20/40) and presenting VI (PVA , 20/40) (odds ratios: 1.37-1.59) compared with married people even after adjustment for age, sex and socioeconomic status. A marginal prediction model showed that the negative effect of unmarried status on VI increased with age and was stronger among Malays and Indians, but the influence did not vary with gender, educational level and diabetic status. Conclusions Unmarried status is associated with VI, particularly among elderly Malays and Indians. Our findings suggest that single and widowed adults may benefit from specific social support and eye care programmes.
Investigative Opthalmology & Visual Science, 2011
PURPOSE. People with limited literacy are at increased risks of chronic systemic conditions. The ... more PURPOSE. People with limited literacy are at increased risks of chronic systemic conditions. The authors therefore investigated the independent contribution of limited literacy on visual impairment and visual function in a large eye survey in Singapore. METHODS. The authors undertook a population-based, crosssectional study of Asian Malays (Ն40 years old). Visual impairment was defined as logMAR (logarithm of minimal angle of resolution) visual acuity Ͼ 0.30 in the better-seeing eye. Information regarding reading and writing literacy levels and other independent variables, including sociodemographic measures (e.g., education, income), were obtained from a standardized interview. Visual functioning was assessed using a modified and validated version of the Vision-Specific Functioning Scale using Rasch analysis. RESULTS. Of the 3280 participants, 553 (16.9%) had inadequate reading literacy and 688 (21.0%) had inadequate writing literacy. In multivariate analysis, persons with inadequate reading literacy were more likely to have presenting visual impairment (odds ratio [OR] ϭ 2.66; 95% confidence interval [CI] ϭ 1.91 to 3.72; P Ͻ 0.001), best-corrected visual impairment (OR ϭ 2.59; 95% CI ϭ 1.70 to 3.96; P Ͻ 0.001), and poorer visual functioning ( coefficient ϭ 0.58; 95% CI ϭ 1.57 to 3.02; P Ͻ 0.001), even controlling for education, income, and other patients' characteristics. Similar associations were found for inadequate writing literacy. CONCLUSIONS. Inadequate literacy is independently associated with visual impairment and poorer visual functioning. Interventions that address literacy may help to reduce socioeconomic disparities in visual impairment.
Investigative Opthalmology & Visual Science, 2013
PURPOSE. We determined the impact of glaucoma severity and laterality on vision-specific function... more PURPOSE. We determined the impact of glaucoma severity and laterality on vision-specific functioning (VF) in an Asian population. METHODS. The Singapore Malay Eye Study (SiMES) was a population-based cross-sectional study of 3280 Malays aged 40 to 80 years. VF was assessed using the VF-11 questionnaire. Associations between VF-11 score and glaucoma clinical indices (glaucoma severity in better and worse eyes, and laterality) were determined by multivariate regression modeling. Glaucoma severity was defined as mild, moderate, advanced, and severe based on the Hodapp-Anderson-Parish system. Rasch analysis was used to validate the VF-11 and determine its psychometric properties. RESULTS. Of 926 persons analyzed, 123 had glaucoma (13.3% glaucoma prevalence in analyzed sample). The mean 6 SD VF score was 3.64 6 1.05 log of odds units (Logits). In multivariate models adjusting for sociodemographic, ocular, and systemic variables, poorer VF was associated with increasingly worse eye visual field loss (b ¼ 0.016, 95% confidence interval [CI] 0.004-0.029, P < 0.001), but not that of the better eye (P > 0.05). Compared to controls, VF was reduced in individuals with worse eye advanced and severe glaucoma (b ¼À0.65, 95% CI À1.03 to À0.28, P < 0.05), but not mild or moderate glaucoma (P > 0.05). Compared to controls, VF was reduced in unilateral (b ¼À0.29, 95% CI À0.54 to À0.04, P < 0.05), but not bilateral glaucoma (P > 0.05). These associations remained significant after adjusting for presenting and best-corrected visual acuity. CONCLUSIONS. Among Singaporean Malays, unilateral, and advanced and severe glaucoma in the worse eye significantly impacts on VF. Identifying early-stage glaucoma, preventing progression, and visual rehabilitation in advanced glaucoma are important aspects of glaucoma management.
Investigative Opthalmology & Visual Science, 2012
PURPOSE. We investigated patients' attitudes and perceptions toward a subconjunctival implant as ... more PURPOSE. We investigated patients' attitudes and perceptions toward a subconjunctival implant as a novel ocular drug delivery method for glaucoma. MATERIALS AND METHODS Study Design Our study was a cross-sectional study of patients receiving ophthalmic care at the Singapore National Eye Centre, a tertiary public healthcare From the
Investigative Opthalmology & Visual Science, 2011
PURPOSE. To validate the German-translated Impact of Vision Impairment (IVI) questionnaire, a vis... more PURPOSE. To validate the German-translated Impact of Vision Impairment (IVI) questionnaire, a vision-specific quality of life (QoL) scale, and determine the relationship between the severity of vision impairment, ocular conditions, and VRQoL. METHODS. This cross-sectional study was clinic based, with 184 patients with low vision recruited from an outpatient clinic at a German eye hospital. Participants underwent a clinical examination and completed the German IVI scale. The validity of the IVI scale was assessed using Rasch analysis. The main outcome measure was the overall functional and emotional score provided by the IVI. RESULTS. Overall, there were more female (n ϭ 111, 60.3%) than male participants. Participants' mean Ϯ SD age and visual acuity in the better eye were 69.0 Ϯ 15.5 years and. 0.41 Ϯ 0.35 logMAR, respectively. The main cause of vision loss was age-related macular degeneration (n ϭ 54, 29.3%). Rasch analysis demonstrated the validity of the German IVI to assess VRQoL through two subscales: vision-specific functioning and emotional well-being. In adjusted multivariate analysis models, those with mild or moderate/severe vision impairment reported significantly poorer vision-specific functioning (mean change, Ϫ6.5, P ϭ 0.018 and Ϫ11.98, P Ͻ 0.001 for mild and moderate to severe VI, respectively) and emotional well-being (mean change, Ϫ2.35; P ϭ 0.043 and Ϫ3.13, P ϭ 0.004 for mild and moderate/severe VI respectively) compared with non-visually impaired patients. CONCLUSIONS. Using a psychometrically valid German IVI, even mild vision impairment was independently associated with poor VRQoL. These findings reinforce the importance of early preventative and rehabilitative efforts to prevent longitudinal deterioration in vision loss.
Investigative Opthalmology & Visual Science, 2011
PURPOSE. To evaluate the validity, reliability, and measurement characteristics of the Visual Fun... more PURPOSE. To evaluate the validity, reliability, and measurement characteristics of the Visual Function 14 (VF-14) in a German sample using Rasch analysis. METHODS. This was a clinic-based, cross-sectional study with 184 patients with low vision recruited from an outpatient clinic at a German eye hospital. Participants underwent a clinical examination and completed the German VF-14 scale. The validity of the VF-14 scale was assessed using Rasch analysis. The main outcome measure was the overall functional score provided by the VF-14. RESULTS. After collapsing two response categories for items 13 and 14, the VF-14 scale satisfied fundamental criteria to achieve fit to the Rasch model, namely, ordered thresholds, the ability to distinguish between different strata of participant ability, absence of misfitting items, no evidence of unidimensionality, and no significant differential item functioning for key sociodemographic covariates. The VF-14 is able to discriminate between participants with different levels of vision impairment and across different cultural groups. CONCLUSIONS. The VF-14 is a valid, reliable, and unidimensional questionnaire for use in a German population. These findings contribute to the growing evidence base for second generation patient reported outcome measures in ophthalmology, and support the use of the German VF-14 in tertiary eye clinics in Germany to capture the impact of visual impairment on visual function from the patient's perspective and to inform low vision rehabilitation and interventions.
Indian Journal of Ophthalmology, 2012
Two-thirds of the world's population with low vision resides in the Asia-Pacific region. Provisio... more Two-thirds of the world's population with low vision resides in the Asia-Pacific region. Provision of comprehensive low vision services is important to improve vision-related quality of life (QoL) for people with this condition. This review outlines the critical issues and challenges facing the provision of low vision services in the Asia-Pacific region. The review offers possible strategies to tackle these issues and challenges facing service providers and policy makers in lieu of Vision 2020 strategies in this area. Pertinent findings from the global survey of low vision services and extensive ground work conducted in the region are used; in addition, a discussion on the availability of services, human resources and training, and funding and the future sustainability of low vision care will be covered. In summary, current issues and challenges facing the region are the lack of specific evidence-based data, access, appropriate equipment and facilities, human resources, funding, and sustainability. These issues are inextricably interlinked and thus cannot be addressed in isolation. The solutions proposed cover all areas of the VISION 2020 strategy that include service delivery, human resources, infrastructure and equipment, advocacy and partnership; and include provision of comprehensive care via vertical and horizontal integration; strengthening primary level care in the community; providing formal and informal training to enable task shifting and capacity building; and promoting strong government and private sector partnership to achieve long-term service financial sustainability.
Graefe's Archive for Clinical and Experimental Ophthalmology, 2011
To validate the German-translated VF-14, a vision-specific scale, and determine the relationship ... more To validate the German-translated VF-14, a vision-specific scale, and determine the relationship between the severity of vision impairment, ocular conditions, and visual functioning. This was a clinic-based, cross-sectional study with 184 patients with low vision and 90 normal-sighted controls recruited from a German eye hospital. Participants underwent a clinical examination and completed the German VF-14 scale. The validity of the VF-14 scale was assessed using Rasch analysis. The main outcome measure was the visual functioning overall score. The participants&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; mean ± SD [standard deviation] age was 59.4 ± 21.8 years ,and there were more female (58.4%) than male participants. The main cause of vision loss was age-related macular degeneration [AMD] (n = 54, 19.7%). Rasch analysis substantiated the German VF-14 to be a valid scale to assess visual functioning in the sample. Visual functioning consistently declined with worsening vision. In adjusted-multivariate analysis models, compared to control participants, those with mild, or moderate/severe vision impairment recorded significantly poorer visual functioning scores (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). The independent association was clinically significant for those with moderate/severe vision impairment. The main ocular conditions were also found to be independently associated with worse visual functioning, with clinical significance found for AMD, diabetic retinopathy, and other retinal diseases. Using a psychometrically valid German-translated VF-14, even mild vision impairment was independently associated with poor visual functioning. These findings reinforce the importance of early preventative and rehabilitative efforts to prevent longitudinal deterioration in vision loss.
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