Visual impairment and socioeconomic factors

The Risk of Major Depressive Disorder Due to Cataracts among the Korean Elderly Population: Results from the Korea National Health and Nutrition Examination Survey (KNHANES) in 2016 and 2018

Cataracts and major depressive disorder (MDD) both have high prevalence, representing for major health burdens globally. In this study, we examined the risk of MDD due to cataracts. Data from the 2016 to 2018 Korea National Health and Nutrition Examination Survey (KNHANES) were used, including 4122 participants. Logistic regression analysis was performed to evaluate the odds ratio for MDD in association with cataracts. Controlled variables were age, gender, smoking, dyslipidemia and mobility. Subgroup analysis was performed with stratification by gender. The results reveal that cataracts are significantly correlated with MDD. Elderly people with cataracts were found to be more likely to develop MDD compared to those without cataracts (adjusted odds ratio: 1.654; 95% CI = 1.197-2.286). In subgroup analysis, men (adjusted odds ratio: 2.631; 95% CI = 1.247-5.551) were found to be more likely to develop MDD than women (adjusted odds ratio: 1.510; 95% CI = 1.061-2.150). Cataracts may be a risk factor for MDD in the elderly, especially among the male population.

Prevalence and Causes of Visual Impairment and Blindness in Elderly Population; an Urgent Geriatric Health Issue: Tehran Geriatric Eye Study (TGES)

PURPOSE

To determine the prevalence of vision impairment (VI) and blindness and their determinants in the elderly population of Tehran.

METHODS

In a cross-sectional study, multi-stage cluster sampling was used to select a sample of over 60 year population of Tehran. Optometric examinations included the measurement of uncorrected visual acuity, objective and subjective refraction, presenting and best corrected visual acuity. Vision impairment is reported according to the WHO definition. Visual acuity worse than 20/60 and 20/400 in the better eye was regarded as low vision and blindness, respectively.

RESULTS

According to presenting visual acuity, VI was found in 14.8% (95%CI: 13.1-16.5) of the participants, including low vision in 13.8% (95%CI: 12.2-15.4) and blindness in 1.1% (95%CI: 0.5-1.6). The prevalence of VI ranged between 7.8% (95%CI: 6.0-9.5) in subjects aged 60-64 years and 40.0% (95%CI: 33.0-47.0) in participants over 80 years (p < .001). Multivariable logistic regression analysis showed that older age (OR = 1.07(per year)), lower education level (illiterate versus college: OR = 3.55), and lower economic status (middle versus rich: OR = 1.30 and poor versus rich; OR = 1.72) had a significant relationship with an increase in the prevalence of VI, and older age (OR = 1.14(Per year increase)) and diabetes (OR = 2.62) had a significant relationship with blindness. Refractive errors (63.1%) was the leading cause of VI followed by cataract (22.5%). However, cataract (48.3%) was the leading cause of blindness.

CONCLUSION

Many older adults suffer from VI. Correction of refractive errors and cataract reduces a large percentage of VI. Age, education level, and economic status are other determinants of VI.

Association Between Tobacco Consumption and Self-Reported Visual Impairment in Adults of High-Altitude Andean Communities of Peru

To determine the association between tobacco consumption and self-reported visual impairment. We performed a cross-sectional study based on an original cohort study. A non-probabilistic sampling was performed to invite 413 patients of 60 years or more from 11 high-altitude Andean communities (altitude higher than 1500 m above sea level) of Peru between 2013 and 2017. Demographic data and information on tobacco consumption were collected. Associations were determined using a Poisson regression model with 95% confidence intervals (CI). Of the 413 participants, 141 (34.14%) were men and 49 (11.86%) were tobacco users. In the adjusted model, tobacco users presented a high probability of visual impairment with a prevalence ratio of 1.32 (95% CI: 1.18–1.97). We also found that having two or more comorbidities 2.19 (95% CI: 1.53–3.15), receiving health assistance in a pharmacy 3.75 (95% CI: 1.97–7.16), and coffee consumption 1.67 (95% CI: 1.26–2.21) were factors significantly associated with self-reported visual impairment. We determined that in Peruvian high-altitude Andean communities, visual impairment was more frequent in individuals reporting tobacco consumption, taking alternative medicine, going directly to a drug store without primary care physician consultation, having more than one comorbidity, and coffee consumption.

Socioeconomic and physical health status changes after visual impairment in Korea using difference-in-difference estimations

This study analyzed the impact of visual impairment on socioeconomic and physical health status and its heterogeneity by severity of visual impairment. We used nationally representative cohort data based on Korean national health insurance claims (2002–2013), which were extracted for 11,030 persons (2206 visually impaired, 8824 control). This was restructured as monthly data for each person (person-month). Multivariate and ordered logistic regressions were conducted, and the pre-impairment status between the visually impaired and non-visually impaired people was adjusted by difference-in-difference (DiD) estimation. Focusing on medical aid (a public healthcare service assistance program for people who cannot afford health insurance premiums), the DiD estimate showed that the likelihood of receiving aid was higher among visually impaired compared with non-impaired people. Mildly and severely visually impaired people were more likely to be medical aid recipients than their counterparts. The severely visually impaired group was more likely to be unemployed. The visually impaired group were less likely to have no comorbidity. Our findings show that the socioeconomic and physical health status of visually impaired people is more likely to deteriorate than that of their non-visually impaired counterparts following onset of impairment.

The Burden of Visual Impairment and Blindness from Vitreoretinal Diseases: A Nigerian Tertiary Hospital Retina Unit Experience

Objective:

The objective of this study is to determine the burden of visual impairment and blindness from vitreoretinal diseases in the retina unit of a Nigerian tertiary hospital.

Methodology:

A prospective, cross-sectional study on all consecutive new patients presenting with vitreoretinal diseases (VRD) at the vitreoretinal (VR) clinic at Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife from May 2011 to April 2014. Patient's bio-data, presenting complains, Snellen's or tumbling E-chart visual acuity unaided, slit-lamp examination of the vitreous and fundus with +90/+78D, binocular indirect ophthalmoscopy as well as slit-lamp examination of anterior segment, and applanation tonometry findings were recorded in predesigned pro forma. Visual acuity was categorized using WHO/ICD. The data were analyzed using the SPSS software version 16 for simple frequencies and presented.

Results:

Of 2025 eyes reviewed, 112 (49.8%) eyes were visually impaired and 67 (29.8%) were blind. Eight (5.2%) patients were bilaterally blind. Diabetic retinopathy was the most common cause of bilateral blindness (25%), and concurrently, the most common VRD (29.8%). All categories of visual loss were more prevalent among the aged ≥65 years. More males (62.2%) were blind from VRD. Cataract was the most common ocular comorbidity seen (43.6%).

Conclusion:

The burden of visual impairment and blindness from VRD is large; eye health education for early presentation for eye care as well as the development of VR care with infrastructure upscale to include optical coherence tomography, laser, and surgical care for prompt diagnosis and treatment will be of benefit in reducing the burden.

Visual impairment and associated factors among primary school children in Gurage Zone, Southern Ethiopia

Background

Visual impairment is one of the major public health problems worldwide, especially in developing countries.

Objective

To determine the prevalence of visual impairment and its associated factors among school children in Gurage Zone, Southern Ethiopia

Methods

A cross sectional study was conducted in eight primary schools of Gurage Zone. A total of 1064 pupils, of whom589 boys and 475 girls were selected using multistage sampling technique. Socio-demographic characteristics of the participants were collected using structured questionnaires and visual acuity was measured using Snellen's chart. Logistic regression analysis was used to determine the associated factors of visual impairment.

Results

The prevalence of visual impairment was 5.2%. Factors significantly associated with visual impairment were age group of 13–18 years (AOR = 9.44, 95% CI = 3.83 – 23.25), school grade level of 5- 8 (AOR = 2.97, 95% CI = 1.23 – 7.17), rural residents (AOR = 2.59, 95% CI = 1.22 – 5.54), family's monthly income of less than 2000 Ethiopian Birr (AOR = 2.87, 95% CI = 1.08 – 7.61) and visually impaired parents (AOR = 2.16, 95% CI = 1.06 – 4.39).

Conclusion

This study found that the prevalence of visual impairment was 5.2%.

Prevalence And Associated Factors Of Visual Impairment Among School-Age Children In Bahir Dar City, Northwest Ethiopia

INTRODUCTION

Visual impairment (VI) is one of the major public health problems in the world. It is highly prevalent among children in sub-Saharan countries, including Ethiopia. Worldwide, the magnitude of VI among school-age children is 1%-10%. However, there was limited information regarding the prevalence and associated factors of VI among school-age children in the study area, which is essential to plan and implement appropriate interventions.

OBJECTIVE

The aim of this study was to determine the prevalence and associated factors of VI among school-age children livin g in Bahir Dar city, northwest Ethiopia.

METHODS

A community-based cross-sectional study was done on a sample of 632 school-age children selected by multistage sampling in Bahir Dar from April 30 to May 15, 2018. Data were collected through interviews and physical examinations. Face-to-face interviews were done with a pretested semistructured questionnaire. Physical examinations were done with visual acuity measures and assessment of ocular pathology by optometrists. Data were entered into Epi Info 7 and exported to and analyzed with SPSS 20. Binary logistic regression was fitted, and variables with P<0.05 in the multivariate model were considered statistically significant.

RESULTS

A total of 601 study subjects were included in this study, giving a response rate of 95.2%. The median age was 13 (IQR 11-16) years, and 303 (50.3%) were male. Prevalence of VI was 52 (8.7%, 95% CI 6.2%-10.7%). In multivariate analysis, prematurity [AOR 2.8 (95% CI 1.19-6.83)], admission to a neonatal intensive-care unit (AOR 5.5, 95% CI 2.01-15.15), having a parent with VI (AOR 1.8, 95% CI 0.13-0.97), watching television from <2 m (AOR 8.7, 95% CI 1.49-18.24), and mobile-phone exposure >4 hours per day (AOR 1.6, 95% CI 1.32-4.45) were factors significantly associated with VI.

CONCLUSION

The prevalence of VI among school-age children in Bahir Dar was significant. Premature birth, admission to a neonatal intensive-care unit, having a parent with VI, watching television from <2 m, and mobile exposure >4 hours per day were significantly associated.

Multiple deprivation, vision loss, and ophthalmic disease in adults: global perspectives

The association between socioeconomic position and morbidity and mortality has long been recognized. We evaluate the evidence for an association between multiple aspects of deprivation and ocular health in a global context. This is a systematic review of studies that evaluated deprivation in the adult population in the context of the major acquired causes of visual loss such as cataract, diabetic eye disease, glaucoma, age-related macular degeneration, and ocular trauma. The search strategy identified relevant studies reported between 1946 and August 2016, with randomized control trials, case-control, cohort, and cross-sectional study designs being selected for inclusion. The studies identified in this review from across the world demonstrate the extent to which the common themes such as low educational attainment and low income may be associated with increased incidence of various sight-threatening conditions and may adversely affect access to specialist assessment and delivery of treatment. Health inequality may always persist, but an increased recognition of the importance of the various impacts of deprivation may empower policy makers to target limited resources to the most vulnerable groups in order to deliver the greatest benefit.

The Prevalence of Visual Acuity Impairment among School Children at Arada Subcity Primary Schools in Addis Ababa, Ethiopia

BACKGROUND

Visual impairment and blindness are major public health problems in developing countries where there is no enough health-care service.

OBJECTIVE

To determine the prevalence of visual impairment among school children.

MATERIALS AND METHODS

A school-based cross-sectional study was conducted between 15 June 2015 and 30 November 2015 at Arada subcity primary schools, Addis Ababa, Ethiopia. Two schools were selected randomly, and 378 students were screened from grades 1 to 8 using systematic random sampling method. Snellen chart was used for visual acuity test. Students who had visual acuity of ≤6/12 were further examined by an ophthalmologist to diagnose the reason for low vision. Data was analyzed using SPSS version 20.

RESULTS

A total of 378 students were screened, and 192 (50.8%) were females and the remaining 186 (49.2%) were males. The prevalence of visual impairment (VA) of ≤6/12 on either eye was 5.8%, VA < 6/18 on either eye was 1.1%, and VA < 6/18 on the better eye was 0.53%. In this study, color blindness [OR: 19.65, 95% CI (6.01-64.33)] was significantly associated with visual acuity impairment.

CONCLUSION

The prevalence of visual impairment among school children in the study area was 5.8% and school screening is recommended.

The prevalence of visual impairment and blindness in underserved rural areas: a crucial issue for future

PurposeTo determine the prevalence of visual impairment and blindness in underserved Iranian villages and to identify the most common cause of visual impairment and blindness.Patients and methodsMultistage cluster sampling was used to select the participants who were then invited to undergo complete examinations. Optometric examinations including visual acuity, and refraction were performed for all individuals. Ophthalmic examinations included slit-lamp biomicroscopy and ophthalmoscopy. Visual impairment was determined according to the definitions of the WHO and presenting vision.ResultsOf 3851 selected individuals, 3314 (86.5%) participated in the study. After using the exclusion criteria, the present report was prepared based on the data of 3095 participants. The mean age of the participants was 37.6±20.7 years (3-93 years). The prevalence of visual impairment and blindness was 6.43% (95% confidence interval (CI): 3.71-9.14) and 1.18% (95% CI: 0.56-1.79), respectively. The prevalence of visual impairment varied from 0.75% in participants aged less than 5 years to 38.36% in individuals above the age of 70 years. Uncorrected refractive errors and cataract were the first and second leading causes of visual impairment; moreover, cataract and refractive errors were responsible for 35.90 and 20.51% of the cases of blindness, respectively.ConclusionThe prevalence of visual impairment was markedly high in this study. Lack of access to health services was the main reason for the high prevalence of visual impairment in this study. Cataract and refractive errors are responsible for 80% of visual impairments which can be due to poverty in underserved villages.

Outdoor Air Pollution and Pterygium in Korea

We investigated relationships between outdoor air pollution and pterygium in Korean adults. This study includes 23,276 adults in population-based cross-sectional data using the Korea National Health and Nutrition Examination Survey 2008-2011. Pterygium was assessed using slit lamp biomicroscopy. Air pollution data (humidity, particulate matter with aerodynamic diameter less than 10 μm [PM₁₀], ozone [O₃], nitrogen dioxide [NO₂], and sulfur dioxide levels [SO₂]) for 2 years preceding the ocular examinations were acquired. Associations of multiple air pollutants with pterygium or pterygium recurrence after surgery were examined using multivariate logistic models, after adjusting for several covariates. Distributed lag models were additionally used for estimating cumulative effects of air pollution on pterygium. None of air pollution factors was significantly associated with pterygium or pterygium recurrence (each P > 0.05). Distributed lag models also showed that air pollution factors were not associated with pterygium or pterygium recurrence in 0-to-2 year lags (each P > 0.05). However, primary pterygium showed a weak association with PM10 after adjusting for covariates (odds ratio [OR] 1.23; [per 5 μg/m³ PM₁₀ increase]; P = 0.023). Aging, male sex, and greater sun exposure were associated with pterygium, while higher education level and myopia were negatively associated with pterygium (each P ≤ 0.001). Male sex and myopia were negatively associated with pterygium recurrence (each P < 0.05). In conclusion, exposure to higher PM10 levels was associated with primary pterygium, although this study observed no significant association between air pollution and overall pterygium or pterygium recurrence in Korean adults.

Prevalence and Risk Factors for Self-Reported Visual Impairment Among Middle-Aged and Older Adults

This study examined the prevalence of and risk factors for self-reported visual impairment among American adults. Data were collected via telephone interviews with a nationally representative sample ( n= 1,219) aged 45 and older and were weighted for population parameter estimates. Hierarchical logistic regression examined independent risk factors of self-reported visual impairment. Seventeen percent of adults aged 45 and older self-reported visual impairments, increasing to 26.5% of those aged 75 and older. Greater age, not being Hispanic, in poor or fair self-rated health, and low availability of informal social support were significant risk factors associated with visual impairment. The prevalence of vision problems among adults suggests unmet needs for both basic eye care and vision rehabilitation interventions to reduce functional limitations that can result from visual impairment. Longitudinal research is needed to examine prevalence and incidence of vision loss as a function of population aging and changing health behaviors.

Poverty and Blindness in Nigeria: Results from the National Survey of Blindness and Visual Impairment

PURPOSE

Poverty can be a cause and consequence of blindness. Some causes only affect the poorest communities (e.g. trachoma), and poor individuals are less likely to access services. In low income countries, cataract blind adults have been shown to be less economically active, indicating that blindness can exacerbate poverty. This study aims to explore associations between poverty and blindness using national survey data from Nigeria.

METHODS

Participants ≥40 years were examined in 305 clusters (2005-2007). Sociodemographic information, including literacy and occupation, was obtained by interview. Presenting visual acuity (PVA) was assessed using a reduced tumbling E LogMAR chart. Full ocular examination was undertaken by experienced ophthalmologists on all with PVA <6/12 in either eye. Causes of vision loss were determined using World Health Organization guidelines. Households were categorized into three levels of poverty based on literacy and occupation at household level.

RESULTS

A total of 569/13,591 participants were blind (PVA <3/60, better eye; prevalence 4.2%, 95% confidence interval [CI] 3.8-4.6%). Prevalences of blindness were 8.5% (95% CI 7.7-9.5%), 2.5% (95% CI 2.0-3.1%), and 1.5% (95% CI 1.2-2.0%) in poorest, medium and affluent households, respectively (p = 0.001). Cause-specific prevalences of blindness from cataract, glaucoma, uncorrected aphakia and corneal opacities were significantly higher in poorer households. Cataract surgical coverage was low (37.2%), being lowest in females in poor households (25.3%). Spectacle coverage was 3 times lower in poor than affluent households (2.4% vs. 7.5%).

CONCLUSION

In Nigeria, blindness is associated with poverty, in part reflecting lower access to services. Reducing avoidable causes will not be achieved unless access to services improves, particularly for the poor and women.

Relationship of socioeconomic factors with vision-related quality of life on severe low vision and blind population in Indonesia

Background: Socioeconomic factors are known to be associated with visual impairment. Being someone who is visually impaired could affect his quality of life. The aim of this study is to evaluate the quality of life (QOL) in severe low vision and blind population in Indonesia in relation to their socioeconomic status. Methods: A cross sectional population-based study was performed in 5 provinces, in Indonesia. Respondents of validation study on blindness data of national basic health survey 2013 (RISKESDAS 2013), who were above 18 years old with severe low vision (BCVA≥3/60 to 6/60) and blind (BCVA<3/60), were included in this study. Questionnaires for socioeconomic status and a questionnaire from the national eye institute visual function questionnaire 25 (NEI VFQ 25) for visual function were administered. Total  scores of NEI-VFQ25 were compared based on severity of visual impairment, educational level, occupation, literacy adequacy, income level, and residency. Data analysis was using independent T-test or Mann-Whitney test, and Chi square test.Results: A total of 134 subjects were enrolled in this study, most of them are  women (68.2%), aged >64 years old (64.9%) with low education (65.7%), illiterate (52.2%), low income (71.6%), non working (63.4%) and living in urban areas (58.2%). The blind population has lower VFQ scores than severe low vision (p=0.001). Different status of educational level, literacy adequacy, income level and residency did not show significant difference in VFQ scores, but those who have an occupation had better VFQ scores than those who do not (p=0.041).Conclusion: Visual related quality of life (VRQOL) of severe low vision and blind population was associated significantly with occupational status. Because of culture and characteristics of Indonesian people, VRQOL of severe low vision and blind population in Indonesia was not affected by educational level, literacy, income level, and residency.

Epidemiology and Associated Morbidity of Pterygium: A Large, Community-Based Case-Control Study

BACKGROUND

To evaluate the prevalence and risk factors of various conditions among patients with pterygium.

METHODS

A retrospective observational case control study of 4,037 patients who were diagnosed with pterygium in the Central District of Clalit Health Services in Israel from 2000-2009. A total of 16,054 randomly selected controls from the district HMO members. Personal, medical, and demographic information were extracted from patients' files. We calculated the prevalence of various ocular, systemic, and demographic conditions as risk factors for pterygium.

RESULTS

The average age of pterygium patients was 58.4 ± 14 years; 56.9% were male. A significant tendency to develop pterygium was found among individuals of lower socioeconomic status (p < 0.001) and in populations living in rural areas (p < 0.001). A logistic regression model adjusted to marital status, socio-economic class, and area of living was performed. The following conditions were significantly associated with pterygium: blepharitis (OR = 1.71; 99.9% CI: 1.53-1.93), chalazia (OR = 1.46; 99.9% CI: (1.19-1.78)), anxiety (OR = 1.14, 99.9% CI: 0.98-1.33), and G6PD deficiency (OR = 1.85; 99.9% CI: 1.11-3.07). Schizophrenia (OR 0.31; 99.9% CI: 0.19-0.50) and smoking (OR 0.82; 99.9% CI: 0.76-0.89) were significantly less prevalent among pterygium patients.

CONCLUSIONS

Pterygium etiology is multifactorial. Some demographic, systemic, and periocular conditions are significantly more prevalent and some are less prevalent among pterygium patients. Better understanding of the pathophysiological association between those diseases and pterygium may help in its prevention and treatment.

Age-related eye diseases and visual impairment among U.S. adults

BACKGROUND

Visual impairment is a common health-related disability in the U.S. The association between clinical measurements of age-related eye diseases and visual impairment in data from a national survey has not been reported.

PURPOSE

To examine common eye conditions and other correlates associated with visual impairment in the U.S.

METHODS

Data from the 2005-2008 National Health and Nutrition Examination Survey of 5222 Americans aged ≥40 years were analyzed in 2012 for visual impairment (presenting distance visual acuity worse than 20/40 in the better-seeing eye), and visual impairment not due to refractive error (distance visual acuity worse than 20/40 after refraction). Diabetic retinopathy (DR) and age-related macular degeneration (AMD) were assessed from retinal fundus images; glaucoma was assessed from two successive frequency-doubling tests and a cup-to-disc ratio measurement.

RESULTS

Prevalence of visual impairment and of visual impairment not due to refractive error was 7.5% (95% CI=6.9%, 8.1%) and 2.0% (1.7%, 2.3%), respectively. The prevalence of visual impairment not due to refractive error was significantly higher among people with AMD (2.2%) compared to those without AMD (0.8%), or with DR (3.5%) compared to those without DR (1.2%). Independent predictive factors of visual impairment not due to refractive error were AMD (OR=4.52, 95% CI=2.50, 8.17); increasing age (OR=1.09 per year, 95% CI=1.06, 1.13); and less than a high school education (OR=2.99, 95% CI=1.18, 7.55).

CONCLUSIONS

Visual impairment is a public health problem in the U.S. Visual impairment in two thirds of adults could be eliminated with refractive correction. Screening of the older population may identify adults at increased risk of visual impairment due to eye diseases.

Relationship of sociodemographic variables with outcomes after cataract surgery

PURPOSE

The objective of this study is to analyse the relationship between sociodemographic characteristics of patients undergoing cataract extraction and their outcomes.

METHODS

The method comprised a prospective cohort study of patients recruited from 17 hospitals of different areas of Spain. Data gathered before surgery included sociodemographic variables, visual acuity, and visual function (using the Visual Function Index-14). After surgery, we assessed visual acuity and visual function at 6 weeks and at 3 months, respectively. Multivariate multilevel analysis was performed to assess the relationship of sociodemographic variables with changes in visual acuity and function, analysing whether improvements surpassed the minimal clinically important differences (MCIDs).

RESULTS

Multivariate analysis showed that for visual acuity, (i) older men had a lower odds ratio (OR) of surpassing the MCID (OR: 65-75 years, 0.64; >75 years, 0.51); (ii) those with primary (1.65) or secondary (1.41) education had higher ORs than those with no formal education; and (iii) those living in a residential home had a lower OR than men living alone (0.36). In women, we found that the higher the educational level, the greater the improvement in visual acuity (primary, 1.41; secondary, 1.76), whereas socially dependent women (0.70) were less likely to exceed the MCID. With regards to predictors related to achievement of an MCID in visual function, only dependency was associated with more improvement in men (OR: 1.39), whereas in women the educational level was the only predictor (primary: 0.72; secondary: 0.61).

CONCLUSIONS

This study found that patients with certain sociodemographic characteristics were less likely to experience an MCID in visual acuity or visual function after cataract surgery.

Social inequalities in blindness and visual impairment: a review of social determinants

Health inequities are related to social determinants based on gender, socioeconomic status, ethnicity, race, living in a specific geographic region, or having a specific health condition. Such inequities were reviewed for blindness and visual impairment by searching for studies on the subject in PubMed from 2000 to 2011 in the English and Spanish languages. The goal of this article is to provide a current review in understanding how inequities based specifically on the aforementioned social determinants on health influence the prevalence of visual impairment and blindness. With regards to gender inequality, women have a higher prevalence of visual impairment and blindness, which cannot be only reasoned based on age or access to service. Socioeconomic status measured as higher income, higher educational status, or non-manual occupational social class was inversely associated with prevalence of blindness or visual impairment. Ethnicity and race were associated with visual impairment and blindness, although there is general confusion over this socioeconomic position determinant. Geographic inequalities and visual impairment were related to income (of the region, nation or continent), living in a rural area, and an association with socioeconomic and political context was suggested. While inequalities related to blindness and visual impairment have rarely been specifically addressed in research, there is still evidence of the association of social determinants and prevalence of blindness and visual impairment. Additional research should be done on the associations with intermediary determinants and socioeconomic and political context.

Visual acuity and associated factors. The Central India Eye and Medical Study

Visual acuity is a major parameter for quality of vision and quality of life. Information on visual acuity and its associated factors in rural societies almost untouched by any industrialization is mostly non-available. It was, therefore, the purpose of our study to determine the distribution of visual acuity and its associated factors in a rural population not marked influenced by modern lifestyle. The population-based Central India Eye and Medical Study included 4711 subjects (aged 30+ years), who underwent a detailed ophthalmologic examination including visual acuity measurement. Visual acuity measurements were available for 4706 subjects with a mean age of 49.5±13.4 years (range: 30–100 years). BCVA decreased significantly (P<0.001) from the moderately hyperopic group (0.08±0.15 logMAR) to the emmetropic group (0.16±0.52 logMAR), the moderately myopic group (0.28±0.33 logMAR), the highly hyperopic group (0.66±0.62 logMAR) and finally the highly myopic group (1.32±0.92 logMAR). In multivariate analysis, BCVA was significantly associated with the systemic parameters of lower age (P<0.001), higher level of education (P<0.001), higher body stature (P<0.001) and higher body mass index (P<0.001), and with the ophthalmic parameters of more hyperopic refractive error (spherical equivalent) (P<0.001), shorter axial length (P<0.001), lower degree of nuclear cataract (P<0.001), and lower intraocular pressure (P = 0.006). The results suggest that in the rural population of Central India, major determinants of visual acuity were socioeconomic background, body stature and body mass index, age, refractive error, cataract and intraocular pressure.

Risk factors for four-year incident visual impairment and blindness: the Los Angeles Latino Eye Study

PURPOSE

To identify independent risk factors for incident visual impairment (VI) and monocular blindness.

DESIGN

Population-based prospective cohort study.

PARTICIPANTS

A total of 4658 Latinos aged 40 years in the Los Angeles Latino Eye Study (LALES).

METHODS

A detailed history and comprehensive ophthalmologic examination was performed at baseline and at the 4-year follow-up on 4658 Latinos aged ≥40 years from Los Angeles, California. Incident VI was defined as best-corrected visual acuity (BCVA) of <20/40 and >20/200 in the better-seeing eye at the 4-year follow-up examination in persons who had a BCVA of ≥20/40 in the better-seeing eye at baseline. Incident monocular blindness was defined as BCVA of ≤20/200 in 1 eye at follow-up in persons who had a BCVA >20/200 in both eyes at baseline. Sociodemographic and clinical risk factors identified at the baseline interview and examination and associated with incident VI and loss of vision were determined using multivariable regression. Odds ratios (ORs) were calculated for those variables that were independently associated with VI and monocular blindness.

MAIN OUTCOME MEASURES

Odds ratios for various risk factors for incident VI and monocular blindness.

RESULTS

Independent risk factors for incident VI were older age (70-79 years, OR 4.8; ≥80 years OR 17.9), unemployment (OR 3.5), and diabetes mellitus (OR 2.2). Independent risk factors for monocular blindness were being retired (OR 3.4) or widowed (OR 3.7) and having diabetes mellitus (OR 2.1) or any ocular disease (OR 5.6) at baseline. Persons with self-reported excellent/good vision were less likely to develop VI or monocular blindness (OR 0.4-0.5).

CONCLUSIONS

Our data highlight that older Latinos and Latinos with diabetes mellitus or self-reported eye diseases are at high risk of developing vision loss. Furthermore, being unemployed, widowed, or retired confers an independent risk of monocular blindness. Interventions that prevent, treat, and focus on the modifiable factors may reduce the burden of vision loss in this fastest growing segment of the US population.

Level of education associated with ophthalmic diseases. The Beijing Eye Study

OBJECTIVE

To determine associations between educational level and ophthalmic diseases in Chinese.

METHODS

The population-based Beijing Eye Study, performed in 2006, enrolled 3,251 participants (age: 45+ years) out of 4,439 subjects invited to participate (response rate: 73.2%). The participants underwent an interview including questions concerning their educational level, and a detailed ophthalmic examination.

RESULTS

Data on the level of education were available for 3,221 (99.1%) subjects, with 1,484 (46.1%) subjects living in the rural region. The mean age was 60.4 +/- 10.1 years (range: 45-89 years). In a multivariate analysis, a higher level of education was significantly associated with myopic refractive error, higher best-corrected visual acuity, lower degree of nuclear cataract, and lower prevalence of angle-closure glaucoma, and with the systemic parameters of lower age, male gender, urban region, taller body height, and lower body mass index. It was not significantly associated with intraocular pressure, amount of subcapsular cataract and cortical cataract, cataract surgery, and the prevalences of diabetes mellitus, retinal vein occlusions, chronic open-angle glaucoma, and age-related macular degeneration, and with the systemic parameters of fasting serum concentrations of glucose, high-density lipoproteins, low-density lipoproteins, cholesterol and triglycerides, systolic and diastolic blood pressure.

CONCLUSIONS

In the Greater Beijing area, a higher level of education was associated with myopic refractive error, higher best-corrected visual acuity, and lower prevalence of nuclear cataract and angle-closure glaucoma, after adjusting for the systemic parameters of younger age, male gender, urban region, taller body height, lower body mass index less smoking and less alcohol consumption. Educational level was not significantly associated with intraocular pressure, cortical cataract, blood pressure, and frequencies of age-related macular degeneration, retinal vein occlusions and chronic open-angle glaucoma.

Vision and Hearing Impairment in Aged Care Clients

PURPOSE

To determine the frequency of sensory impairments among aged care clients.

METHODS

We examined 188 persons aged 65-99 years being evaluated for aged care services at a geriatric assessment center, west of Sydney, Australia. Visual acuity was measured using a LogMAR chart. Visual impairment was defined in the better eye: mild < 20/40 to > or = 20/80, moderate < 20/80 to > or = 20/200, and severe < 20/200. Hearing function was assessed by portable pure-tone air-conduction audiometry. Hearing loss was defined using average hearing thresholds in the better ear: mild > 25 to < or = 40 decibels (dB), moderate > 40 to < or = 60dB, and severe > 60dB.

RESULTS

Vision, hearing, or both were randomly tested in 96, 93, and 49 aged care clients, respectively. Vision impairment was found in 30.2% of clients. Distance vision could be improved with pinhole in 16.7% of 84 clients with presenting VA < 20/20. Moderate to severe hearing loss was present in 50.5%. Combined sensory impairment was detected in 22.5% of persons having both tests. The age-standardized proportions with vision impairment was 25.6%, higher than the rate (17.4%) found in the Blue Mountains Eye Study (BMES) community population, but lower than the 37.7% prevalence reported from the BMES nursing home sample. Hearing impairment was also more common in aged care clients (28.1% vs 17.5%).

CONCLUSIONS

This study suggests a high prevalence of sensory impairment among older persons transitioning from independent community living to institutionalized care.

Visual acuity in northern China in an urban and rural population: the Beijing Eye Study

AIM

To evaluate prevalence and demographic associations of visual impairment in an urban and rural population in northern China.

METHODS

In the Beijing Eye Study, a population based cohort study in northern China, visual acuity was assessed for 8876 eyes (4438 subjects) according to a response rate of 83.4%. The study was divided into a rural part (1972 subjects) and an urban part (n=2466). Mean age was 56.20 (SD 10.59) years (median 56 years; range 40-101 years).

RESULTS

Mean uncorrected visual acuity measured 0.72 (0.32) (median, 0.80), and mean best corrected visual acuity measured 0.91 (0.21) (median, 1.0). In a multiple regression analysis, best corrected visual acuity was significantly correlated with age (p<0.001), degree of nuclear cataract (p<0.001), amount of cortical cataract (p=0.014), amount of subcapsular cataract (p<0.001), educational background (p<0.001), and refractive error (p<0.001). Rural region versus urban region (p=0.34) and sex (p=0.053) were not statistically significantly associated with best corrected visual acuity.

CONCLUSIONS

In northern China, determinants of a low degree of best corrected visual acuity are age, cataract, low educational background, and myopia. Despite marked differences in educational background and family income, sex, and rural area versus urban area are not markedly associated with best corrected visual acuity.

The prevalence and causes of visual impairment in Tehran: the Tehran Eye Study

AIMS

To determine the prevalence and causes of visual impairment in Tehran, Iran, through a population based study.

METHODS

In a population based, cross sectional study, 6497 Tehran citizens were sampled from 160 clusters using a stratified, random, cluster sampling strategy. The eligible people were enumerated through a door to door household survey in the selected clusters and were invited. All participants were transferred to a clinic for an extensive eye examination and interview. Visual impairment was determined using presenting and best corrected visual acuity (low vision: visual acuity of less than 6/18 to 3/60 in the better eye; blindness: visual acuity of less than 3/60 in the better eye).

RESULTS

Of those sampled, 4565 (70.3%) people participated in the study. The age and sex standardised prevalences of visual impairment on the basis of best corrected and presenting visual acuity were 1.39% (95% confidence interval (CI), 1.07 to 1.71) and 2.52% (95% CI, 2.07 to 2.97), respectively. 15 people (0.28%; 95% CI, 0.14 to 0.42) were blind with corrected vision while 22 (0.39%; 95% CI, 0.23 to 0.56) were blind with presenting vision. Using the corrected and presenting vision, the prevalence of low visual impairment was 1.11% (95% CI, 0.84 to 1.39) and 2.13% (95% CI, 1.71 to 2.55), respectively. The causes of visual impairment according to the best corrected vision were cataract (36.0%), macular degeneration (20.0%), and amblyopia (10.7%). However, according to the presenting vision, uncorrected refractive errors were the most frequent primary cause (33.6%) and cataract (25.4%), macular degeneration (12.7%), and amblyopia (8.2%) were the other main causes of visual impairment in the study sample. The prevalence of visual impairment was associated with advancing age and lower education.

CONCLUSION

The results indicate that the burden of visual impairment is important and, although easily preventable, uncorrected refractive errors and cataract have a major role as causes of visual impairment in this population. Results also highlight the need for visual impairment prevention programmes, with emphasis on treatment of refractive errors and cataract.

The Oslo Health Study: The impact of self-selection in a large, population-based survey

Background

Research on health equity which mainly utilises population-based surveys, may be hampered by serious selection bias due to a considerable number of invitees declining to participate. Sufficient information from all the non-responders is rarely available to quantify this bias. Predictors of attendance, magnitude and direction of non-response bias in prevalence estimates and association measures, are investigated based on information from all 40 888 invitees to the Oslo Health Study.

Methods

The analyses were based on linkage between public registers in Statistics Norway and the Oslo Health Study, a population-based survey conducted in 2000/2001 inviting all citizens aged 30, 40, 45, 59–60 and 75–76 years. Attendance was 46%. Weighted analyses, logistic regression and sensitivity analyses are performed to evaluate possible selection bias.

Results

The response rate was positively associated with age, educational attendance, total income, female gender, married, born in a Western county, living in the outer city residential regions and not receiving disability benefit. However, self-rated health, smoking, BMI and mental health (HCSL) in the attendees differed only slightly from estimated prevalence values in the target population when weighted by the inverse of the probability of attendance.

Observed values differed only moderately provided that the non-attending individuals differed from those attending by no more than 50%. Even though persons receiving disability benefit had lower attendance, the associations between disability and education, residential region and marital status were found to be unbiased. The association between country of birth and disability benefit was somewhat more evident among attendees.

Conclusions

Self-selection according to sociodemographic variables had little impact on prevalence estimates. As indicated by disability benefit, unhealthy persons attended to a lesser degree than healthy individuals, but social inequality in health by different sociodemographic variables seemed unbiased. If anything we would expect an overestimation of the odds ratio of chronic disease among persons born in non-western countries.

Visual impairment in a Taiwanese population: prevalence, causes, and socioeconomic factors

PURPOSE

We sought to estimate the prevalence of visual impairment among an elderly population in urban Taiwan, determine the causes of visual impairment, and gain information about certain socioeconomic factors associated with visual impairment.

METHODS

A population-based survey of ocular diseases in residents aged 50 years or older was conducted in Peitou Precinct, Taipei, Taiwan. All participants underwent a comprehensive ophthalmic examination, including visual acuity measurement, using standardized protocols. Demographic data, marital status, employment status, and educational level were gathered through an interview.

RESULTS

A total of 2034 participants completed the visual acuity measurements. The prevalence of visual impairment (defined as best-corrected visual acuity in the better eye <6/18) among this population was 2.75% (95% confidence intervals: 2.04%-3.46%). Three major causes of visual impairment were cataract (30.4%), high myopic macular degeneration (25.0%), and age-related macular degeneration (14.3%). In multivariate analysis, age was positively correlated with visual impairment (P < 0.001), and higher education level was associated with a significant decrease in the odds of being visually impaired (P < 0.001). No relation was found between visual impairment and sex, or marital and employment status. CONCLUSIONS This study provides the first information about the prevalence and causes of visual impairment in Taiwan, and identifies age and educational level as the most important factors related to visual impairment. Additional educational programs should be developed to improve individual awareness of age-related ocular diseases and the availability of current ophthalmic intervention.

Assessing disability in the patient with cataracts

Snellen chart visual acuity has been the gold standard to measure the preoperative indication of cataract surgery as well as the postoperative outcome. To a patient with cataracts, the disability goes beyond their loss of visual acuity. Glare disability has often been studied independently. Newer studies, however, show that there is more integration with clinical and nonclinical vision. For example, studies are looking at integrating unilateral versus bilateral procedures, type of cataract, type of procedure, the patient's daily needs, and the patient's state of mental and physical health. Questionnaires are being developed to bring into focus nonclinical issues of visual function and quality of life. Understanding the full spectrum of disability associated with visual impairment from cataracts can help clinicians improve their approach to treatment and rehabilitation of these patients.