Blindness and low vision in Cape Verde Islands: results of a national eye survey

AIMS: Prior to establishing a national prevention of blindness program a population based survey was conducted in Cape Verde Islands in1998. The objectives of the survey were to estimate the overall and age-specific prevalence of blindness and low vision, to identify the main disorders causing blindness and low vision, and to estimate the population need for basic eye care services. METHODS: A two-level cluster random sampling procedure was used, selecting 30 clusters from the nine inhabited islands and 3,803 persons of all ages were included in the sample. RESULTS: 3,374 persons were examined (coverage 88.7%). The prevalence of bilateral blindness (visual acuity in the better eye less than 3/60) was 0.8% (95% confidence interval [CI] 0.5-1.1), of bilateral low vision (6/18 to 3/60 in the better eye) 1.7% (95% CI: 1.3-2.2) and of monocular blindness 1.5% (95% CI: 1.2-2.0). The major causes of blindness were age related cataract and glaucoma (57.7% and 15.4%, respectively, of blind people recruited). The major causes of bilateral low vision were cataract, refractive errors, and macular disorders (46.2%, 26.8%, and 8.9%, respectively, of persons with low vision). Nontrachomatous corneal opacities accounted for 7.7% of bilateral and for 11.5% of monocular blindness. Vascular retinopathy was responsible for 7.7% of bilateral and for 9.6% of monocular blindness. Trachoma is not a public health problem as only 2.3% of children less than 10 years of age were suffering from active trachoma. Palpebral or limbal vernal conjunctivitis were encountered in 4.5% of persons under 25. CONCLUSION: More than half of the visual impairments are treatable by provision of cataract surgery and cataract has been indicated as a priority target in the recently designed National Blindness Program of the Cape Verde Republic. Pathologic conditions such as diabetes are emerging as serious burden for ageing populations and account for most of the retinal vascular disease.     

Blindness and Eye Disease in Cambodia

Purpose: To assess the prevalence and etiology of blindness and low vision and to assess the prevalence of common eye diseases in central Cambodia. Methods: In this cross-sectional, population-based study, 6,558 residents of Kandal Province, Cambodia were registered, and 5,803 (88.5%) were interviewed and examined. This house-to-house survey was conducted by a team consisting of a senior ophthalmologist, a Cambodian eye doctor, and eight Cambodian eyecare workers. Results: The prevalence of bilateral blindness (visual acuity <3/60) is 1.1% (95% confidence interval [CI], 0.9–1.4), and an additional 4.4% (95% CI, 3.9–5.0) have low vision (visual acuity < 6/18, ≥3/60 in the better eye). The major causes of bilateral blindness are cataract (67.4%), phthisis (6.1%), uncorrected refractive error (6.1%), corneal scar (5.3%), uncorrected aphakia (3.0%), trachoma corneal scar (3.0%), optic atrophy (3.0%), and others (6.1%). The major causes of low vision are uncorrected refractive error (49.8%) and cataract (42.7%). The prevalence of unilateral blindness is 1.2% (95% CI, 0.9–1.4), often caused by cataract, corneal scar, or phthisis. Trauma due to landmine explosions and war-related injuries was frequently the underlying etiology in subjects with phthisis, corneal scarring, or other pathology.Conclusions: The prevalence of blindness and low vision in Cambodia is relatively high compared to other developing countries. Most of the causes of blindness and low vision are treatable or preventable. Landmines and other war-related injuries are an important cause of ocular injury. These results will assist in developing a national plan for the prevention of blindness in Cambodia.     

Causes of low vision and blindness in rural Indonesia

AIM: To determine the prevalence rates and major contributing causes of low vision and blindness in adults in a rural setting in Indonesia METHODS: A population based prevalence survey of adults 21 years or older (n=989) was conducted in five rural villages and one provincial town in Sumatra, Indonesia. One stage household cluster sampling procedure was employed where 100 households were randomly selected from each village or town. Bilateral low vision was defined as habitual VA (measured using tumbling "E" logMAR charts) in the better eye worse than 6/18 and 3/60 or better, based on the WHO criteria. Bilateral blindness was defined as habitual VA worse than 3/60 in the better eye. The anterior segment and lens of subjects with low vision or blindness (both unilateral and bilateral) (n=66) were examined using a portable slit lamp and fundus examination was performed using indirect ophthalmoscopy. RESULTS: The overall age adjusted (adjusted to the 1990 Indonesia census population) prevalence rate of bilateral low vision was 5.8% (95% confidence interval (CI) 4.2 to 7.4) and bilateral blindness was 2.2% (95% CI 1.1 to 3.2). The rates of low vision and blindness increased with age. The major contributing causes for bilateral low vision were cataract (61.3%), uncorrected refractive error (12.9%), and amblyopia (12.9%), and the major cause of bilateral blindness was cataract (62.5%). The major causes of unilateral low vision were cataract (48.0%) and uncorrected refractive error (12.0%), and major causes of unilateral blindness were amblyopia (50.0%) and trauma (50.0%). CONCLUSIONS: The rates of habitual low vision and blindness in provincial Sumatra, Indonesia, are similar to other developing rural countries in Asia. Blindness is largely preventable, as the major contributing causes (cataract and uncorrected refractive error) are amenable to treatment.     

Cataract blindness in Paraguay – results of a national survey

PURPOSE To estimate the burden of visual loss and blindness due to cataract in people aged 50 years and over in Paraguay. METHODS Forty clusters of 60 persons each who were 50 years and older (2400 eligible persons) were selected by systematic random sampling from the entire population of Paraguay.A total of 2136 persons were examined (89% coverage). RESULTS For the population 50 years and over, the age- and gender- adjusted prevalence of bilateral blindness (VA &lt; 3/60 with available correction) was 3.14% (95% CI: 2.2–4.4). The adjusted prevalence of bilateral cataract blindness (VA &lt; 3/60) was 2.01% (95% CI: 1.3–3.0), making cataract the major cause of bilateral blindness in this age group (64%). The adjusted prevalence of bilateral severe visual impairment (VA &lt; 6/60 with available correction) was 5.17% (95% CI: 3.9–6.7) and the adjusted prevalence of severe visual impairment due to bilateral cataract (VA &lt; 6/60) was 3.09% (95% CI: 2.2–4.3). The cataract surgical coverage (persons) was 44% for bilaterally blind persons with VA &lt; 3/60; 36% for persons with bilateral VA &lt; 6/60; and 28% for any eye with VA &lt; 6/60 due to cataract. With IOL implantation, 77% of the operated eyes could see 6/18, against 46% of the non-IOLs (p &lt; 0.005), a significant better outcome. CONCLUSIONS There is a need to increase the cataract surgical coverage in Paraguay. The number of eye surgeons is adequate but the accessibility of cataract surgical services in rural areas and the affordability of surgery to large sections of society are major constraints.     

Prevalence and Causes of Blindness,Low Vision and Status of Cataract in 50 Years and Older Citizen of Qatar—A Community Based Survey

Background: Rapid Assessment for the Avoidable Blindness (RAAB) was conducted in Qatar during 2009. We present the prevalence and determinants of visual disabilities and status of cataract among citizens aged 50 years and older.

Methods: Residents of randomly selected houses and clusters participated in the survey. Opticians noted the presenting and the best corrected vision of participants from 49 clusters. Ophthalmologists examined participants with additional instruments like bio-microscope, digital camera, auto-perimeter and auto-refractor in a mobile van. World Health Organization recommended principal cause of blindness (Visual acuity [VA]?<?3/60 in better eye), Severe visual impairment (SVI) (<6/60), low vision (VA?<?6/18) and unilateral blindness (VA?<?3/60) were designated. Persons with VA?<?6/18 and cataract were interviewed to calculate coverage and barriers for cataract surgeries. Age sex adjusted prevalence of visual disabilities and their 95% Confidence Intervals (CI) were estimated.

Results: We examined 2,433 (97.3%) participants. The age sex adjusted prevalence of bilateral blindness was 1.28% [95% CI 1.22–1.35], SVI (1.67%), low vision (3.66%) and unilateral blindness (3.61%) in 50 years and older population. Female and older age groups were significant risk factors of visual disabilities. Cataract and glaucoma were the main causes of visual disabilities. The coverage of cataract services was 68.2%. Believing that cataract as an aging process (25) and adequate vision in the fellow eye (15) were the reasons for delay in surgery.

Conclusions: To reduce avoidable blindness, un-operated cataract should be addressed. Primary and secondary eye care systems should be strengthened to improve the care of blinding eye diseases in Qatar.     

Prevalence and Causes of Blindness and Low Vision Revisited after 5 years of Eye Care in Timor-Leste

Purpose: To estimate the 2010 prevalence and causes of blindness and low vision among Timor-Leste adults aged ≥40 years, and compare these to the results of a survey conducted 5 years previously.

Method: A population-based cross-sectional survey used multistage cluster random sampling proportionate to size to identify 50 clusters of 45 people each. Cause of vision loss was determined for each eye with presenting visual acuity worse than 6/18.

Results: A participation rate of 89.5% (n?=?2014) was achieved. The gender-age-domicile adjusted prevalence was 7.7% (95% confidence interval [CI] 6.5, 8.8) for 6/60, and 3.6% (95% CI 2.7, 4.4) for 3/60 blindness (better eye presenting vision worse than 6/60 and 3/60, respectively) among Timorese aged ≥40 years. Cataract caused most blindness (69.3% at 6/60). The population prevalence of low vision (better eye presenting vision of 6/60 or better, but worse than 6/18) was 13.6% (95%CI 12.1, 15.1), most caused by uncorrected refractive error (57.4%) or cataract (39.5%). The prevalence and causes of blindness were unchanged compared with 5 years earlier, but low vision was less common.

Conclusion: Unusually for a developing country, Timor-Leste has initiated a cycle of evidence-based eye care in which, although with limitations, population data are periodically available for monitoring and planning.     

Prevalence of blindness and low vision in Malaysian population: results from the National Eye Survey 1996

BACKGROUND: A national eye survey was conducted in 1996 to determine the prevalence of blindness and low vision and their major causes among the Malaysian population of all ages. METHODS: A stratified two stage cluster sampling design was used to randomly select primary and secondary sampling units. Interviews, visual acuity tests, and eye examinations on all individuals in the sampled households were performed. Estimates were weighted by factors adjusting for selection probability, non-response, and sampling coverage. RESULTS: The overall response rate was 69% (that is, living quarters response rate was 72.8% and household response rate was 95.1%). The age adjusted prevalence of bilateral blindness and low vision was 0.29% (95% CI 0.19 to 0.39%), and 2.44% (95% CI 2.18 to 2.69%) respectively. Females had a higher age adjusted prevalence of low vision compared to males. There was no significant difference in the prevalence of bilateral low vision and blindness among the four ethnic groups, and urban and rural residents. Cataract was the leading cause of blindness (39%) followed by retinal diseases (24%). Uncorrected refractive errors (48%) and cataract (36%) were the major causes of low vision. CONCLUSION: Malaysia has blindness and visual impairment rates that are comparable with other countries in the South East Asia region. However, cataract and uncorrected refractive errors, though readily treatable, are still the leading causes of blindness, suggesting the need for an evaluation on accessibility and availability of eye care services and barriers to eye care utilisation in the country.     

Blindness and eye disease in Cambodia

PURPOSE: To assess the prevalence and etiology of blindness and low vision and to assess the prevalence of common eye diseases in central Cambodia. METHODS: In this cross-sectional, population-based study, 6,558 residents of Kandal Province, Cambodia were registered, and 5,803 (88.5%) were interviewed and examined. This house-to-house survey was conducted by a team consisting of a senior ophthalmologist, a Cambodian eye doctor, and eight Cambodian eyecare workers. RESULTS: The prevalence of bilateral blindness (visual acuity <3/60) is 1.1% (95% confidence interval [CI], 0.9-1.4), and an additional 4.4% (95% CI, 3.9-5.0) have low vision (visual acuity < 6/18, > or =3/60 in the better eye). The major causes of bilateral blindness are cataract (67.4%), phthisis (6.1%), uncorrected refractive error (6.1%), corneal scar (5.3%), uncorrected aphakia (3.0%), trachoma corneal scar (3.0%), optic atrophy (3.0%), and others (6.1%). The major causes of low vision are uncorrected refractive error (49.8%) and cataract (42.7%). The prevalence of unilateral blindness is 1.2% (95% CI, 0.9-1.4), often caused by cataract, corneal scar, or phthisis. Trauma due to landmine explosions and war-related injuries was frequently the underlying etiology in subjects with phthisis, corneal scarring, or other pathology.CONCLUSIONS: The prevalence of blindness and low vision in Cambodia is relatively high compared to other developing countries. Most of the causes of blindness and low vision are treatable or preventable. Landmines and other war-related injuries are an important cause of ocular injury. These results will assist in developing a national plan for the prevention of blindness in Cambodia.     

A population-based eye survey of older adults in a rural district of Rajasthan: I. Central vision impairment, blindness, and cataract surgery

PURPOSE: To assess the prevalence of central vision blindness and cataract surgery in older adults in rural northwest India. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: A total of 4284 examined persons 50 years of age or older. METHODS: A random selection of village-based clusters was used to identify a population sample in the predominantly rural Bharatpur district of Rajasthan. Eligible subjects in the 25 selected clusters were enumerated through a door-to-door household survey and invited to village sites for visual acuity testing and eye examination early in 1999. The principal cause of reduced central vision was identified for eyes that had visual acuity worse than 6/18. Independent replicate testing for quality assurance monitoring took place in participants with reduced vision and in a sample of those with normal vision in five of the study clusters. MAIN OUTCOME MEASURES: Presenting and best-corrected visual acuity and lens status. RESULTS: A total of 4728 eligible persons in 2821 households were enumerated, and 4284 (90.6%) were examined. The prevalence of presenting and best-corrected visual acuity worse than 6/60 in both eyes was 11.9% (95% confidence interval: 10.0%-13.9%) and 6.1% (95% CI: 4.7%-7.4%), respectively. Presenting blindness was associated with increasing age, female gender, lack of schooling, and rural residence. Cataract was the principal cause of blindness in one or both eyes in 67.5% of blind persons, with uncorrected aphakia and other refractive error affecting 18.4% in at least one eye. The prevalence of cataract surgery was 12.8% (95% CI: 11.6%-14.0%), with an estimated 65.7% of the cataract blind operated on; low surgical coverage was associated with lack of schooling. CONCLUSIONS: Blindness, particularly blindness because of cataract, continues to be a significant problem among the elderly living in remote areas of rural northwest India. Increased attention should be given to reaching women and the illiterate.     

Causes of blindness, low vision, and questionnaire-assessed poor visual function in Singaporean Chinese adults: The Tanjong Pagar Survey

OBJECTIVE: To determine the prevalence rates and causes of low vision, blindness, and patient-assessed deficient visual function among Singaporean Chinese adults. DESIGN: Population-based cross-sectional survey. PARTICIPANTS: Singaporean Chinese adults 40 to 79 years old (n = 1152). METHODS: From an initial sampling frame of 40- to 79-year-old Chinese in the Tanjong Pagar district in Singapore, 2000 subjects were selected using a disproportionate, stratified, clustered, random-sampling method. Of 1717 eligible subjects, 1232 were examined (participation rate = 71.8%), and 80 adults who did not have visual acuity (VA) data were excluded from the analysis. MAIN OUTCOME MEASURES: Bilateral low vision was defined as best-corrected VA (BCVA) worse than 6/18 and 3/60 or better, and bilateral blindness as BCVA worse than 3/60 in the better eye or constriction of the visual field to within 10 degrees of fixation, in accordance with the World Health Organization criteria. Patient-assessed visual function was measured using a modified VF-14 questionnaire. RESULTS: The age- and gender-adjusted prevalence rates were 1.1% (95% confidence interval [CI], 0.6-1.8) for bilateral low vision and 0.5% (95% CI, 0.2-1.1) for bilateral blindness, and the mean visual function score was 98.6. The rates of bilateral low vision and blindness increased with age, whereas visual function scores decreased with age, even after adjusting for gender and education. Cataract accounted for 58.8% of bilateral low vision, 20.0% of bilateral blindness, and 52.0% of poor visual function (score<90). Glaucoma contributed to 60.0% of bilateral blindness. CONCLUSION: The age- and gender-adjusted rates of low vision and blindness were 1.1% and 0.5%, respectively. Glaucoma is a leading cause of blindness in Singaporean Chinese adults, in addition to well-recognized causes in the rest of Asia such as cataract.     

Use of Cataract Services in Eastern Africa—A Study from Tanzania

Purpose: To establish the proportion of patients who are blind or have low vision prior to undergoing cataract surgery at tertiary referral centers in Tanzania. To assess which patient groups presenting for cataract surgery are more likely to be blind or visually impaired. Methods: Using pre-existing computerized audit systems we gathered data on pre-operative visual status, age, gender and presentation mode (walk-in or outreach) for 3765 patients undergoing 4258 cataract operations at 2 hospitals in Tanzania. Visual status was defined based on vision in the better eye. Results: 32% of operations were performed on blind patients, 37% on patients with low vision and 31% on normally sighted patients. Predictors of blindness at presentation were: female sex (OR 1.15; 95% CI 1.00–1.32); referral from a rural outreach program (OR 1.75; 95% CI 1.51–2.02) and older age (OR 1.02; 95% CI 1.01–1.02). Conclusions: It is not only the blind who present to cataract services in Tanzania. The demand for surgery amongst patients who or are normally sighted represents a positive move towards prevention, and not only cure of cataract blindness in Tanzania. However, it also highlights the need to target those left blind from cataract in order to deliver services to those most in need. Cataract programs targeting patients in rural areas and older patients are likely to increase the number of blind patients benefiting from cataract services.     

Prevalence and causes of blindness and low vision in Timor-Leste

AIM: To estimate the prevalence and causes of blindness and low vision in people aged > or = 40 years in Timor-Leste. METHOD: A population-based cross-sectional survey using multistage cluster random sampling to identify 50 clusters of 30 people. A cause of vision loss was determined for each eye presenting with visual acuity worse than 6/18. RESULTS: Of 1470 people enumerated, 1414 (96.2%) were examined. The age, gender and domicile-adjusted prevalence of functional blindness (presenting vision worse than 6/60 in the better eye) was 7.4% (95% CI 6.1 to 8.8), and for blindness at 3/60 was 4.1% (95% CI 3.1 to 5.1). The adjusted prevalence for low vision (better eye presenting vision of 6/60 or better, but worse than 6/18) was 17.7% (95% CI 15.7 to 19.7). Gender was not a risk factor for blindness or low vision, but increasing age, illiteracy, subsistence farming, unemployment and rural domicile were risk factors for both. Cataract was the commonest cause of blindness (72.9%) and an important cause of low vision (17.8%). Uncorrected refractive error caused 81.3% of low vision. CONCLUSION: Strategies that make good-quality cataract and refractive error services available, affordable and accessible, especially in rural areas, will have the greatest impact on vision impairment.     

Low vision and blindness in adults in Gurage Zone,central Ethiopia

AIM: To determine the magnitude and causes of low vision and blindness in the Gurage zone, central Ethiopia. METHODS: A cross sectional study using a multistage cluster sampling technique was used to identify the study subjects. Visual acuity was recorded for all adults 40 years and older. Subjects who had a visual acuity of <6/18 were examined by an ophthalmologist to determine the cause of low vision or blindness. RESULTS: From the enumerated population, 2693 (90.8%) were examined. The prevalence of blindness (<3/60 better eye presenting vision) was 7.9% (95% CI 6.9 to 8.9) and of low vision (6/24-3/60 better eye presenting vision) was 12.1% (95% CI 10.9 to 13.3). Monocular blindness was recorded in 16.3% of the population. Blindness and low vision increased with age. The odds of low vision and blindness in women were 1.8 times that of the men. The leading causes of blindness were cataract (46.1%), trachoma (22.9%), and glaucoma (7.6%). While the prevalence of vision reducing cataract increased with age, the prevalence of trachoma related vision loss did not increase with age, suggesting that trichiasis related vision loss in this population might not be cumulative. CONCLUSION: The magnitude of low vision and blindness is high in this zone and requires urgent intervention, particularly for women. Further investigation of the pattern of vision loss, particularly as a result of trachomatous trichiasis, is warranted.     

云南省个旧市盲人调查和治疗

目的     

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.     

拉萨市林周县40岁及以上人群中盲的患病率调查

目的：调查拉萨市林周县40岁及以上人群中的盲患病率。方法：2000年4－6月采用整群抽样方法,抽取林周县44个自然村40岁及以上人群3153人进行视力及眼部检查,根据小孔视力和世界卫生组织视力损伤标准（标准A）及日常生活视力和视力损伤标准(标准B）计算盲的患病率。结果：在应受检的3153人中,实际接受检查人数为3071人,受检率为97．4％。（1）以标准A计算盲的患病率：双眼盲的患病率为2．3％（95％可信区间：1．8－2．8）;盲的患病率随年龄增长而增加（P＜0．001）;男性高于女性,差异无显著意义（P＞0．05）,调整年龄后差异有显著意义（P＜0．05）;文盲中盲的患病率高于非文盲者,差异有显著意义（P＜0．001）,调整年龄后差异无显著意义（P＞0．05）;文盲中盲的患病率高于非文盲者,差异有显著意义（P＜0．001）,调整年龄后差异无显著意义（P＞0．05）。（2）以标准B计算盲的患病率：盲的患病率为3．2％（95％可信区间：2．6－3．8）;盲的患病率亦随年龄增长而增加（P＜0．001）;男与女盲的患病率优势比值为1．2,差异无显著意义（P＞0．05）,调整年龄后差异无显著意义（P＜0．001）;男与女盲的患病率优势比值为1．2,差异无显著意义（P＞0．05）,调整年龄后差异无显著意义（P＞0．05）;文盲中盲的患病率高于非文盲者,差异有显著意义（P＜0．001）,调整年龄后差异无显著性（P＞0．05）。结论：高原地区盲的患病率高于内地。白内障是盲的主要原因。     

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.     

Incidence of blindness and low vision in a sample population: the Priverno Eye Study,Italy

PURPOSE: To study the incidence of blindness and low vision over a 7-year period. DESIGN: Population-based cohort study. PARTICIPANTS: The survivors of the original cohort of 860 persons from Priverno, Italy, aged 45 to 69 years, were reexamined. Of the 760 eligible survivors, 619 (81.4%) had a 7-year follow-up visit. METHODS: Baseline and follow-up examinations included the collection of anamnestic and ophthalmologic data by the same observers using the same methods and classification criteria to minimize sources of variability. MAIN OUTCOME MEASURES: Best-corrected visual acuity (VA) measured at 4 m by standardized logarithmic chart was expressed as the logarithm of the minimum angle of resolution (logMAR). World Health Organization definitions of blindness and low vision were adopted (respectively, VA > 1.3 logMar and VA > 0.6 to 1.3 logMar in the better eye or in either eye). Participants at risk for visual impairment were those without blindness or low vision in one or both eyes at baseline; participants at risk for one-eye visual impairment were those without blindness or low vision in both eyes at baseline. RESULTS: A total of 33 participants were defined as incident cases of visual impairment. The overall incidence figures for blindness, low vision, one-eye blindness, and one-eye low vision were respectively 0.2% (95% confidence interval [CI], 0.0-0.9), 1.3% (95% CI, 0.7-2.6), 1.2% (95% CI, 0.6-2.4), and 2.9% (95% CI, 1.8-4.6). CONCLUSIONS: This study provides population-based estimates of the incidence of visual impairment in an adult, free-living European population. With respect to the younger participants, older subjects at baseline were at higher risk for incident visual impairment, the main causes of which were cataract, myopia, and diabetic retinopathy. The incidence of visual impairment in the subgroup aged 55 to 64 years at baseline was significantly higher than that found in Beaver Dam 5-year study and similar to that found in Beaver Dam 10-year Study, when the same definitions were adopted. This difference may be partially explained by social and cultural habits of the female samples, but many other factors may play a role.     

Prevalence and causes of blindness and low vision in a rural setting in Pakistan

PURPOSE: To determine the prevalence and causes of blindness and visual impairment in people 40 years of age and older in Budni, Peshawar, Pakistan. METHODS: A population-based cross-sectional study was carried out involving 1,106 men and women 40 years of age and older in a rural area in Pakistan's North West Frontier Province (NWFP). All subjects with a presenting visual acuity < 6/18 in either eye were referred to a centralized clinic for a standardized eye examination that included refraction and dilated fundal examination. The main outcome was blindness (presenting visual acuity < 3/60 in the better eye) and low vision (presenting VA < 6/18-3/60 in the better eye). RESULTS: Of 1,106 people examined, 21 (1.9%; 95% CI: 1.1-2.7%) were blind, while another 27 (2.4%) and 62 (5.5%) subjects had severe visual impairment (< 6/60-3/60) and visual impairment (< 6/18-6/60), respectively. Women, as compared to men, had a higher prevalence of visual impairment and severe visual impairment; but they had a lower prevalence of blindness (1.6 vs. 2.2%); however, the difference was not statistically significant (0.6%; 95% CI: -0.9-2.1%). Similarly farmers had the highest prevalence of blindness. The leading cause of blindness and low vision was cataract, which accounted for 14 of 21 (66.6%) cases of blindness and 49 of 89 (55.5%) cases of low vision. The second leading cause of blindness was uncorrected aphakia. CONCLUSION: Much of the blindness was due to unoperated cataract and uncorrected aphakia. Thus, there is an urgent need to develop ways in which cataract surgical output could be increased, and glasses provided to those who need them.