Prevalence and causes of visual impairment according to World Health Organization and United States criteria in an aged, urban Scandinavian population: The Copenhagen City Eye Study

PURPOSE: To evaluate the prevalence and causes of visual impairment in an epidemiologic study of aged, urban individuals in Denmark. DESIGN: Cross-sectional study. PARTICIPANTS: The study population consisted of 1000 randomly selected residents aged 60 to 80 years in Copenhagen, Denmark. Of 976 eligible persons, 946 (96.9%) could be examined. Information about best-corrected visual acuity (VA) was obtained from 944 cooperative persons (96.7%). METHODS: Data from the Copenhagen City Eye Study were used to assess the cause-specific prevalence of visual impairment as defined by the World Health Organization (WHO) (VA worse than 20/60-20/400 in the better eye) and the criteria used most commonly in the United States (VA worse than 20/40 but better than 20/200 in the better eye). Eligible subjects underwent an extensive ophthalmologic examination at The National University Hospital of Denmark. MAIN OUTCOME MEASURES: Best-corrected VA and primary causes of visual impairment. RESULTS: The prevalence of low vision according to the WHO definition ranged from 2.6% in subjects aged 70 to 74 years to 4.8% in subjects 75 to 80 years of age, with an age-adjusted relative prevalence of 1.58%. Using the U.S. definition, the overall age-adjusted prevalence of visual impairment was 2.9%. The causes of visual impairment according to the WHO criteria were age-related macular degeneration (AMD) (44.4%), cataract (33.3%), glaucoma in combination with cataract (11.1%), myopic macular degeneration (5.6%), and diabetic retinopathy (5.6%). However, according to the U.S. criteria, cataract was the most frequent primary cause (50.0%) and AMD was the second most frequent primary cause (34.4%) of visual impairment. Furthermore, using the U.S. criteria diabetic retinopathy was revealed as equally important as AMD and cataract as a cause of visual impairment among persons aged 65 to 69 years (33.3%). CONCLUSIONS: Increasing age was an independent predictor of visual impairment. Cataract and AMD were the leading causes. Adequate implementation of surgery to treat cataract could reduce visual impairment by 33.3% according to the WHO criteria and by 50% according to the U.S. criteria.     

Visual acuity and ocular diseases in aged residents of nursing homes: study of 219 persons in Orléans]

PURPOSE: To measure the visual acuity and to determine the etiological causes of visual impairment in the elderly residing in nursing homes. METHODS: 219 elderly persons residing in nursing homes were examined in the residence. The ophthalmological examination consisted in a visual acuity measurement, a slit-lamp examination and a fundus examination. RESULTS: This study included 145 women and 74 men. Mean age was 79.1 years (range 41-101 years). Visual acuity could be measured in 181 subjects (82.6%): it was 1/10 or worse in the better eye in 23 of them (13%) and 2/10 to 3/10 in 36 patients (20%). In 21 (17.6%) out of the 119 patients aged over 74 years, visual acuity was 1/10 or worse in the better eye. Visual impairment significantly increased with age (p < 0.05). There was no difference between men and women in the prevalence of visual impairment. Among the 55 subjects with visual impairment, the main causes of vision loss were: cataract in 36 patients (66%), age-related macular degeneration in 9 patients (16%) and optic neuropathies in 5 patients (9%). Only one (2.8%) out of the 36 patients with cataract could be operated. CONCLUSION: The rate of visual impairment of people in nursing homes was higher than in corresponding age groups in the general population. The main cause of vision loss was cataract; however, only a few patients could benefit from an operation. These results confirmed that a systematic ophthalmologic examination should be performed before general health problems prevent patients from being operated.     

Prevalence of visual impairment, blindness, and cataract surgery in the Hong Kong elderly

BACKGROUND: The prevalence of vision impairment, unilateral/bilateral blindness, and cataract surgery were estimated in a population based survey among the elderly in a suburban area of Hong Kong. METHODS: 15 public, private, and home ownership scheme housing estates in the Shatin area of Hong Kong were subjected to cluster sampling to randomly select a cross section of people 60 years of age or older. Visual acuity measurements and ocular examinations were conducted at a community site within each estate. The principal cause of reduced vision was identified for eyes with presenting visual acuity worse than 6/18. RESULTS: A total of 3441 subjects from an enumerated population of 4487 (76.7%) completed an eye examination. The prevalence of presenting visual acuity less than 6/18 in at least one eye was 41.3%; and 73.1% in those 80 years of age or older. Unilateral blindness (acuity <6/60) was found in 7.9% of subjects and bilateral blindness in 1.8%. Refractive error and cataract were, respectively, the main causes of vision impairment and blindness. Visual impairment with either eye <6/18 increased with advancing age and was more prevalent in males, the less educated, and those living in public housing estates. The prevalence of cataract surgery was 9.1% and was associated with advancing age and less education. CONCLUSIONS: Blindness and visual disability were common in this socioeconomically advanced population, with most of it easily remedied. Because of a rapidly ageing population, healthcare planners in Hong Kong must prepare for an increasing burden of visual disability and blindness.     

Age-specific prevalence and causes of bilateral and unilateral visual impairment in older Australians: the Blue Mountains Eye Study

Purpose : To report age‐specific prevalence and causes of bilateral and unilateral visual impairment in a representative older Australian population. Methods : Participants in the Blue Mountains Eye Study (n = 3654) underwent a detailed eye examination. Any visual impairment was defined as best‐corrected visual acuity (VA) of 6/12 or worse, moderate impairment as VA 6/24–6/60 and severe impairment as VA worse than 6/60 (the Australian definition for legal blindness). Bilateral visual impairment was defined from the better eye and unilateral impairment from the worse eye. Proportional causes for visual loss were determined by the examining ophthalmologist. Results : Prevalence of bilateral and unilateral visual impairment was strongly age related. Corresponding bilateral and unilateral visual impairment prevalence rates were, respectively, 0.6% and 3.6% for persons aged 49–59 years, 1.1% and 8.2% for ages 60–69, 5.4% and 20.1% for ages 70–79, and 26.3% and 52.2% for persons aged 80+ years. Overwhelmingly, age‐related maculopathy (ARM) was the predominant cause of bilateral blindness (13/17) and of moderate to severe bilateral visual impairment in persons aged 70+ years. However, cataract was the most frequent cause of mild bilateral visual impairment among persons aged 60+ years. Amblyopia was the most frequent cause of mild or worse unilateral visual impairment in persons aged 49–59 years. Cataract was the most common cause of mild unilateral visual impairment in people aged 60+ years, while ARM and cataract were jointly the most frequent causes of moderate to severe unilateral visual impairment in people aged 70+ years. Conclusions : These findings indicate that around half of visually impaired persons aged 60 years or over had cataract, a cause amenable to treatment.     

Unilateral visual impairment in an urban population in southern India

This study assessed the prevalence and causes of unilateral visual impairment in the urban population of Hyderabad city as part of the Andhra Pradesh Eye Disease Study. Stratified, random, cluster, systematic sampling was used to select 2,954 subjects from 24 clusters representative of the population of Hyderabad. Eligible subjects underwent detailed eye examination including logMAR visual acuity, refraction, slitlamp biomicroscopy, applanation tonometry, gonioscopy, dilatation, cataract grading, and stereoscopic evaluation of fundus. Automated threshold visual fields and slitlamp and fundus photography were done when indicated by standardised criteria. Unilateral visual impairment was defined as presenting distance visual acuity < 6/18 in the worse eye and > or = 6/12 in the better eye, which was further divided into unilateral blindness (visual acuity < 6/60 in the worse eye) and unilateral moderate visual impairment (visual acuity < 6/18-6/60 in the worse eye). A total of 2,522 subjects (85.4% of eligible), including 1,399 > or = 30 years old, participated in the study. In addition to the 1% blindness and 7.2% moderate visual impairment (based on bilateral visual impairment criteria) reported earlier in this sample, 139 subjects had unilateral visual impairment, an age-gender-adjusted prevalence of 3.8% (95% confidence interval 2.7-4.9%). The major causes of this visual impairment 39.9% were refractive error (42.9%), cataract (14.4%), corneal disease (11.5%), and retinal disease (11.2%). Of this unilateral visual impairment was blindness. The major causes of unilateral blindness were corneal disease (23.2%), cataract (22.5%), retinal disease (18%), and optic atrophy (12.9%). On the other hand, the predominant cause of unilateral moderate visual impairment was refractive error (67%) followed by cataract (9%). Of the total unilateral visual impairment, 34.3% was present in those < 30 years old and 36.2% in those 30-49 years old. Unilateral visual impairment afflicts approximately 1 in 25 persons in this urban population. A large proportion of this unilateral visual impairment is present in younger age groups. The causes of unilateral visual impairment, like those of bilateral visual impairment in this population, are varied, suggesting therefore, that in addition to the current focus of eye care in India predominantly on cataract, other causes of visual impairment need to be addressed as well.     

Visual Impairment in Diabetes

Visual acuity was measured in a population-based study of diabetic retinopathy in southern Wisconsin. Persons diagnosed prior to 30 years of age and taking insulin (younger onset, n = 996) and those diagnosed at 30 years of age or older (older onset, n = 1370) were examined. Best corrected visual acuity was determined using the Early Treatment of Diabetic Retinopathy Study protocol. In the younger onset group, 1.4% had moderate visual impairment (best corrected visual acuity in the better eye of 20/80 to 20/160) and 3.6% were legally blind (visual acuity in the better eye of 20/200 or worse). Visual impairment in this group was associated with older age at examination, longer duration of diabetes, presence of proliferative retinopathy, and presence of senile cataracts. In the older onset group, 3.0% had moderate visual impairment and 1.6% were legally blind. Visual impairment in this group was associated with older age at examination, longer duration of diabetes, presence of senile cataract, presence of macular edema, and proliferative diabetic retinopathy. When assigning causes of impaired vision, diabetic retinopathy was responsible in part for 86% of eyes with visual acuity of 20/200 or worse in younger onset persons and for 33% in older onset persons.     

Incidence of visual impairment and blindness in indigenous Australians within Central Australia: the Central Australian Ocular Health Study

Background: To estimate the incidence and causes of visual impairment and blindness among indigenous Australians living in Central Australia. Design: Clinic‐based cohort study. Participants: A total of 1884 individuals aged ≥20 years living in one of 30 remote communities within the statistical local area of ‘Central Australia’. Methods: From those initially recruited, 608 (32%) participants were reviewed again between 6 months and 3 years (median 2 years). Patients underwent Snellen visual acuity testing and subjective refraction. Following this, an assessment of their anterior and posterior segments was made. Baseline results were compared with those who were reviewed. Main Outcome Measures: The annual incidence rates and causes of bilateral visual impairment (vision worse than Snellen visual acuity 6/12 in the better eye) and bilateral blindness (Snellen visual acuity worse than 6/60 in the better eye). Results: The annual incidence of bilateral visual impairment and blindness was 6.82% (8.12% for those aged ≥40 years) per year and 0.50% (0.62% for those aged ≥40 years) per year, respectively. Refractive error, followed by cataract and diabetic retinopathy, were the main causes for incident bilateral visual impairment and blindness. Conclusion: This study has demonstrated rates of incident bilateral blindness and visual impairment among the indigenous Australian population within Central Australia, which are substantially higher than those from the non‐indigenous population. Services need to address the underlying causes of this incident vision loss to reduce visual morbidity in indigenous Australians living in central Australia.     

Prevalence and causes of visual impairment in The Barbados Eye Study

OBJECTIVE: To determine the prevalence and causes of low vision and blindness in a predominantly black population. DESIGN: Population-based prevalence study of a simple random sample of Barbados-born citizens aged 40 to 84 years. PARTICIPANTS: Four thousand seven hundred nine persons (84% participation). METHODS: The standardized protocol included best-corrected visual acuity (with a Ferris-Bailey chart), automated perimetry, lens gradings (LOCS II), and an interview. Participants with visual acuity of worse than 20/30, other positive findings, and a 10% sample also had an ophthalmologic examination that evaluated the cause and extent of vision loss (resulting from that cause), if any. MAIN OUTCOME MEASURES: Low vision and blindness were defined as visual acuity in the better eye between 6/18 and 6/120 and visual acuity worse than 6/120, respectively (World Health Organization [WHO] criteria). RESULTS: Of the 4631 participants with complete examinations, 4314 (93%) reported their race as black, 184 (4%) reported their race as mixed (black and white), and 133 (3%) reported their race as white or other. Low vision was found in 5.9% of the black, 2.7% of the mixed, and 3.0% of white or other participants. Bilateral blindness was similar for black and mixed race participants (1.7% and 1.6%, respectively) and was not found in whites. Among black and mixed participants, the prevalence of low vision increased with age (from 0.3% at 40-49 years to 26.8% at 80 years or older). The prevalence of blindness was higher (P < 0.001) for men than women at each age group (0.5% versus 0.3% at ages 40-49 and 10.9% versus 7.3% at 80 years or more). Sixty percent of blindness was due to open-angle glaucoma and age-related cataract, each accounting for more than one fourth of cases. Other major causes were optic atrophy or neuropathy and macular and other retinal diseases. Few cases of blindness were due to diabetic retinopathy (1.4%), and none were due to age-related macular degeneration. CONCLUSIONS: Using the WHO criteria, prevalence of visual impairment was high in this African-origin population, particularly at older ages. Most blindness was due to open-angle glaucoma and cataract, with open-angle glaucoma causing a higher proportion of blindness than previously reported. The increased prevalence of blindness in men may be due to the increased male prevalence of glaucoma in this population and warrants further investigation. Results underline the need for blindness prevention programs, with emphasis on effective treatment of age-related cataract and enhancing strategies for early detection and treatment of open-angle glaucoma.     

Causes of visual impairment in two older population cross-sections: The Blue Mountains Eye Study

AIMS To describe the causes of bilateral and unilateral blindness and visual impairment in two cross-sections of an older Australian population 6 years apart. METHODS The Blue Mountains Eye Study examined 3654 persons aged 49-97 years during 1992-1994 (population cross-section 1). Cohort survivors (2335) and 1174 persons who moved to the area or reached an eligible age were examined during 1997-2000, a total of 3509 persons (population cross-section 2). LogMAR visual acuity was measured after standardized refraction. Blindness and visual impairment were respectively defined by visual acuity &lt;6/60 and &lt;6/12. Causes were determined for the two temporal cross-sections. RESULTS Age-related macular degeneration (AMD) was the principal cause of bilateral and unilateral non-correctable blindness in both cross-sections. AMD caused 77% of bilateral blindness in Cross-section 1 and 50% in Cross-section 2. Cataract, glaucoma, corneal and neurological disease were next equally frequent causes (6% each) of bilateral blindness in Cross-section 1. In Cross-section 2, cataract ranked as the third most frequent principal cause (10%) after other retinal diseases (40%). The proportion of unilateral blindness with AMD as principal cause was very similar (around one-third of cases) in the two cross-sections; while in Cross-section 2 blindness was less frequently caused by cataract (19% vs. 13%). Cataract was the principal cause of both bilateral and unilateral visual impairment, responsible for 50% of bilateral (better eye) and 35-40% of unilateral (worse eye) impairment, with slightly lower rates found in Cross-section 2 than in Cross-section 1. AMD was consistently the second most frequent cause, causing one-third of bilateral and one-fifth of unilateral visual impairment. CONCLUSIONS These data indicate a relative stable pattern of causes for blindness and visual impairment, with AMD and cataract, respectively, dominating these two levels.     

The prevalence and causes of bilateral and unilateral blindness in an elderly urban Danish population. The Copenhagen City Eye Study

PURPOSE: To study the prevalence and causes of bilateral and unilateral blindness in an elderly urban Danish population. METHODS: Data originated from a Danish epidemiologic cross-sectional random sample population eye survey conducted during the years 1986-1988. The population consisted of 1,000 inhabitants aged 60 to 80 years in Copenhagen. The participants underwent an extensive ophthalmologic examination. A participation rate of 96.9% was achieved. Any blindness was defined as best-corrected visual acuity (VA) worse than 0.05 (the WHO criteria) and VA of 0.1 or worse (the National criteria (NC) of blindness). RESULTS: The prevalence rates of bilateral and unilateral blindness were, respectively, 0.53% and 3.38% according to WHO, but 1.06% and 4.44% using NC. Bilateral blindness rose significantly with age (p=0.02). According to NC, age-related macular degeneration (AMD) was the leading cause of bilateral blindness, accounting for 60% of all blind persons. Glaucoma, myopic macular degeneration, cataract and retinitis pigmentosa were jointly the second most common cause, each accounting for 10% of all bilaterally blind persons. Diabetic retinopathy was not a cause of bilateral blindness. Amblyopia was the most frequent, AMD the second most frequent, and diabetic retinopathy was among the third most common cause of unilateral blindness accounting for, respectively, 28.60%, 16.66% and 9.52% of all unilateral blindness. CONCLUSIONS: Blindness was associated with increasing age. A calculation indicates that among Danes aged 60 to 80 years 7,736 are bilaterally blind and 35,503 suffer from unilateral blindness. This study highlights AMD as the most important cause.     

Prevalence and causes of visual impairment in an elderly Chinese population in Taiwan: the Shihpai Eye Study

OBJECTIVE: Few population-based data on the prevalence and causes of visual impairment are available from East Asia. The purpose of this study was to determine the prevalence and causes of visual impairment in an elderly Chinese population in Taiwan. DESIGN: Population-based cross-sectional study. PARTICIPANTS: The Shihpai Eye Study was a survey of vision and ocular disease among an elderly Chinese population 65 years of age or older residing in Shihpai, Taiwan. A random sample of 2045 elderly residents was identified and selected from the household registration databank. Among them, 1361 (66.6%) underwent a detailed ophthalmic examination. METHODS: The ophthalmic examination included best-corrected visual acuity measurements using standardized protocols. Visual acuity was assessed with a Snellen E chart. The major cause of visual loss was identified for all participants who were visually impaired. MAIN OUTCOME MEASURES: Low vision and blindness were defined as a best-corrected visual acuity in the eye with better vision worse than 20/60 to a lower limit of 20/400 and worse than 20/400, respectively, according to World Health Organization categories of visual impairment. RESULTS: The mean age of the participants was 72.2 (range, 65-91) years old. A total of 40 participants met the World Health Organization criteria of low vision, and 8 were diagnosed as blind. The rate of blindness and low vision was estimated to be 0.59% (95% confidence interval, 0.25%, 1.16%) and 2.94% (95% confidence interval, 2.11%, 3.99%), respectively. There was a significant increase in the rate of low vision (P<0.001) from 0.83% at 65 to 69 years of age to 8.33% at age 80 years or older. There was no gender difference in the prevalence of blindness or low vision. The leading cause of visual impairment was cataract (41.7%), followed by myopic macular degeneration (12.5%) and age-related macular degeneration (10.4%). CONCLUSIONS: The rate of blindness and low vision is close to that reported for other developed countries. The high frequency of myopic macular degeneration as a major cause of visual loss, however, is not observed in European-derived populations. Specific prevention or low-vision rehabilitation programs should be developed for the elderly Chinese population.     

The Sivaganga Eye Survey: I. Blindness and cataract surgery

PURPOSE To assess the prevalence of visual acuity impairment, blindness, and cataract surgery among older adults in rural southern India. METHODS Random selection of village- and urban-based clusters was used to identify a cross-sectional sample of persons 50 years of age or older from the Sivaganga district of Tamil Nadu. Subjects in 25 selected clusters were enumerated through a door-to-door survey and invited to examination sites for measurement of uncorrected, presenting, and best-corrected visual acuity and ocular examination in 1999. The principal cause was identified for eyes with presenting visual acuity worse than 6/18. Quality assurance monitoring of visual acuity measurements took place in five of the study clusters. RESULTS A total of 5081 persons in 3517 households were enumerated, and 4642 (91.4%) were examined. Thirty-six percent presented with visual acuity worse than 6/18 in the better eye. The prevalence of blindness, based on visual acuity worse than 6/60 in both eyes, was 6.0% (95% confidence interval [CI]: 5.1% to 6.9%) with presenting vision, and 2.5% (95% CI: 1.8% to 3.1%) with best correction. Blindness with presenting visual acuity was associated with older age and illiteracy. Cataract was the principal cause of blindness in one or both eyes in 69.4% of those presenting blind, and uncorrected aphakia and other refractive error affected 35.6% in at least one eye. The prevalence of cataract surgery was 14.7% (95% CI: 13.0% to 16.4%); low surgical coverage among the cataract blind was associated with illiteracy. CONCLUSION It appears that much has been done in the prevention of blindness in Sivaganga. Nevertheless, blindness remains an important public health problem, mainly because of cataract and refractive error. Prevention of blindness programs in the area should target these two causes, with special emphasis on the elderly and the illiterate.     

The Beaver Dam Eye Study: visual acuity

Few current population-based data on visual impairment are available. Visual acuity and impairment were measured in 4926 people between the ages of 43 and 86 years in the defined population participating in the Beaver Dam Eye Study. Visual acuity was measured after refraction, using standardized protocols. Of a possible maximum score of 70 (20/10), the mean number of letters correctly identified (right eye) varied from 55.7 (20/20, n = 1515) in people between the ages of 43 and 54 years to 41.2 (20/40, n = 795) in people 75 years of age or older. Age-specific mean visual acuity scores were consistently and significantly lower in women, who identified three fewer letters on the average than men. Rates of any visual impairment (20/40 or worse in the better eye) or legal blindness (20/200 or worse in the better eye), increased from 0.8% and 0.1%, respectively, in people between the ages of 43 and 54 years to 21.1% and 2.0%, respectively, in people 75 years of age or older. Multivariate analyses showed both sex (women) and age (older) to be significant and independent predictors of poorer visual acuity.     

Prevalence and causes of visual impairment and blindness in Sistan-va-Baluchestan Province, Iran: Zahedan Eye Study

AIM: To determine the prevalence and causes of visual impairment and blindness in the Sistan-va-Baluchestan Province of Iran. METHODS: A population-based cross-sectional study with a multistage cluster sampling technique was used to identify the study subjects. Visual acuity (VA) was defined for all participants aged >or=10 years. Participants with a VA of <20/60 were examined by an ophthalmologist to determine the causes of low vision or blindness. RESULTS: 5446 (84.0%) of the invited people were examined. The prevalence of visual impairment (VA <20/60) was 6.81% (95% CI 5.91% to 7.71%) and of bilateral blindness (VA <3/60) was 0.79% (95% CI 0.50% to 1.08%). Visual impairment increased with age and illiteracy. Bilateral blindness doubled in women aged >40 years. The causes of visual impairment and blindness were cataract (37.7%), corneal opacity (15.0%), amblyopia (15.0%), glaucoma (5.7%) and hyperopia (5.0%). 39.5% of the visual impairment cases were potentially curable. CONCLUSION: The estimated magnitude of visual impairment and blindness was much higher than our expectations. Further investigation of the pattern of vision loss in women and children, particularly as a result of trachoma and amblyopia, is warranted. Implementation of measures to treat curable cases of the study population can improve the situation in the region dramatically.     

温州市社区老年眼病筛查报告之一：视力损伤及年龄相关性白内障筛查与转诊情况

目的调查温州市区50岁及以上社区人群年龄相关性白内障患病及中重度视力损伤及后续转诊情况。方法调查研究。在2014年3月至2016年1月期间根据自愿原则,对温州市区124个社区共31 170例50岁及以上人群进行眼病筛查,包括生活视力、眼压、裂隙灯显微镜和眼底照相。对于视力下降至0.3或以下,存在明显白内障或其他眼病的受检者建议转诊。采用χ2检验或趋势χ2检验进行数据分析。结果31 170例受检者中,检出年龄相关性白内障10 023例,检出率为32.16%,随年龄增长,白内障的检出率增高（趋势χ2=4049.64,P＜0.01）。各年龄组中,女性人群白内障检出率均高于男性（50～59岁：χ2=8.70,P＜0.01;60～69岁：χ2=46.78,P＜0.01;70～79岁：χ2=52.21,P＜0.01;≥80岁：χ2=32.26,P＜0.01）。中度视力损伤（双眼中较差眼日常生活视力<0.3且≥0.1,较好眼视力≥0.1） 5 657例,检出率为18.15%;单眼盲和重度视力损伤（双眼中较差眼生活视力＜0.1,较好眼≥0.1） 2 161例,检出率为6.93%;双眼盲和重度视力损伤（双眼日常生活视力＜0.1） 604例,检出率为1.94%。随年龄增长,中度视力损伤（趋势χ2=217.14,P＜0.01）、单眼盲和重度视力损伤（趋势χ2=165.14,P＜0.01）以及双眼盲和重度视力损伤（趋势χ2=57.58,P＜0.01）的检出率明显增高。白内障患者中较好眼视力＜0.3者1 398例,占白内障总人数的13.95%,其中1 061例（75.90%）受检者接受转诊治疗卡表示愿意至医院就诊,最终有449例至眼视光医院检查并接受手术治疗,转诊率为32.12%。结论温州市区50岁及以上社区人群中视力损伤及白内障的检出率较高,社区人群仍缺乏视觉健康意识,应加强眼病相关知识的宣教工作。     

2009年上海市宝山区大场社区60岁及以上人群盲和低视力患病率调查

目的 探讨上海市宝山区大场社区60岁及以上人群的盲和低视力患病率、致盲原因及其相关因素。方法 横断面现况调查研究。由上海市眼病防治中心和上海市宝山区疾病预防控制中心于2009年10至12月期间对上海市宝山区大场社区60岁及以上并在当地居住10年以上的常住户籍人口进行随机整群抽样调查。对调查对象完成视力、眼压、验光、裂隙灯显微镜、免散瞳数字眼底照相等检查,采用世界卫生组织视力损伤标准和日常生活视力和视力损伤标准确立盲或低视力,并明确主要致盲原因。组间率的比较采用卡方检验。结果 实际受检4545人,受检率为87.42％。受检人群均为近10年内随着城市化进程从原农村人口转变而来的城市人口。按照世界卫生组织视力损伤标准：双眼盲30人,患病率0.67％;双眼低视力145人,患病率3.19％。白内障、黄斑变性、眼球萎缩或缺如、青光眼、糖尿病视网膜病变（或角膜病）是前5位致盲眼病。女性低视力患病率高于男性,差异有统计学意义(x2 =4.88,P＜0.05)。按照日常生活视力和视力损伤标准：双眼盲39人,患病率0.86％,双眼低视力401人,患病率8.82％;75岁后成为视力损害的高速发展期。白内障、未矫正的屈光不正、黄斑变性、眼球萎缩或缺如、青光眼是前5位致盲原因。女性低视力患病率高于男性,差异有统计学意义(x2=13.345,P＜0.01)。结论 在上海市城市化进程较快的老龄化社区中,白内障、未矫正的屈光不正、黄斑变性是引起日常生活视力盲的前3位原因,女性低视力患病率明显高于男性。对这类社区居民需要进行更多的有针对性眼的保健教育与服务工作。     

Visual impairment in the 40- to 64-year-old population of Shahroud, Iran

Purpose

To determine the prevalence of visual impairment by age and gender in Shahroud.

Methods

Using random cluster sampling, 6311 Shahroud inhabitants who were between 40 and 64 years old were invited for ophthalmological examinations. Visual acuity worse than 0.5 LogMAR (20/60) and 1.3 LogMAR (20/400) in the better eye was regarded as low vision and blindness, respectively. The cause of blindness was determined by an ophthalmologist and in a person with more than one cause, the most correctable cause was regarded as the main cause.

Results

This study was conducted on 5190 participants (response rate: 82.2%). On the basis of presenting visual acuity, the prevalence of low vision and blindness was found to be 1.8% (95% confidence interval (CI): 1.4–2.10) and 0.5% (95% CI: 0.3–0.7), respectively. Based on corrected vision, these values were 0.5% (95% CI: 0.3–0.7) and 0.3% (95% CI: 0.1–0.4), respectively. Visual impairment increased with age in women (P<0.001). Uncorrected refractive errors (63.9%), cataract (20.2%), and amblyopia (5.9%) were the most common causes of visual impairment based on presenting vision. Based on corrected vision, however, cataract (42.5%), amblyopia (12.5%), and retinitis pigmentosa (7.5%) were the most common causes of visual impairment.

Conclusion

Although the prevalence of visual impairment in the city of Shahroud was determined to be lower than two previous studies in the country, correction of refractive errors and cataract could minimize the rate of visual impairment in this population as they were shown to comprise 85% of the causes of visual impairment. The elderly women need to receive more attention.     

Causes of blindness and visual impairment in a population-based sample of U.S. Hispanics

OBJECTIVE: To describe the causes of blindness and visual impairment in a population-based sample of Hispanics. DESIGN: A cross-sectional study. PARTICIPANTS: A random sample of 4774 Hispanic residents of Santa Cruz and Pima Counties in Southern Arizona aged 40 years and older who participated in Proyecto VER (Vision Evaluation and Research). TESTING: Subjects were interviewed and underwent a thorough ophthalmic examination. Presenting and best-corrected visual acuity was determined using the Early Treatment of Diabetic Retinopathy Study protocol, followed by a standardized ophthalmic examination to determine the causes of visual loss. Anterior and posterior segment specialists in ophthalmology confirmed the causes. MAIN OUTCOME MEASURES: Causes of visual loss (best-corrected acuity worse than 20/40). RESULTS: The response rate of eligible participants was more than 70%. Best-corrected acuity in the better seeing eye worse than 20/40 increased from 0.3% in those aged 40 to 49 to 5.6% in those aged 65 and older. The leading cause was cataract, accounting for 42% of all visual loss, followed by age-related macular degeneration (15%), and diabetic retinopathy (13%). Among 14 people who were bilaterally blind, open-angle glaucoma was the leading cause. Women had higher age-adjusted prevalence of severe cataract compared with men and were more likely to be visually impaired from cataract, diabetic retinopathy, and open-angle glaucoma, although gender differences were not statistically significant. CONCLUSIONS: Causes of visual impairment differ from those reported in Caucasian populations, with open-angle glaucoma being the leading cause of blindness. Further work on gender-based obstacles to eye care in the Hispanic community may be warranted.     

Five-year change in visual acuity and incidence of visual impairment: the Blue Mountains Eye Study

PURPOSE: To describe the 5-year change in visual acuity and the incidence of visual impairment in a population-based cohort. DESIGN: Population-based epidemiologic study. PARTICIPANTS: Of the 3654 participants of the Blue Mountains Eye Study (BMES I) baseline examination (aged 49 years+ during 1992-1994), 2335 were reexamined during the 5-year follow-up examinations from 1997 to 1999 (BMES II), and 543 persons had died since BMES I. METHODS: Visual acuity was measured using a logarithm of the minimum angle of resolution chart in both eyes separately before and after standardized refraction. Pupils were dilated and a detailed examination was performed. MAIN OUTCOME MEASURES: Visual impairment, after best refractive correction, was defined as any (visual acuity 20/40 in both eyes at baseline. Incident binocular severe visual impairment was defined as visual acuity 20/200 in both eyes at baseline. The incidence for three other levels of visual impairment is also given: <20/40, <20/70, and <20/200. Monocular visual impairment was defined as impairment in one eye only at follow-up, where both eyes were unimpaired at baseline. Incident doubling and halving of the visual angle were calculated. RESULTS: Incidence rates for visual impairment increased significantly with age. Any incident impairment 相似文献   

南通市新城桥街道60岁及以上人群盲和低视力的现况调查

目的调查江苏省南通市城市人口中60岁及以上人群盲和低视力的患病率及其原因。方法采用随机整群抽样方法,抽取新城桥街道14个社区中的8个,并对所有60岁及以上人群进行检查。分别检查小孔视力和日常生活视力,应用裂隙灯显微镜和直接检眼镜等仪器检查受检者外眼、眼前节及眼底等情况。正式调查前先进行预试验。结果共检录3352人,受检人数为3040人,应答率90．69％。按小孔视力和世界卫生组织视力损伤标准,双眼盲和低视力患病率分别为1．35％和1．84％,其中女性分别为1．92％和2．33％,男性为0．66％和1．24％;盲和低视力患病率随着年龄的增长而增加;致盲和低视力的首要原因为白内障。按日常生活视力和视力损伤标准,双眼盲和视力损伤的患病率分别为1．58％和13．59％,其中女性分别为2．10％和15．98％,男性为0．95％和10．66％;盲和视力损伤的患病率亦随年龄的增长而增加;致双眼盲的首要原因亦为白内障。结论南通市60岁及以上城市人群盲的患病率低于华北、华南及西部地区。女性与文盲的盲和低视力患病率分别高于男性与非文盲。南通市城市人口中致盲的主要原因依次为白内障、眼底异常、屈光不正及角膜瘢痕或混浊等。