Undercorrected Refractive Error Research Articles

Six-Year Incidence of Visual Impairment in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Diseases Study

To examine the 6-year incidence of visual impairment (VI) and identify risk factors associated with VI in a multiethnic Asian population. Prospective, population-based, cohort study. Adults aged ≥ 40 years were recruited from the Singapore Epidemiology of Eye Diseases cohort study at baseline. Eligible subjects were re-examined after 6 years. Subjects included in the final analysis had a mean age of 56.1±8.9 years, and 2801 (50.5%) were female. All participants underwent standardized examination and interviewer-administered questionnaire at baseline. Incidences were standardized to the Singapore Population Census 2010. A Poisson binomial regression model was used to evaluate the associations between baseline factors and incident presenting VI. Incident presenting VI was assessed at the 6-year follow-up visit. Visual impairment (presenting visual acuity < 20/40), low vision (presenting visual acuity < 20/40 but ≥ 20/200), and blindness (presenting visual acuity < 20/200) were defined based on United States definition. A total of 5551 subjects (2188 Chinese, 1837 Indians, and 1526 Malays) were evaluated, of whom 514 developed incident presenting VI over 6 years. Malays had a higher incidence of low vision and blindness (13.0%; 0.6%) than Indians (7.0%; 0.1%) and Chinese (7.7%; 0.2%). Among Malay individuals with VI at baseline, 52.8% remained visually impaired after 6 years, which was considerably higher than Chinese (32.4%) and Indians (37.2%). Older age (per decade; relative risk [RR]=1.59), a history of cardiovascular disease (RR=1.38), current smoking (RR=1.31), smaller housing type (1- to 2-room public flat; RR=2.01), and no formal education (RR=1.63) at baseline were associated with a higher risk of incident VI (all P≤0.027). Older age (> 60 years) contributed the highest population attributable risk to incident VI (27.1%), followed by lower monthly income (Singapore dollar < $2000; 26.4%) and smaller housing type (24.7%). Overall, undercorrected refractive error (49.1%) and cataract (82.6%) were leading causes for low vision and blindness, respectively. This was consistently observed across the 3 ethnicities. In this multiethnic Asian population, Malays had a higher VI incidence compared to Indians and Chinese. Leading causes of VI are mostly treatable, suggesting that more efforts are needed to further mitigate preventable visual loss. The authors have no proprietary or commercial interest in any materials discussed in this article.

The Association of Vision Concerns With the Physical and Mental Well-being of Adolescents in the United States

To describe the prevalence of vision concerns among US adolescents and the association of time spent worrying about eyesight with physical and mental health. Cross-sectional study. This study included adolescent children (age 12 to ≤18 years) particpating in the 2005-2008 National Health and Nutrition Examination Survey with completed visual function questionnaires and eye examinations. Vision concerns were identified by a survey question of time spent worrying about eyesight and response was treated as a dichotomous variable. Recent poor physical and mental health was defined as at least 1 day of poor health within the last month. Odds ratios (ORs) derived from survey-weighted multivariable logistic regression models were used to identify factors associated with vision concerns in the adolescent population, adjusting for participant demographics and refractive correction. The survey participants included 3100 adolescents (mean [SD] age, 15.5 [2.0] years; 49% [n=1545] female). Vision concerns were expressed by 24% (n=865) of adolescents. Vision concerns were more prevalent among female (29% vs 19%, P < .001), low-income (30% vs 23%, P < .001), and uninsured (31% vs 22%, P=.006) adolescents. Participants worried about their eyesight were more likely to have undercorrected refractive error (OR 2.07, 95% CI 1.43-2.98). Poor recent mental health (OR 1.30, 95% CI 1.01-1.67), but not physical health (OR 1.00, 95% CI 0.69-1.45), was associated with adolescent vision concerns. Female, low-income, and uninsured adolescents living in the United States are more likely to report worrying about their vision and often have uncorrected or undercorrected refractive errors.

The longitudinal association between cognitive impairment and incident visual impairment in a multiethnic Asian population: a prospective cohort study.

The relationship between baseline cognitive impairment (CI) and incident visual impairment (VI) in Asians is unclear. To determine the associations between baseline CI with incident VI and visual acuity (VA) at 6-year follow-up in multiethnic Asians. Cohort. Population-based. Two thousand three hundred and twenty-four adults aged ≥60years from the Singapore Epidemiology of Eye Diseases Study (response rate 64%). CI was defined using the validated Abbreviated Mental Test (AMT). VA was objectively measured using a LogMAR chart. Any incident VI was defined as having no VI (Snellen's VA better than or equal to 20/40) at baseline but present (VA worse than 20/40) at 6-year follow-up. VI severity was defined according to the International Classification of Diseases, 11th Revision. Associations were assessed using logistic and linear regression models. Of the 2,324 participants, 248 had CI at baseline. Presence of baseline CI was associated with more than twice the odds of any incident VI, incident mild and moderate-severe VI (OR [95% confidence interval]: 2.48 [1.55-3.90], 2.07 [1.17-3.55], and 2.61 [1.36-4.93], respectively) and worse VA (β [95% confidence interval]: 0.026 [0.006-0.046]) at 6-year follow-up. The leading causes of incident VI were cataract and under-corrected refractive error. Older adults with CI had more than double the odds of VI development and poorer VA than their cognitively intact counterparts, and most causes of incident VI were correctable. Strategies such as targeted vision screening and early intervention for early detection and management of vision loss in patients with cognitive decline are warranted.

Impact of visual impairment on balance and visual processing functions in students with special educational needs.

IntroductionVision is critical for children’s development. However, prevalence of visual impairment (VI) is high in students with special educational needs (SEN). Other than VI, SEN students are prone to having functional deficits. Whether visual problems relate to these functional deficits is unclear. This study aimed to assess the impact of vision on visual processing functions and balance in SEN students through a community service.MethodsVisual acuity (VA) and contrast sensitivity were measured in a total of 104 (aged 14.3±4.3) SEN students as the visual outcomes, followed by retinoscopy. Visual processing function assessment included facial expression recognition by card matching examiner’s facial expression matching, and visual orientation recognition. Dynamic balance, by Timed Up and Go test, and static standing balance (postural sway in double-legged standing with feet-together and tandem-stance for open-eye and closed-eye conditions) were assessed. Static balance was presented in terms of the maximal medial-lateral and antero-posterior sways.ResultsOf the 104 students, 62 (59.6%) were classified as visually impaired according to WHO classification of visual impairment based on presenting distance acuity. Ocular problems (e.g. optic nerve anomaly, uncorrected/ under-corrected refractive errors) and neurological anomalies were the major causes of vision loss. VA was positively associated with visual processing functions (all p ≤ 0.01), as SEN students with better vision tended to perform better in visual orientation and facial expression recognition tasks, as well as dynamic balance function (p = 0.04). For the static balance, postural sway and VA showed a positive relationship under open-eye and tandem stance conditions. However, the relationship between postural sway and VA became negative under closed-eye and tandem stance conditions.ConclusionThis study found a high prevalence of SEN students with visual impairment, in which many of them were undetected. Optometric examination is important to improve their visual function to minimize the effect of vision on functional performance. Vision is critical in visual processing as well as playing an important role in maintaining balance in SEN students.

Study on stereoacuity and associated factors in school children aged 7 to 14 years.

Purpose:The study aimed to estimate the prevalence of subnormal stereoacuity in school children and to assess the factors associated with it.Methods:In this prospective cross-sectional study, a total of 2,376 school children without amblyopia and manifest squint were screened by the titmus fly test, Snellen chart, tests for heterophoria, anterior segment examination, and fundoscopy. Children with a manifest squint, amblyopia (best-corrected visual acuity [BCVA] <6/18), and history of ocular trauma or surgery, and one-eyed children were excluded. Cycloplegic refraction was done in children with uncorrected or undercorrected refractive errors, and stereoacuity was assessed again with spectacle correction.Results:The prevalence of normal stereoacuity by titmus fly test was 93.18% with correction of refractive errors. Girls had slightly better stereopsis compared with boys. The subnormal stereoacuity was significantly associated with refractive error (P < 0.00001, significant at P < 0.05), unilateral refractive error (P < 0.00001, significant at P < 0.05), bilateral refractive error (P < 0.00001, significant at P < 0.05), anisometropia (P < 0.00001, significant at P < 0.05), ametropia (P < 0.00001, significant at P < 0.05), lower BCVA (P < 0.00001, significant at P < 0.05), hyperopia (P < 0.05, significant at P < 0.05), and heterophoria (P = 0.014, significant at P < 0.05). The subnormal stereoacuity was positively correlated with the magnitude of refractive error of the eyes.Conclusion:This study underlines the significant impact of identification and correction of refractive errors and squints in school children. The measurement of stereoacuity will be of immense importance and must be included in the screening programs for children.

Visual Impairment, Major Eye Diseases, and Mortality in a Multi-Ethnic Asian Population and a Meta-analysis of Prospective Studies

Vision impairment (VI) is associated with poor quality of life and increased risk of falls. Few prospective data are available on Asians. This study investigates the longitudinal impact of VI and the major eye diseases on mortality risk in Asians. Prospective cohort study with meta-analysis. We conducted a multi-ethnic prospective study of adults (40-80 years old) in the Singapore Epidemiology of Eye Diseases Study (baseline: 2004-2011). All-cause mortality was obtained from the National Death Registry until May 2017. VI was defined by best-corrected visual acuity (BCVA) <20/40 in the better eye. Major eye diseases were assessed using standard protocols. We examined associations using multivariate-adjusted Cox proportional hazards regression models. Finally, we conducted a meta-analysis of the associations between VI and mortality. Of 9,986 participants, 1,210 deaths occurred (12.1%) over a median follow-up of 8.8 years. Compared to participants with normal vision, persons with VI had increased risk of mortality (hazards ratio [HR]: 1.53; 95% confidence interval [CI:] 1.30-1.81) in multivariate models. In ethnicity-specific analyses, this association was significant across Chinese (HR: 1.63; 95% CI: 1.08-2.48); Malays (HR: 1.31; 95% CI: 1.06-1.62); and Indians (HR: 2.25; 95% CI: 1.61-3.15). Cataract, under-corrected refractive errors (URE), and diabetic retinopathy (DR) were significantly associated with mortality (HRs: 1.30, 1.22, and 1.54, respectively). In a meta-analysis of 12 studies including 58,034 persons, VI was associated with 30% increased risk of mortality (HR: 1.3; 95% CI: 1.2-1.5). In this multi-ethnic Asian population, VI and preventable eye conditions (cataract, URE, and DR) were associated with mortality, emphasizing the need for early detection and intervention to prevent and treat VI and major eye diseases.

Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study

Background Many causes of vision impairment can be prevented or treated. With an ageing global population, the demands for eye health services are increasing. We estimated the prevalence and relative contribution of avoidable causes of blindness and vision impairment globally from 1990 to 2020. We aimed to compare the results with the World Health Assembly Global Action Plan (WHA GAP) target of a 25% global reduction from 2010 to 2019 in avoidable vision impairment, defined as cataract and undercorrected refractive error. Methods We did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980, to October, 2018. We fitted hierarchical models to estimate prevalence (with 95% uncertainty intervals [UIs]) of moderate and severe vision impairment (MSVI; presenting visual acuity from <6/18 to 3/60) and blindness (<3/60 or less than 10° visual field around central fixation) by cause, age, region, and year. Because of data sparsity at younger ages, our analysis focused on adults aged 50 years and older. Findings Global crude prevalence of avoidable vision impairment and blindness in adults aged 50 years and older did not change between 2010 and 2019 (percentage change –0·2% [95% UI –1·5 to 1·0]; 2019 prevalence 9·58 cases per 1000 people [95% IU 8·51 to 10·8], 2010 prevalence 96·0 cases per 1000 people [86·0 to 107·0]). Age-standardised prevalence of avoidable blindness decreased by –15·4% [–16·8 to –14·3], while avoidable MSVI showed no change (0·5% [–0·8 to 1·6]). However, the number of cases increased for both avoidable blindness (10·8% [8·9 to 12·4]) and MSVI (31·5% [30·0 to 33·1]). The leading global causes of blindness in those aged 50 years and older in 2020 were cataract (15·2 million cases [9% IU 12·7–18·0]), followed by glaucoma (3·6 million cases [2·8–4·4]), undercorrected refractive error (2·3 million cases [1·8–2·8]), age-related macular degeneration (1·8 million cases [1·3–2·4]), and diabetic retinopathy (0·86 million cases [0·59–1·23]). Leading causes of MSVI wer

Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study

SummaryBackgroundMany causes of vision impairment can be prevented or treated. With an ageing global population, the demands for eye health services are increasing. We estimated the prevalence and relative contribution of avoidable causes of blindness and vision impairment globally from 1990 to 2020. We aimed to compare the results with the World Health Assembly Global Action Plan (WHA GAP) target of a 25% global reduction from 2010 to 2019 in avoidable vision impairment, defined as cataract and undercorrected refractive error.MethodsWe did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980, to October, 2018. We fitted hierarchical models to estimate prevalence (with 95% uncertainty intervals [UIs]) of moderate and severe vision impairment (MSVI; presenting visual acuity from <6/18 to 3/60) and blindness (<3/60 or less than 10° visual field around central fixation) by cause, age, region, and year. Because of data sparsity at younger ages, our analysis focused on adults aged 50 years and older.FindingsGlobal crude prevalence of avoidable vision impairment and blindness in adults aged 50 years and older did not change between 2010 and 2019 (percentage change −0·2% [95% UI −1·5 to 1·0]; 2019 prevalence 9·58 cases per 1000 people [95% IU 8·51 to 10·8], 2010 prevalence 96·0 cases per 1000 people [86·0 to 107·0]). Age-standardised prevalence of avoidable blindness decreased by −15·4% [–16·8 to −14·3], while avoidable MSVI showed no change (0·5% [–0·8 to 1·6]). However, the number of cases increased for both avoidable blindness (10·8% [8·9 to 12·4]) and MSVI (31·5% [30·0 to 33·1]). The leading global causes of blindness in those aged 50 years and older in 2020 were cataract (15·2 million cases [9% IU 12·7–18·0]), followed by glaucoma (3·6 million cases [2·8–4·4]), undercorrected refractive error (2·3 million cases [1·8–2·8]), age-related macular degeneration (1·8 million cases [1·3–2·4]), and diabetic retinopathy (0·86 million cases [0·59–1·23]). Leading causes of MSVI were undercorrected refractive error (86·1 million cases [74·2–101·0]) and cataract (78·8 million cases [67·2–91·4]).InterpretationResults suggest eye care services contributed to the observed reduction of age-standardised rates of avoidable blindness but not of MSVI, and that the target in an ageing global population was not reached.FundingBrien Holden Vision Institute, Fondation Théa, The Fred Hollows Foundation, Bill & Melinda Gates Foundation, Lions Clubs International Foundation, Sightsavers International, and University of Heidelberg.

Retrospective review of Duke men’s basketball eye care: annual screenings and traumatic injuries

ABSTRACT Objectives 1) To assess the utility of performing eye screenings for healthy basketball players. 2) To describe the traumatic injuries sustained by competitive college basketball players. Methods The eye screening examinations of the Duke University Men’s Basketball players over six seasons were reviewed retrospectively. Traumatic basketball-related eye injuries amongst Duke University Men’s Basketball players over 16 seasons were also reviewed and described. Results Forty-four total players underwent screening examinations. Thirteen (29.5%) of athletes had uncorrected or under-corrected refractive errors. One athlete was found to have a severe monocular visual deficit secondary to a traumatic injury in childhood, which was significantly mitigated by a contact lens referral. Eight traumatic ocular injuries in eight different athletes, 8.6% of the total roster players in this interval, required ophthalmologic consultation. Most injuries, 7/8, resulted in no permanent visual impairment. However, two severe episodes of injury required operative intervention, and one episode involving a giant retinal dialysis and traumatic optic nerve head avulsion caused severe, permanent visual loss. Most injuries did not result in significant competition time loss, with a median time loss of 5 days (range 0 to 240 days). Conclusion Screening eye examinations in healthy athletes are beneficial for the identification and treatment of refractive errors. Traumatic basketball-related eye injuries are common and result in a wide array of injuries. Although most basketball-related eye injuries do no result in permanent visual loss, given the potential for severe injury, many basketball-related eye injuries require expert ophthalmic consultation.

Prevalence and causes of vision loss in sub-Saharan Africa in 2015: magnitude, temporal trends and projections

BackgroundThis study aimed to assess the prevalence and causes of vision loss in sub-Saharan Africa (SSA) in 2015, compared with prior years, and to estimate expected values for 2020.MethodsA systematic...

Prevalence and causes of blindness and vision impairment: magnitude, temporal trends and projections in South and Central Asia

BackgroundTo assess prevalence and causes of vision loss in Central and South Asia.MethodsA systematic review of medical literature assessed the prevalence of blindness (presenting visual acuity<3/60 in the better eye),...

Prevalence and causes of vision loss in Latin America and the Caribbean in 2015: magnitude, temporal trends and projections

ObjectiveTo estimate the prevalence and causes of blindness and vision impairment for distance and near in Latin America and the Caribbean (LAC) in 2015 and to forecast trends to 2020.MethodsA...

Optical correction of refractive error for preventing and treating eye symptoms in computer users.

Optical correction of refractive error for preventing and treating eye symptoms in computer users.

Accommodative Function in Individuals with Autism Spectrum Disorder.

Accommodative responses were significantly poorer in individuals with autism spectrum disorder (ASD) compared with age-matched typically developing control subjects, and hypoaccommodation was associated with reduced near visual acuity (NVA) and convergence. Autism spectrum disorder is a neurodevelopmental disorder with a reported prevalence of 1.1 to 1.5%. Accommodative dysfunction has been noted in other developmental conditions including cerebral palsy and Down syndrome. The aim of this study was to investigate how accommodative accuracy and near visual function in ASD compared with typically developing control subjects. This study investigated accommodative function in children with ASD, in conjunction with other vision measures with habitual refractive corrections. Accommodative accuracy was assessed using modified Nott dynamic retinoscopy. Individual accommodative demand and response were calculated incorporating residual refractive error (difference between cycloplegic and habitual refractive state). Near visual measures included NVA, near point of convergence, fusional reserves, and stereoacuity. Cycloplegic autorefraction confirmed refractive error. Accommodative responses were measured from 124 participants with ASD (6 to 17 years old) and 204 age-matched control subjects. There was no significant difference in the magnitude of residual refractive error between groups (P = .10). The prevalence of a clinically significant lag of accommodation was greater in the ASD group compared with control subjects (ASD = 17.4%, control subjects = 4.9%, χ = 13.04, P < .0001). Near visual acuity was significantly reduced in the ASD group with a clinically significant lag of accommodation (P < .01). A few participants (n = 24 control subjects, n = 14 ASD) had uncorrected or undercorrected refractive errors (spherical equivalent refractive error ≥+2.00 D, >1.00 DC), and when these were removed from analysis, there was still an increased prevalence of hypoaccommodation in ASD (14.7%). Children with ASD were significantly more likely to have accommodative deficits (and associated near visual deficits) in their presenting refractive state than typically developing children. Appraisal of refractive error, accommodation, and NVA should be considered in visual assessment of children with ASD.

The economic impact of sight loss and blindness in the UK adult population

BackgroundTo quantify the economic impact of sight loss and blindness in the United Kingdom (UK) population, including direct and indirect costs, and its burden on health.MethodsPrevalence data on sight loss and blindness by condition, Census demographic data, data on indirect costs, and healthcare cost databases were used. Blindness was defined as best corrected visual acuity (BCVA) of < 6/60, and sight loss as BCVA < 6/12 to 6/60, in the better-seeing eye.ResultsSight loss and blindness from age-related macular degeneration (AMD), cataract, diabetic retinopathy, glaucoma and under-corrected refractive error are estimated to affect 1.93 (1.58 to 2.31) million people in the UK. Direct health care system costs were £3.0 billion, with inpatient and day care costs comprising £735 million (24.6%) and outpatient costs comprising £771 million (25.8%). Indirect costs amounted to £5.65 (5.12 to 6.22) billion. The value of the loss of healthy life associated with sight loss and blindness was estimated to be £19.5 (15.9 to 23.3) billion or £7.2 (5.9 to 8.6) billion, depending on the set of disability weights used. For comparison with other published results using 2004 disability weights and the 2008 estimates, the total economic cost of sight loss and blindness was estimated to be £28.1 (24.0 to 32.5) billion in 2013. Using 2010 disability weights, the estimated economic cost of sight loss and blindness was estimated to be £15.8 (13.5 to 18.3) billion in 2013.ConclusionsThe large prevalence of sight loss and blindness in the UK population imposes significant costs on public funds, private expenditure, and health. Prevalence estimates relied on dated epidemiological studies and may not capture recent advances in treatment, highlighting the need for population-based studies that track the prevalence of sight-impairing eye conditions and treatment effects over time.

Prevalence and associated risk factors of undercorrected refractive errors among people with diabetes in Shanghai

BackgroundTo investigate the prevalence and risk factors of undercorrected refractive error (URE) among people with diabetes in the Baoshan District of Shanghai, where data for undercorrected refractive error are limited.MethodsThe study was a population-based survey of 649 persons (aged 60 years or older) with diabetes in Baoshan, Shanghai in 2009. One copy of the questionnaire was completed for each subject. Examinations included a standardized refraction and measurement of presenting and best-corrected visual acuity (BCVA), tonometry, slit lamp biomicroscopy, and fundus photography.ResultsThe calculated age-standardized prevalence rate of URE was 16.63% (95% confidence interval [CI] 13.76–19.49). For visual impairment subjects (presenting vision worse than 20/40 in the better eye), the prevalence of URE was up to 61.11%, and 75.93% of subjects could achieve visual acuity improvement by at least one line using appropriate spectacles. Under multiple logistic regression analysis, older age, female gender, non-farmer, increasing degree of myopia, lens opacities status, diabetic retinopathy (DR), body mass index (BMI) index lower than normal, and poor glycaemic control were associated with higher URE levels. Wearing distance eyeglasses was a protective factor for URE.ConclusionThe undercorrected refractive error in diabetic adults was high in Shanghai. Health education and regular refractive assessment are needed for diabetic adults. Persons with diabetes should be more aware that poor vision is often correctable, especially for those with risk factors.

Visual Impairment, Undercorrected Refractive Errors, and Activity Limitations in Older Adults: Findings From the Three-City Alienor Study.

As vision is required in almost all activities of daily living, visual impairment (VI) may be one of the major treatable factors for preventing activity limitations. We aimed to evaluate the attributable risk of VI associated with activity limitations and the extent to which limitations are avoidable with optimal optical correction of undercorrected refractive errors. We analyzed 709 older adults from the Three-City-Alienor population-based study. VI was defined by presenting distance visual acuity in the better-seeing eye. Multivariate modified Poisson regressions were used to estimate the associations between vision, activity limitations, and social participation restrictions. Population attributable risk (PAR) and generalized impact fraction (GIF) were estimated. Bootstrapping was used to estimate 95% confidence intervals (CI). After adjustment for potential confounders, VI was associated with each domain of activity limitations, except basic activities of daily living (ADL) limitations. These associations were found for even minimal levels of VI. PAR was estimated at 10.1% (95% CI: 5.2-10.6) for mobility limitations, at 26.0% (95% CI: 13.5-41.2) for instrumental ADL (IADL) limitations, and at 24.9% (95% CI: 10.5-47.1) for social participation restrictions. GIF for improvement of undercorrected refractive errors was 6.1% (95% CI: 3.8-8.5) for mobility limitations, 15.8% (95% CI: 11.5-20.1) for IADL limitations and 21.4% (95% CI: 13.8-28.5) for social participation restrictions. About one-sixth of IADL limitations and one-fifth of social participation restrictions could be prevented by an optimal optical correction. These results underline the importance of eye examinations in older adults to prevent disability.

Vision impairment and major eye diseases reduce vision-specific emotional well-being in a Chinese population

AimsTo assess the relationship between vision impairment (VI) and major eye diseases, with vision-specific emotional well-being in a Chinese population.MethodsIn this population-based cross-sectional study, 3353 Chinese participants aged 40–80 years...

Prevalence and Risk Factors for Undercorrected Refractive Errors among South Korean: KNHANES 2008-2012

Prevalence and Risk Factors for Undercorrected Refractive Errors among South Korean: KNHANES 2008-2012

Prevalence of undercorrected refractive errors in elderly population aged 60 years and older in Dachang County, Shanghai

Background The undercorrection of refractive error is becoming a major cause of reversible visual impairment worldwide.To investigate and reduce the rate of undercorrected refractive error is one of the primary missions to fight blindness in China. Objective This study was to analyze the prevalence of undercorrected refractive error in residents aged 60 years and older in Dachang County of Baoshan District, Shanghai. Methods This study followed Declaration of Helsinki, and informed consent was obtained from each subject before any medical examination.A cross-sectional study was performed and a random cluster sampling technique was used.All fieldwork was conducted from October to December 2009.All participants were urban population who were changed from the rural population in 10 years ago.The participants received detailed ophthalmic and medical examination, including a standardized refraction and visual acuity examinations, tonometry, slit lamp biomicroscopy, and fundus photography.The undercorrected refractive error was defined based on the criteria of the presenting study, including criterion 1 (the vision improved by ≥1 line after refraction), and criterion 2 (the vision improved by ≥2 lines after refraction). The demographic characteristics of the population with undercorrected refractive error were also analyzed. Results Among the 5 199 people in the project, 4 545 received survey, with the response rate 87.42%.The overall prevalence of undercorrected refractive error was 45.43% or 24.84% based on criterion 1 or criterion 2, respectively.Women and older age were significant risk factors of undercorrected refractive error.The prevalence of undercorrected refractive error was 53.54% for myopia only, 53.06% for hyperopia only, 38.37% for astigmatism only, 38.99% for myopia with astigmatism, and 36.75% for hyperopia with astigmatism.In 401 participants with visual impairment, the prevalence of undercorrected refractive error was 78.80% or 67.58% based on criterion 1 or criterion 2, respectively. Conclusions In rapid urbanization and aging community of Shanghai, undercorrected refractive error is an important cause that affecting the vision of older persons. Key words: Vision; Aged; Epidemiology; Community health services; Refractive error; Undercorrected; Visual impairment; Cross-sectional study