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。     

乌鲁木齐市老年公寓中50岁及以上人群盲与低视力调查

目的了解乌鲁木齐市19所正式登记的老年公寓入住50岁及以上人群的盲与低视力构成比及主要致盲原因。设计横断面调查。研究对象乌鲁木齐市19所老年公寓中50岁及以上符合入选标准的475人。方法对符合此次调查准入标准的475人进行常规日常生活视力、小孔视力的检查。筛选出盲和低视力的患者,对其眼病进行相应辅助检查,分析致盲的主要原因。主要指标盲与低视力构成比。结果被调查的475人中,按照A标准:双眼盲构成比为6.9%,双眼低视力的构成比为8.4%,单眼盲构成比为14.9%,单眼低视力构成比为12.0%。按照B标准:视力损伤构成比为17.1%,单眼盲、轻度盲和重度盲构成比分别为15.4%、2.9%和6.9%。致盲的主要病因依次为白内障(59.87%)、屈光不正(11.84%)、眼底病变(15.13%)、角膜混浊(5.92%)、眼球萎缩或缺如(2.96%)、青光眼(2.63%)、不确定(1.64%)。结论乌鲁木齐市老年公寓50岁及以上人群,随年龄增加易患致盲性眼病。白内障为主要致盲原因。     

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。     

海南省盲和低视力流行病学调查

对海南省３３６００人，进行了盲和低视力流行病学调查，海南省双眼盲患病率为０．７６％，单眼盲患病率为０．７１％，双眼低视力患病率为０．７３％，单眼低视力患病率为０．５０％，盲和低视力的患病率都随年龄增长而递增，双，单眼盲和低视力都是女性明显高于男性，致盲病因中，双单眼盲部都以白内障最多。其次双眼盲以青光眼，单眼盲以角膜病，眼外伤最多，双眼盲２５４人中有１８３人可以治疗，占７２％，单眼盲２４０人中有１     

上海市北新泾街道60岁及以上人群盲和视力损伤的现况调查

目的 调查上海市北新泾街道60岁及以上老年人低视力、盲的患病率及致盲原因,并与以前调查结果相比较,评价近年该地区实施防盲治盲项目的 效果.方法 应用横断面研究的流行病学调查方法.由上海交通大学附属第一人民医院和上海市长宁区北新泾社区卫生服务中心于2007年11月至2008年4月采用整群随机抽样方法在上海市长宁区北新泾街道抽取8个社区,对其中所有的60岁及以上老年人进行调查,检查日常生活视力和针孔镜矫正视力,应用裂隙灯显微镜、直接检眼镜和眼底照相机等仪器检查受检者外眼、眼前节及眼底等情况.观察低视力及盲的患病情况,分析致盲的主要原因.正式调查前先进行预试验,通过计算kappa值进行不同检查者诊断结果的重复性检验,保证调查质量.结果 在应检录4153人中,受检人数为3851人,受检率为92.73%.按照世界卫生组织视力损伤标准:双眼盲29人,其中男性11人(占37.93%)、女性18人(占62.07%).双眼低视力104人,其中男性37人(占35.58%)、女性67人(占64.42%).双眼盲和双眼低视力的患病率分别为0.75%和2.70%.致盲的主要原因依次为:黄斑变性、白内障、角膜瘢痕或混浊及视网膜脱离.按照日常生活视力和视力损伤标准:重度双眼盲61人,其中男性20人(占32.79%)、女性41人(占67.21%).轻度双眼盲66人,其中男性27人(占40.91%)、女性39人(占59.09%).单眼盲276人,其中男性120人(占43.48%)、女性156人(占56.52%).重度双眼盲、轻度双眼盲、单眼盲的患病率分别为1.58%、1.71%和7.17%.致盲的主要原因依次为:黄斑变性、白内障、屈光不正及角膜瘢痕或混浊.结论 黄斑变性仍是致盲的首要原因,眼底病患病率逐渐上升,社区防盲项目已初显成效.     

黄山市徽州区盲及低视力调查与治疗

目的调查黄山市徽州区盲及低视力的患病率。方法根据ＷＨＯ的盲及低视力分级标准,采取５０岁以上人群逐一登记检查,中小学在校学生集中检查,其它人群采取主动报病及线索调查的方法。先由村级、乡级进行初步调查,然后由区防盲小组负责进行定盲检查并登记造册。结果全区９８７３７人,实际调查了９４５７０人,受检率为９６．５％。结果显示我区双盲患病率为０．３１％,单盲０．１７％,双眼低视力０．１２％,单眼低视力０．０９％。主要致盲原因为白内障,并且主要集中在５０岁以上人群。并在此基础上进行了以白内障复明手术为主的治疗。结论通过全区的盲及低视力流行病学调查,了解我区致盲原因及分布情况,为我区进一步开展防盲治盲工作指出了重点和方向     

我国白内障的流行病学调查资料分析

目的 探讨我国白内障的患病率与各地检查条件、诊断标准及地理环境的关系。方法 采用世界卫生组织盲与低视力标准,对全国抽样调查资料进行统计学分析。结果 双眼视力〈０．３的白内障患者约５００万人,患病率为０．４６％;盲与低视力的患病率分别为０．４３％和０．５８％。盲人中白内障致盲占４１．０６％;低视力患者中４９．３８％为白内障所致;白内障致老年盲（年龄≥６０岁）及低视力占７３．１３％。以晶体混及视力〈０     

上海市金山区廊下镇老年人盲和低视力流行病学研究

目的研究上海市金山区廊下镇60岁及以上人群的盲和低视力患病率、致盲病因及其相关因素。方法对目标人群进行整群抽样。对调查对象完成视力、眼压、验光、裂隙灯、免散瞳数字眼底照相等检查,采用最佳矫正视力和日常生活视力及其视力损伤标准确立盲或低视力,并明确主要病因。结果本研究实际受检2150人,受检率为80.95%。按照最佳矫正视力损伤标准分类:双眼盲35例,患病率为1.63%;双眼低视力176例,患病率8.18%,白内障、黄斑变性、角膜病、眼球萎缩或缺如、糖尿病视网膜病变是前五位主要病因;女性盲患病率(2.10%)高于男性(0.86%),差异有统计学意义(P<0.05)。按照日常生活视力损伤标准分类:双眼盲43例,患病率为2.00%;双眼低视力467例,患病率为21.72%;女性低视力患病率(8.99%)高于男性(7.00%),差异有统计学意义(P<0.05);白内障、未矫正的屈光不正、黄斑变性、角膜病、眼球萎缩或缺如是前五位主要病因。结论对于上海农村地区的老年人,必须通过加强白内障复明手术的实施、屈光不正的矫正、眼底退变性疾病的筛查和干预来提高防盲治盲的效率。     

广西合浦县白内障致盲及低视力的调查

目的调查广西合浦县白内障致盲及低视力的患病率及白内障手术负荷量。方法 2006年对广西合浦县4个乡镇8个自然小区人群进行检查。双眼视力〈0.05者为白内障盲人,〈0.3者为白内障低视力患者,〈0.1者为白内障手术对象。结果调查人群3270人,实检人数2800人,受检率为85.6%。白内障致盲率为1.89%,低视力患病率为2.71%,白内障手术负荷量为2.18%。结论广西合浦县白内障致盲率及低视力患病率较高,白内障手术复明是目前防盲治盲的首要任务。     

广东省梅县盲和低视力流行病学调查

目的 调查梅县盲及低视力的流行病学情况。方法 采用分层随机抽样原因,以世界卫生组织盲目分级为标准,对全县按2.01%抽样比例抽取11327例进行盲和低视力的流行病学调查。结果 双眼盲及低视力患病率分别为0.47%（男性0.30%,女性0.63%）和0.89%（男性0.66%,女性1.12%）;双眼盲率：县城0.29%、附城郊区0.34%、山区0.56%。单眼盲、双眼低视力和单眼低视力的患病率分别为0.72%、0.89%和0.59%。≥50岁盲及低视力患者的患病率明显增高。结论 致盲和致低视力的眼病均以白内障居首位,其次为青光眼、屈光不正、弱视及翼状胬肉等。     

Prevalence and causes of visual impairment in a rural North‐east China adult population: a population‐based survey in Bin County,Harbin

Acta Ophthalmol. 2010: 88: 669–674

Abstract.

Purpose: To investigate the prevalence and causes of visual impairment in a rural population in north‐east China. Methods: A population‐based study was conducted within Bin County, Harbin of north‐east China. Low vision and blindness were defined using the World Health Organization categories of visual impairment. The prevalence of visual impairment was estimated, and causes were identified based on best‐corrected visual acuity (BCVA) as well as presenting visual acuity (VA). Results: Out of 5764 people, 4956 (86.01%) aged older than 40 participated in the study. The prevalence of visual impairment, low vision and blindness based on presenting VA was 9.6% (BCVA, 6.6%), 7.7% (BCVA, 4.9%) and 1.9% (BCVA, 1.7%), respectively. Taking the presenting VA, cataract (44%) was the most common cause for visual impairment followed by uncorrected refractive error (24%), treatable causes of visual impairment accounted for 68% of the total cases. Cataract (59%) and glaucoma (15%) were leading causes for blindness based on presenting VA. According to BCVA, cataract was the leading cause of visual impairment and blindness (58% and 60%, respectively), followed by glaucoma (17% and 15%, respectively). The prevalence of visual impairment was higher among women than men (p < 0.0001) and increasing with age (p < 0.0001) and decreasing with increasing education level (p = 0.0075). Conclusion: Visual impairment was a serious public health problem in this rural population, with most of it easily remedied. Results highlighted the need for visual impairment prevention programs to an increasing number of elderly people, with a special emphasis on female and those with little or no education.     

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.     

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.     

Rapid assessment of avoidable blindness and needs assessment of cataract surgical services in Satkhira District, Bangladesh

AIMS: To estimate the magnitude and causes of blindness in people aged > or =50 years in Satkhira district, Bangladesh, and to assess the availability of cataract surgical services. METHODS: 106 clusters of 50 people aged > or =50 years were selected by probability-proportionate to size sampling. Households were selected by compact segment sampling. Eligible participants had their visual acuity measured. Those with visual acuity <6/18 were examined by an ophthalmologist. A needs assessment of surgical services was conducted by interviewing service providers. RESULTS: 4868 people were examined (response rate 91.9%). The prevalence of bilateral blindness was 2.9% (95% confidence interval (CI) 2.4% to 3.5%), that of severe visual impairment was 1.6% (95% CI 1.2% to 2.0%) and that of visual impairment was 8.4% (95% CI 7.5% to 9.3%). 79% of bilateral blindness was due to cataract. The cataract surgical coverage was moderate; 61% of people with bilateral cataract blindness (visual acuity <3/60) had undergone surgery. 20% of the 213 eyes that had undergone cataract surgery had a best-corrected poor outcome (visual acuity <6/60). The cataract surgical rate (CSR) in Satkhira was 547 cataract surgeries per million people per year. CONCLUSIONS: Although the prevalence of blindness and visual impairment was lower than expected, the CSR is inadequate to meet the existing need, and the quality of surgery needs to be improved.     

Rapid Assessment of Avoidable Blindness and Cataract Surgical Services in Kilimanjaro Region,Tanzania

Purpose: To estimate the prevalence and causes of avoidable blindness and visual impairment in persons 50 years of age and older, and to assess the impact of cataract surgical services.

Methods: In this cross-sectional population-based survey, 72 clusters of 50 people 50 years and older were selected by probability proportionate to size sampling. Households within clusters were selected through compact segment sampling. Participants underwent an ophthalmic examination in their homes, including measurement of visual acuity (VA) with a tumbling-E chart and diagnosis of the principal cause of visual impairment. Patients who had been operated on were questioned about details of their cataract surgery.

Results: Three thousand six hundred eligible subjects were selected, of whom 3,436 (95.5%) were examined. The prevalence of bilateral blindness (presenting VA < 3/60) was 2.4% (95% confidence interval [CI], 1.9%–2.9%); prevalence of severe visual impairment was 0.99% (95% CI, 0.98%–0.99%); and prevalence of visual impairment (VA of <?6/18 and ≥ 6/60) was 5.4% (95% CI, 4.6%–6.2%) in the sample. Unoperated cataract accounted for 52.4% of blindness and 70.6% of severe visual impairment. Cataract surgical coverage among people at 3/60 was 68.9%. Overall, 58.6% and 69.6% of the 191 eyes that had undergone cataract surgery had VA greater than or equal to 6/18 with available correction and best correction respectively.

Conclusions: The prevalence of blindness in this population in Kilimanjaro Region was low, reflecting high cataract surgical coverage from an outreach program. Even with high cataract surgical coverage, cataract remains the leading cause of vision loss and an emphasis on quality is needed.     

宁夏回族自治区同心县50岁及以上农村人群屈光不正患病率调查

目的 调查宁夏回族自治区同心县50岁及以上农村人群屈光不正的患病情况,并了解屈光矫正前后,盲和低视力的患病情况.方法 调查研究.采用单纯随机抽样的方法对宁夏同心县50岁及以上的农村人群进行一般情况的问卷调查和视力、眼压、验光、裂隙灯显微镜、免散瞳数字眼底照相等眼部专科检查.采用卡方检验对数据进行分析.结果 共5 493例符合纳入标准,其中5 046例接受并完成了检查,应答率为91.86％,在受检的5 046例中,屈光不正2 116例,屈光不正患病率为41.93％.根据日常生活视力(PVA)标准和最佳矫正视力(BCVA)标准,盲的患病率分别为5.35％、2.02％,差异有统计学意义(x2=78.78,P＜0.01),低视力的患病率分别为15.28％、5.77％,差异有统计学意义(x2=244.54,P＜0.01).受教育程度小学以下、小学、初中、高中及以上屈光不正患病率分别为45.94％、36.42％、25.38％、33.79％,不同教育程度患病率差异有统计学意义(x2=97.89,P＜0.01);回族和汉族患病率分别为43.33％、35.92％,差异有统计学意义(x2=17.40,P＜0.01).结论 宁夏同心县50岁及以上农村人群屈光不正患病率为41.93％,根据不同标准,盲和低视力的患病率不同,不同年龄、教育程度、民族之间患病率也不同.通过屈光矫正,低视力患病率显著降低.     

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.     

Prevalence and causes of blindness and visual impairment in Limbe urban area, South West Province, Cameroon

AIM: To conduct a rapid assessment of cataract surgical services to estimate the prevalence and causes of blindness and visual impairment in members of the population aged >/=40 years in the Limbe urban area, Cameroon. METHODS: Clusters of 50 people aged >/=40 years were sampled with probability proportionate to size. Compact segment sampling was used to select households within clusters. All eligible people had their visual acuity (VA) measured by an ophthalmic nurse. An ophthalmologist examined people with VA<6/18. RESULTS: 2215 people were examined (response rate = 92.3%). The prevalence of bilateral blindness was 1.1% (95% CI: 0.7-1.5%), 0.3% (0.1-0.6%) for severe visual impairment and 3.0% (2.0-4.0%) for visual impairment. Posterior-segment disease was the leading cause of blindness (29%), followed by cataracts (21%) and optic atrophy (21%). Cataracts were the most common cause of severe visual impairment (43%) and visual impairment (48%). Most cases of blindness (50%), severe visual impairment (57%) and visual impairment (78%) were avoidable (that is, they were caused by cataracts, refractive error, corneal scar, onchocerciasis or phthisis/no globe). The cataract surgical coverage was relatively high, although 57% of eyes operated upon had a poor outcome (presenting VA<6/60). CONCLUSIONS: Although the prevalence of blindness was relatively low, most of the cases were avoidable. The implementation of an effective eye-care programme remains a priority in the Limbe urban area.     

Prevalence and causes of visual impairment and blindness in Icelanders aged 50 years and older: the Reykjavik Eye Study

Purpose: This study aimed to study the prevalences and causes of visual impairment and blindness in an Icelandic adult population. Methods: The Reykjavik Eye Study includes a random sample of citizens of Reykjavik aged ≥ 50 years, with an equal proportion (6.4%) for each year of birth and each sex. A total of 1045 persons were examined, representing a response rate of 75.8%. All participants underwent an extensive ophthalmological examination using a standard protocol. We used World Health Organization (WHO) definitions for bilateral visual impairment (best corrected visual acuity [VA] < 6/18 or visual field of ≥ 5 ° and < 10 ° around the fixation point in the better eye) and blindness (VA < 3/60 or visual field < 5 ° in the better eye). We also used US criteria, which define bilateral visual impairment as present if VA is < 6/12 and blindness as present if VA is ≤ 6/60 (both in the better eye). The causes of visual loss were determined for all participants found to be visually impaired in one or both eyes. Results: The prevalences of bilateral visual impairment and blindness were 0.96% (95% confidence interval [CI] 0.37–1.55) and 0.57% (95% CI 0.12–1.03), respectively, using the WHO criteria, and 2.01% (95% CI 1.16–2.86) and 0.77% (95% CI 0.24–1.29), respectively, using the US criteria. The prevalence rates were 4.40% and 5.45% for unilateral visual impairment and 1.72% and 3.06% for unilateral blindness, using the WHO and US criteria, respectively. Age‐related macular degeneration (AMD) was the major cause of bilateral visual loss, whereas the most common causes of unilateral visual loss were, in this order, amblyopia, cataract and glaucoma. Conclusions: Prevalence of visual loss increases with age. The leading cause of bilateral visual impairment and blindness was AMD, accounting for more than half of all cases, and cases of geographic atrophy outnumbered those of exudative AMD by two to one.