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Purpose To assess the influence of distance and near visual impairment on self-reported near visual functioning (VF) among adults in a multi-country study. Design Population-based cross-sectional study. Participants Participants aged ≥35 years were randomly selected with cluster sampling at seven sites: rural sites in Nepal (Kaski) and India (Madurai), a semi-rural site in China (Shunyi), semi-urban sites in South Africa (Durban) and Niger (Dosso), and urban sites in the United States (Los Angeles) and China (Guangzhou). Methods Binocular presenting distance and near visual acuity (VA) were measured with a LogMAR tumbling E chart at 4 meters and 40 cm, respectively. A 12-item near VF questionnaire interview was administered by trained local interviewers, with responses scored from 100 to 0 as visual “disability” increased. Multiple linear regression was used to investigate the association of age, gender, education and VA with overall eyesight, difficulty with activities and social functioning subscale scores. Main Outcome Measures VF subscale scores. Results The study sample consisted of 6,851 questionnaire respondents. The VF subscale scores decreased significantly with worse distance and near VA, and even mildly impaired VA could result in reduced VF at all sites. In multiple linear regression modeling, lower VF subscale scores were associated with older age in four sites, female gender in three sites, and greater education in two sites. The influence of near VA was greater than that of distance VA in three sites, and in one site distance VA was more influential than near VA. With study site included in the regression modeling, lower scores for the overall eyesight subscale (compared to the Shunyi reference site) were found in Guangzhou, Kaski and Durban; lower difficulty in activities scores were found in Kaski and Durban, but better scores in Guangzhou and Madurai; social functioning scores were lower in Kaski, Durban and Dosso. Conclusions Along the entire VA spectrum, lower levels of distance and near VA led to significant reductions in VF subscale scores, with wide variation both within and between study sites. The impact of near vision on VF should receive greater emphasis with further investigation in various socio-economic and cultural settings.

PurposeTo estimate the nationwide prevalence of visual impairment and associated refractive error in school children in Bhutan.MethodsThe sample of this prospective cross-sectional national survey comprised of randomly selected classes in levels IV-IX (age 10 to 15 years) from schools throughout Bhutan. The examination included measurement of visual acuity (VA), evaluation of ocular motility, refraction under cycloplegia, examination of the external eye, media and fundus. The principal cause of impairment was determined for eyes with uncorrected VA ≤6/12. The main outcome measures were distance VA and cycloplegic refractive error.ResultsWith a sampling frame of 1967 class-based clusters from 190 schools, 160 classes in 103 schools were randomly selected; 4985 (98.5%) of 5060 enumerated children were examined. The prevalence of uncorrected, presenting, and best-corrected visual impairment (VA≤6/12) in the better eye was 14.5%, 12.8%, and 0.34%, respectively. Refractive error was the principal cause (94.2%) of impaired vision and 88% of children who could achieve VA ≥6/9 with best correction were without necessary spectacles. The prevalence of myopia (≤ -0.5 D) was 6.64% and was associated with female gender (P = 0.004), urban schooling (P = 0.002), and greater parental education (PConclusionsReduced vision because of uncorrected refractive error is a public health problem among school-age children in Bhutan. Effective school eye health strategies are needed to eliminate this easily treatable cause of visual impairment.

PurposeTo assess the potential of ready-made (spherical) spectacles (RMS) in meeting the need for refractive correction in visually impaired children in China.MethodsEligible children aged 5–17 years were identified from the three study sites in China. Distance visual acuity was measured with a retroilluminated logarithm of the minimum angle of resolution chart with tumbling E optotypes. Cycloplegic autorefraction was performed on all children using a handheld autorefractor. If uncorrected visual acuity (UCVA) was ≤20/40 in either eye, best corrected visual acuity was measured with subjective refractive error.Results A total of 13 702 children were enumerated from the three studies, with 12 334 (90.0%) having both reliable visual acuity measurements and successful cycloplegia. Among the 12 334 study children, the prevalence of UCVA ≤20/40 in the better seeing eye was 16.4% (95% CI 15.0% to 17.8%), with 91.1% (1843) of these improving by ≥3 lines of visual acuity with refractive correction. Prevalence was 12.7% (95% CI 11.5% to 13.9%) for UCVA <20/50 with 97.4% (1521) improving by ≥3 lines, and 9.38% (95% CI 8.39% to 19.4%) for UCVA ≤20/63 with 98.4% (1138) improving by ≥3 lines. Depending on the severity of visual impairment, 62.8%–64.0% of children could be accommodated with RMS if not correcting for astigmatism of ≤0.75 dioptres and anisometropia of ≤0.50 spherical equivalent dioptres. Approximately 87% of children could be accommodated with RMS if astigmatism and anisometropia limits were increased to ≤1.25 and ≤1.50 dioptres, respectively.ConclusionsRMS could substantially alleviate visual morbidity in two-thirds or more of visually impaired schoolchildren in China. This cost-effective approach to refractive correction might also be useful in low/middle-income countries with poor access to optometric services.

To estimate the prevalence of vision impairment and blindness in 2014 among older adults in rural China with comparisons with the 2006 Nine-Province Survey.Population-based, cross-sectional study.Geographical cluster sampling was used in randomly selecting residents from a rural county or semi-rural district within 9 provinces: Beijing, Jiangsu, Guangdong, Heilongjiang, Jiangxi, Hebei, Ningxia, Chongqing, and Yunnan. Persons 50 years of age or older were enumerated through household visits and invited to examination sites for visual acuity testing and examination. Vision impairment and blindness in 2014 was compared with data from the 2006 survey.Among 51 310 examined persons, the prevalence of presenting vision impairment (20/63 to ≥20/400) in the better-seeing eye ranged from 6.05% to 15.3% across the 9 study sites, with presenting blindness (20/400) ranging from 0.66% to 5.35%. With best-corrected visual acuity, the prevalence of vision impairment ranged from 1.96% to 8.74%, and blindness from 0.47% to 5.01%. Vision impairment was associated with older age, female sex, and little or no education. The overall prevalence of presenting vision impairment and blindness decreased during the 2006-2014 interval by 6.31% and 29.0%, respectively; and by 16.1% and 38.0%, respectively, after standardization of 2006 prevalence rates to the 2014 population.Substantial progress has been made in the reduction of vision impairment in rural China. Nevertheless, vision impairment remains an important public health problem with substantial geographic disparities and with older age, female sex, and illiteracy as risk factors.

Purpose To investigate the progression of near vision loss and the cumulative incidence of near vision impairment (NVI) 6 years after initial examination of an urban Chinese cohort. Design Population-based, prospective cohort study. Participants People aged ≥35 years examined at baseline in the Yuexiu District of Guangzhou, China. Methods Participants examined at baseline were invited for 2-year and 6-year follow-up examinations in 2010 and 2014, respectively. Examinations included noncycloplegic autorefraction and binocular near visual acuity (NVA) with and without current near correction measured at 40 cm using a LogMAR ETDRS near vision tumbling E chart. Those with uncorrected binocular NVA (UCNVA) ≤20/40 underwent subjective refraction to obtain best-corrected binocular NVA (BCNVA). Main Outcome Measures Change in UCNVA between baseline and 2014 follow-up examinations and the 6-year cumulative incidence of vision impairment based on 3 definitions: NVA ≤20/40, ≤20/50, and ≤20/63. Results Among the 1817 baseline participants, 1595 (87.8%) were reexamined in 2010 and 1427 (78.5%) in 2014. Mean vision loss between baseline and the 2014 follow-up was 1.54 (±1.74) lines of UCNVA. Vision loss was associated with age 80 years or older, less education, and better baseline UCNVA. The 6-year cumulative incidence of uncorrected binocular NVI (UCNVI) across the 3 vision impairment definitions was 55.2% (95% confidence interval [CI], 46.1%–64.3%), 51.3% (95% CI, 44.0%–58.7%), and 42.4% (95% CI, 35.5%–49.3%), respectively. With best-corrected binocular NVI (BCNVI), incidence was 6.89% (95% CI, 4.28%–9.50%), 5.17% (95% CI, 2.89%–7.44%), and 2.62% (95% CI, 1.11%–4.12%), respectively. A higher incidence of UCNVI was associated with worse baseline UCNVA for all 3 impairment definitions. Similarly, incidence of BCNVI was associated with worse baseline BCNVA, but also with older age and education at the primary level or less. Gender was not significant for either UCNVI or BCNVI. Conclusions Approximately half of those aged 35 years or older develop UCNVI in 6 years, the overwhelming majority of whom can be corrected with spectacles. Cost-effective strategies to provide spectacles to this at-risk population remains an issue requiring further study.

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 acuityResultsIn Central and South Asia combined, age-standardised prevalences of blindness, MSVI and MVI in 2015 were for men and women aged 50+years, 3.72% (80% uncertainty interval (UI): 1.39–6.75) and 4.00% (80% UI: 1.41–7.39), 16.33% (80% UI: 8.55–25.47) and 17.65% (80% UI: 9.00–27.62), 11.70% (80% UI: 4.70–20.32) and 12.25% (80% UI:4.86–21.30), respectively, with a significant decrease in the study period for both gender. In South Asia in 2015, 11.76 million individuals (32.65% of the global blindness figure) were blind and 61.19 million individuals (28.3% of the global total) had MSVI. From 1990 to 2015, cataract (accounting for 36.58% of all cases with blindness in 2015) was the most common cause of blindness, followed by undercorrected refractive error (36.43%), glaucoma (5.81%), age-related macular degeneration (2.44%), corneal diseases (2.43%), diabetic retinopathy (0.16%) and trachoma (0.04%). For MSVI in South Asia 2015, most common causes were undercorrected refractive error (accounting for 66.39% of all cases with MSVI), followed by cataract (23.62%), age-related macular degeneration (1.31%) and glaucoma (1.09%).ConclusionsOne-third of the global blind resided in South Asia in 2015, although the age-standardised prevalence of blindness and MSVI decreased significantly between 1990 and 2015.

Purpose To study, for the first time, the effect of wearing ready-made glasses and glasses with power determined by self-refraction on children's quality of life. Methods This is a randomized, double-masked non-inferiority trial. Children in grades 7 and 8 (age 12–15 years) in nine Chinese secondary schools, with presenting visual acuity (VA) ≤6/12 improved with refraction to ≥6/7.5 bilaterally, refractive error ≤−1.0 D and

PURPOSE: To estimate surgical coverage of cataract-related vision impairment and blindness and visual acuity outcomes in operated eyes in rural China in 2014 with comparisons with the 2006 Nine-Province Survey. DESIGN: Population-based, cross-sectional study. METHODS: Geographical cluster sampling was used in randomly selecting residents from a rural county or semi-rural district within 9 provinces: Beijing, Jiangsu, Guangdong, Heilongjiang, Jiangxi, Hebei, Ningxia, Chongqing, and Yunnan. Persons 50 years of age or older were enumerated through household visits and invited to examination sites for visual acuity testing and ocular examination. Surgical coverage and visual acuity outcomes in 2014 were compared with data from the 2006 survey. RESULTS: Among 51 310 examined persons, surgical coverage among those presenting with cataract-related severe visual impairment or blindness (

To estimate the age-, gender-, and ethnicity-specific prevalence of amblyopia in children aged 5 to 15 years using data from the multi-country Refractive Error Study in Children (RESC).Population-based, cross-sectional study.Among 46 260 children aged 5 to 15 years who were enumerated from 8 sites in the RESC study, 39 551 had a detailed ocular examination and a reliable visual acuity (VA) measurement in 1 or both eyes. Information on ethnicity was available for 39 321 of these participants. This study focused on findings from the 39 321 children.The examination included VA measurements, evaluation of ocular alignment and refractive error under cycloplegia, and examination of the external eye, anterior segment, media, and fundus.The proportion of children aged 5 to 15 years with amblyopia in different ethnic cohorts. Amblyopia was defined as best-corrected visual acuity (BCVA) of ≤20/40 in either eye, with tropia, anisometropia (≥2 spherical equivalent diopters [D]), or hyperopia (≥+6 spherical equivalent D), after excluding children with fundus or anterior segment abnormalities.The overall prevalence of amblyopia was 0.74% (95% confidence interval, 0.64-0.83) with significant (P0.001) variation across ethnic groups: 1.43% in Hispanic, 0.93% in Chinese, 0.62% in Indian, 0.52% in Malay, 0.35% in Nepali, and 0.28% in African children. Amblyopia was not associated with age or gender. The most common cause of amblyopia was anisometropia.In this study, the prevalence of amblyopia varied with ethnicity and was highest in Hispanic children and lowest in African children. Most cases were unilateral and developed before the age of 5 years. The impact of changes of definitions on prevalence estimates is discussed.

Purpose To estimate the prevalence, potential determinants, and proportion of met need for near vision impairment (NVI) correctable with refraction approximately 2 years after initial examination of a multi-country cohort. Design Population-based, prospective cohort study. Participants People aged ≥35 years examined at baseline in semi-rural (Shunyi) and urban (Guangzhou) sites in China; rural sites in Nepal (Kaski), India (Madurai), and Niger (Dosso); a semi-urban site (Durban) in South Africa; and an urban site (Los Angeles) in the United States. Methods Near visual acuity (NVA) with and without current near correction was measured at 40 cm using a logarithm of the minimum angle of resolution near vision tumbling E chart. Participants with uncorrected binocular NVA ≤20/40 were tested with plus sphere lenses to obtain best-corrected binocular NVA. Main Outcome Measures Prevalence of total NVI (defined as uncorrected NVA ≤20/40) and NVI correctable and uncorrectable to >20/40, and current spectacle wearing among those with bilateral NVA ≤20/63 improving to >20/40 with near correction (met need). Results Among 13 671 baseline participants, 10 533 (77.2%) attended the follow-up examination. The prevalence of correctable NVI increased with age from 35 to 50–60 years and then decreased at all sites. Multiple logistic regression modeling suggested that correctable NVI was not associated with gender at any site, whereas more educated persons aged >54 years were associated with a higher prevalence of correctable NVI in Nepal and India. Although near vision spectacles were provided free at baseline, wear among those who could benefit was Conclusions Prevalence of correctable NVI is greatest among persons of working age, and rates of correction are low in many settings, suggesting that strategies targeting the workplace may be needed.

Objective To compare visual and refractive outcomes between self-refracting spectacles (Adaptive Eyecare, Ltd, Oxford, UK), noncycloplegic autorefraction, and cycloplegic subjective refraction. Design Cross-sectional study. Participants Chinese school-children aged 12 to 17 years. Methods Children with uncorrected visual acuity ≤6/12 in either eye underwent measurement of the logarithm of the minimum angle of resolution visual acuity, habitual correction, self-refraction without cycloplegia, autorefraction with and without cycloplegia, and subjective refraction with cycloplegia. Main Outcome Measures Proportion of children achieving corrected visual acuity ≥6/7.5 with each modality; difference in spherical equivalent refractive error between each of the modalities and cycloplegic subjective refractive error. Results Among 556 eligible children of consenting parents, 554 (99.6%) completed self-refraction (mean age, 13.8 years; 59.7% girls; 54.0% currently wearing glasses). The proportion of children with visual acuity ≥6/7.5 in the better eye with habitual correction, self-refraction, noncycloplegic autorefraction, and cycloplegic subjective refraction were 34.8%, 92.4%, 99.5% and 99.8%, respectively (self-refraction versus cycloplegic subjective refraction, P P P = 0.33). Spherical equivalent differed by ≥1.0 D in either direction from cycloplegic subjective refraction more frequently among right eyes for self-refraction (11.2%) than noncycloplegic autorefraction (6.0%; P = 0.002). Self-refraction power that differed by ≥1.0 D from cycloplegic subjective refractive error (11.2%) was significantly associated with presenting without spectacles ( P = 0.011) and with greater absolute power of both spherical ( P = 0.025) and cylindrical ( P = 0.022) refractive error. Conclusions Self-refraction seems to be less prone to accommodative inaccuracy than noncycloplegic autorefraction, another modality appropriate for use in areas where access to eye care providers is limited. Visual results seem to be comparable. Greater cylindrical power is associated with less accurate results; the adjustable glasses used in this study cannot correct astigmatism. Further studies of the practical applications of this modality are warranted. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.

Purpose To investigate the prevalence and visual acuity (VA) outcomes of cataract surgery in rural populations throughout China. Design Population-based, cross-sectional study. Participants Forty-five thousand seven hundred forty-seven adults 50 years of age and older. Methods Geographically defined cluster sampling was used in randomly selecting a cross-section of residents from a representative rural county within each of 9 provinces in mainland China. Participants underwent VA measurements, refraction, and a slit-lamp examination at local examination sites; those with previous cataract surgery were queried as to the year and type of surgical facility. Surgical procedure and evidence of surgery complications were noted during the examination. The principal cause of visual impairment was identified for eyes with VA of 20/40 or worse. Main Outcome Measures Cataract surgery procedure, presenting and best-corrected distance VA, and causes of visual impairment. Results Of 50 395 enumerated eligible persons, 45 747 (90.8%) were examined and tested for VA. The overall prevalence of cataract surgery was 2.09%. Surgical coverage among those with VA worse than 20/200 in both eyes because of cataract was 35.7%. Unoperated cataract was associated with older age, female gender, lack of education, and geographic area (province). Among the 1174 cataract-operated eyes, 31.1% had presenting VA of 20/32 or better, 15.4% had presenting VA of 20/40 to 20/63, 30.0% had presenting VA worse than 20/63 to 20/200, and 23.5% had presenting VA worse than 20/200. With best correction, the percentages were 57.6%, 6.2%, 18.5%, and 17.7%, respectively. Posterior capsule opacification, refractive error, and retinal disorders were the main causes in cataract-operated eyes with VA worse than 20/63. Conclusions Two thirds of those with bilateral visual impairment or blindness because of cataract remain in need of sight-restoring surgery. Posterior capsule opacification and refractive error, both readily amenable to treatment, were common in cataract-operated eyes. Sustained government efforts to provide access to affordable modern cataract surgery with a greater emphasis on postoperative follow-up and the quality of VA outcomes are needed. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

The cataract surgical rate (CSR) in Gujarat, India is reported to be above 10,000 per million population. This study was conducted to investigate the prevalence and causes of vision impairment/blindness among older adults in a high CSR area.Geographically defined cluster sampling was used in randomly selecting personsor= 50 years of age in Navsari district. Subjects in 35 study clusters were enumerated and invited for measurement of presenting and best-corrected visual acuity and an ocular examination. The principal cause was identified for eyes with presenting visual acuity20/32.A total of 5158 eligible persons were enumerated and 4738 (91.9%) examined. Prevalence of presenting visual impairment20/63 to 20/200 in the better eye was 29.3% (95% confidence interval [CI]: 27.5-31.2) and 13.5% (95% CI: 12.0-14.9) with best correction. The prevalence of presenting bilateral blindness (20/200) was 6.9% (95% CI: 5.7-8.1), and 3.1% (95% CI: 2.5-3.7) with best correction. Presenting and best-corrected blindness were both associated with older age and illiteracy; gender and rural/urban residence were not significant. Cataract in one or both eyes was the main cause of bilateral blindness (82.6%), followed by retinal disorders (8.9%). Cataract (50.3%) and refractive error (35.4%) were the main causes in eyes with vision acuity20/63 to 20/200, and refractive error (86.6%) in eyes with acuity20/32 to 20/63.Visual impairment and blindness is a significant problem among the elderly in Gujarat. Despite a reportedly high CSR, cataract remains the predominant cause of blindness.

AbstrA ct Purpose: Investigate the prevalence and vision-related outcomes of cataract surgery in an area of high cataract surgical rate. Methods: Cluster sampling was used in randomly selecting individuals ≥ 50 years of age in 2007. Participants were queried regarding year and place of previous cataract surgery. Cataract surgical procedures and evidence of surgical complications were recorded. The principal cause was identified for eyes presenting with visual acuity (VA) ≤ 20/40. Results: A total of 4,738 persons were examined and 834 (17.6%) had cataract surgery. Intra- ocular lenses (IOLs) were used in 84.1% of the 1,299 cataract-operated eyes, with more than half of these having manual small incision surgery. Surgical coverage among the cataract blind (visual acuity [VA] < 20/200) was estimated as 72.2%. Coverage was associated with older age, literacy, and urban residence; gender was not significant. Among cataract-operated eyes, 18.7% presented with VA ≥ 20/32 and 18.0% were < 20/200. With best-corrected acuity, the corresponding percentages were 55.7% and 11.0%. Presenting and best-corrected VA ≥ 20/63 were associated with young age, literacy, and IOL surgery; urban residence and surgery in non-governmental organizations (NGO)/ private facilities were also significant for presenting VA; and recent surgery was significant for best-corrected VA. Refractive error was the main cause of vision impairment/blindness in cataractoperated eyes. Conclusions: Refractive error and posterior capsule opacification, easily treatable causes of visual impairment, are common among the operated. A greater emphasis on the quality of visual acuity outcomes along with sustained efforts to provide access to affordable surgery is needed.

Purpose: Assess visual impairment in school children of upper-middle socioeconomic status in Kathmandu for comparison with rural Jhapa District. Methods: Random selection of classes from secondary private schools in Kathmandu was used to identify the study sample. Children in 130 classes at 43 schools were enumerated using school records and examined between January‐May 2006. Examinations included visual acuity testing, ocular motility evaluation, cycloplegic refraction, and examination of the external eye, anterior segment, media, and fundus. The principal cause was determined for eyes with uncorrected visual acuity ≤20/40. Results :A total of 4,501 children in grades 5‐9 were enumerated; 4282 (95.1%) were examined. The prevalence of uncorrected, presenting, and best-corrected visual impairment (≤20/40) in the better eye was 18.6%, 9.1%, and 0.86%, respectively. Refractive error was a cause in 93.3% of children with uncorrected visual impairment, amblyopia 1.8%, retinal disorders 1.3%, other causes 0.3%, and unexplained causes 4.4%. Among children correctable in at least one eye, 46.3% presented without the necessary spectacles. Visual impairment with myopia (-0.50 diopters) ranged from 10.9% in 10 year-olds to 27.3% in 15 year-olds, compared to 0.5%‐3.0% in rural Jhapa District. Myopic visual impairment was associated with grade level, female gender, parental education, parental spectacle usage, and Mongol ethnicity. Conclusions: Visual impairment with myopia among upper-middle socioeconomic school children in Kathmandu is higher than that in rural Nepal, and a public health problem because nearly half are without corrective spectacles. Effective strategies are needed to eliminate this easily treatable cause of visual impairment.

Purpose To evaluate the accuracy of noncycloplegic autorefraction in a representative sample of school-age children in China. Methods Refractive error was measured with an autorefractor, both before and after cycloplegia induced with cyclopentolate, in a population-based sample of 4973 children between the ages of 7 and 18 years. Spherical equivalent refractive error and astigmatism as represented by Jackson crossed-cylinders (J0 and J45) were the main outcome measures. Results Noncycloplegic measurements of equivalent spheres were consistently more negative or less positive than those after cycloplegia, with mean +/- SD differences of -1.23 +/- 0.97 D. The differences were particularly large for hyperopic eyes (mean difference of -2.98 +/- 1.65 D for hyperopia of at least +2.00 D) while becoming progressively smaller for emmetropic eyes, and smaller yet for myopic eyes (mean difference of -0.41 +/- 0.46 D for myopia of -2.00 D or more). Increasing age was associated with increased, but clinically insignificant, differences. Little difference was found between noncycloplegic and cycloplegic measurements of astigmatism: mean J0 and J45 differences were -0.08 +/- 0.13 D and -0.01 +/- 0.09 D, respectively. Conclusions Noncycloplegic autorefraction was found to be highly inaccurate in school-age children and, thus, not suitable for studies of refractive error or for prescription of glasses in this population.

PURPOSE: To assess the progression of refractive error and the incidence of myopia in school-age children in the Shunyi District of Beijing, China. DESIGN: A longitudinal cohort study. METHODS: A population-based sample of 4,662 children initially examined in 1998 at ages 5 to 13 years was reexamined between September and November, 2000. Refractive error was measured under cycloplegia with autorefraction. Age, sex, and baseline refractive error were evaluated as risk factors for progression. RESULTS: In 28.5 months, the average change in refractive error was −0.42 diopters (standard deviation, 0.68) in right eyes. Myopic shift of refractive error was associated with female sex, older age, and higher myopic or hyperopic refractive error at baseline. The average change in astigmatic error was essentially zero, with significant change in both directions more likely among those with higher baseline astigmatism. Findings were similar for left eyes. The cumulative incidence of myopia, defined as a spherical equivalent refractive error of −0.50 diopters or more in either eye, among initial emmetropes and hyperopes was 14.1% (95% confidence interval [CI], 11.8%–16.5%) for male and 23.5% (95% CI, 20.8%–26.1%) for female subjects. Myopia incidence increased sixfold to sevenfold between baseline age 5 and 12, before decreasing at age 13, for both male and female subjects. CONCLUSIONS: In the design of cost-effective programs for the periodic screening and treatment of uncorrected refractive error, children initially found to require refractive correction should be targeted for relatively frequent rescreening, as should girls and older children. Further study is required to better understand environmental and genetic risk factors for myopia development and progression.

To assess the prevalence of vision impairment, blindness, and cataract surgery and to evaluate visual acuity outcomes after cataract surgery in a south Indian population.Cluster sampling was used to randomly select a cross sectional sample of peopleor =50 years of age living in the Tirunelveli district of south India. Eligible subjects in 28 clusters were enumerated through a door to door household survey. Visual acuity measurements and ocular examinations were performed at a selected site within each of the clusters in early 2000. The principal cause of visual impairment was identified for eyes with presenting visual acuity6/18. Independent replicate testing for quality assurance monitoring was performed in subjects with reduced vision and in a sample of those with normal vision for six of the study clusters.A total of 5795 people in 3986 households were enumerated and 5411 (93.37%) were examined. The prevalence of presenting and best corrected visual acuityor =6/18 in both eyes was 59.4% and 75.7%, respectively. Presenting vision6/60 in both eyes (the definition of blindness in India) was found in 11.0%, and in 4.6% with best correction. Presenting blindness was associated with older age, female sex, and illiteracy. Cataract was the principal cause of blindness in at least one eye in 70.6% of blind people. The prevalence of cataract surgery was 11.8%-with an estimated 56.5% of the cataract blind already operated on. Surgical coverage was inversely associated with illiteracy and with female sex in rural areas. Within the cataract operated sample, 31.7% had presenting visual acuityor =6/18 in both eyes and 11.8% were6/60; 40% were bilaterally operated on, with 63% pseudophakic. Presenting vision was6/60 in 40.7% of aphakic eyes and in 5.1% of pseudophakic eyes; with best correction the percentages were 17.6% and 3.7%, respectively. Refractive error, including uncorrected aphakia, was the main cause of visual impairment in cataract operated eyes. Vision6/18 was associated with cataract surgery in government, as opposed to that in non-governmental/private facilities. Age, sex, literacy, and area of residence were not predictors of visual outcomes.Treatable blindness, particularly that associated with cataract and refractive error, remains a significant problem among older adults in south Indian populations, especially in females, the illiterate, and those living in rural areas. Further study is needed to better understand why a significant proportion of the cataract blind are not taking advantage of free of charge eye care services offered by the Aravind Eye Hospital and others in the district. While continuing to increase cataract surgical volume to reduce blindness, emphasis must also be placed on improving postoperative visual acuity outcomes.

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

Background: Visual acuity, visual functioning, and vision related quality of life outcomes after cataract surgery were assessed in a population based study in a suburban area of Hong Kong. Methods: A cluster sampling design was used to select apartment buildings within housing estates for enumeration. All enumerated residents 60 years of age or over were invited for an eye examination and visual acuity measurement at a site within each estate. Visual functioning (VF) and vision related quality of life (QOL) questionnaires were administered to interview subjects who had undergone cataract surgery and to unoperated people with presenting visual acuity less than 6/60 in either eye, and a sample of those with normal visual acuity. Results: 36.6% of the 310 cataract operated individuals had presenting visual acuity 6/18 or better in both eyes, and 40.0% when measured by pinhole. 4.5% were blind, with presenting visual acuity less than 6/60 in both eyes. Of operated eyes, 59.6% presented with visual acuity 6/18 or better. 11.2% of the operated eyes were blind with vision less than 6/60. Visual acuity outcomes 6/18 or better were marginally associated with surgery in private versus public hospitals. Lens status (pseudophakic versus aphakic) and surgical period (within the most recent 3 years versus before) were not significantly related to vision outcomes. Mean VF and QOL scores decreased consistently with decreasing vision status. Spearman correlation with vision status was 0.420 for VF scores and 0.313 for QOL scores. Among VF/QOL subscales, correlation was strongest for visual perception (r = 0.447) among VF subscales and weakest for self care (r = 0.171) among QOL subscales. Regression adjusted VF and QOL total scores for cataract operated individuals were slightly lower than for those of visually comparable unoperated individuals (p

To assess the clinical outcomes of cataract surgery in rural southern India.Cluster sampling was used in randomly selecting a cross-sectional sample of persons 50 years of age or older for visual acuity measurement, refraction, and ocular examination in 1999. Subjects were queried as to the date and place of surgery for each cataract-operated eye. Surgical complications were noted and the principal cause of reduced vision was identified for eyes with presenting visual acuity worse than 6/18.Within the cataract-operated sample of 682 persons, 13.8% had presenting visual acuity worse than 6/60 in both eyes, 25.2% better than or equal to 6/18 in both eyes, and 37.8% were bilaterally operated on. For aphakic eyes, 50.5% presented with visual acuity better than or equal to 6/18; 82.6% with best-correction. For pseudophakic eyes, the corresponding percentages were 78.0% and 94.5%. Over one-third of all eyes were pseudophakic, and nearly three-fourths had been operated on in non-governmental facilities. Uncorrected aphakia and other refractive error were the main causes of vision impairment. In multiple logistic regression modeling, poor presenting visual acuity in aphakic eyes was associated with illiteracy, rural residence, and surgery in government facilities; gender and time period of surgery were not predictors of vision outcomes. None of these variables were associated with best-corrected outcomes in aphakic eyes, nor with presenting and best-corrected outcomes in pseudophakic eyes.Visual acuity outcomes in pseudophakic eyes were good. More attention must be given to needless vision impairment among the cataract-operated because of inadequate aphakic correction, especially among those operated on in government facilities, the illiterate, and those living in rural villages.

To determine uptake, barriers and outcomes in the follow-up of patients referred for free-of-charge, expedited cataract surgery in the Sao Paulo Eye Study (SPES).SPES was a population-based study of urban, low-middle income residents aged ≥50 years. Presenting visual acuity (PVA), best-corrected visual acuity, refraction, and slit-lamp examination were performed in 3677 participants. For subjects with cataract as a principal cause of best-corrected visual acuity ≤20/40, surgery was offered free of charge. Two years after the baseline study, surgery uptake, barriers to surgery, and visual outcomes were analyzed.Among 210 (5.71%) participants who had a cataract surgery indication at baseline, 164 (78.1%) were successfully contacted and 55 (33.5%) reported being operated on for cataract, with 51 agreeing to be re-examined. In a multiple logistic regression model, age, sex, schooling, previous cataract surgery, and PVA at baseline were not significantly associated with surgery uptake. Co-existing health conditions (20.4%), fear of surgery (12.2%) and fear of losing eyesight (11.6%) were the most frequent barriers to cataract surgery adherence. Among the 69 eyes operated on in the interval between baseline and follow-up, PVA ≥20/63 was observed in 50 (72.6%, 95% confidence interval, CI, 62.2-82.3%), PVA20/63-20/200 in 11 (15.8%, 95% CI 8.9-22.9%) and PVA20/200 in 8 (11.6%, 95% CI 5.3-17.9%).Quality of surgery is an increasing determinant of uptake rates. Although free-of-charge and expedited cataract surgery was offered, surgical outcomes might have influenced the low uptake. Aside from cataract surgery campaigns, improvement of surgeon skills, accurate biometry, treatment of ocular comorbidities, postoperative follow-up and eye-care education are needed.

To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province, China.It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5 531 individuals aged 50 years or above in Yangxi County from September 2006 to January 2007. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated using village registers followed by door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity.Five thousands five hundreds and thirty-one individuals were enumerated and 4 589 persons were examined, the response rate was 82.97%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 2.38% (109/4 589) and 9.44% (433/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 2.68% (123/4 589) and 18.15% (833/4 589) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 1 239.34, P0.01) , female (χ(2) = 37.88, P0.01) and illiterate (trend χ(2) = 235.11, P0.01) persons. Cataract was the first leading cause of blindness and visual impairment.The prevalence of blindness and moderate and severe visual impairment is higher among older adults aged 50 years or above in Yangxi County. Cataract remains as the first leading cause of blindness and visual impairment.

Purpose To assess the outcomes of cataract surgery in rural northwest India. Design Population-based, cross-sectional study. Participants A total of 549 cataract-operated persons (723 operated eyes). Methods Cluster sampling was used in randomly selecting a cross-sectional sample of persons 50 years of age or older for visual acuity measurement, refraction, and slit-lamp and direct ophthalmoscope examination early in 1999. Those operated on for cataract were queried as to the date and place of surgery. The principal cause of reduced vision was identified for all examined eyes with presenting visual acuity worse than 6/18. Main outcome measures Presenting and best-corrected visual acuity and cause of vision loss. Results Presenting visual acuity was less than 6/60 in the better eye in 33.7% of cataract-operated persons and greater than or equal to 6/18 in both eyes in 8.2%; 31.7% were bilaterally operated on. Of cataract-operated eyes, 44.1% initially had visual acuity less than 6/60 and 31.5% greater than or equal to 6/18; with best correction, the corresponding percentages were 14.0% and 61.5%. Intracapsular cataract extraction was used in 92% of cases, and 66% had been operated on in surgery camps. Surgical complications were common and a major cause of vision impairment. In multiple logistic regression modeling, female gender and residence in a rural area were associated negatively with both presenting and best-corrected visual acuity outcomes, and surgery conducted before 1990 was associated negatively with best-corrected visual acuity. Place of surgery and subject schooling were not associated with vision outcomes. Conclusions Cataract surgery subjects in rural areas of India that are without adequately equipped facilities and skilled surgeons, and lack of availability of intraocular lenses, are not realizing the full sight-restoring potential of modern-day surgery. Emphasis on the quality of cataract surgery outcomes must be increased to keep pace with that being given to increasing surgical volume.

To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Longyao County, Hebei Province, China.It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5527 individuals aged ≥ 50 years in Longyao County. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Prevalence of blindness and moderate and severe visual impairment was calculated according to different age, gender or education. And the reasons of blindness were analyzed.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity.Five thousands five hundreds and twenty-seven individuals were enumerated and 5051 persons were examined, the response rate was 91.39%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 1.05% (53/5051) and 3.46% (175/5051) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.48% (75/5051) and 7.94% (401/5051) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 897.27, P = 0.000) , female (χ(2) = 30.32, P = 0.000), illiterate (trend χ(2) = 83.20, P = 0.000) persons. Cataract was still the first leading cause of blindness. Un-corrected refractive error also was the main cause of visual impairment.The prevalence of blindness and moderate and severe visual impairment is relatively lower among China Nine Province Survey. The first leading cause of blindness and visual impairment is still cataract.

To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yongchuan of Chongqing City, China.It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5663 individuals aged ≥ 50 years in Yongchuan District. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Prevalence of blindness and moderate and severe visual impairment was calculated according to different age, gender or education. And the reasons of blindness were analyzed.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity.Five thousands six hundreds and sixty-three individuals were enumerated and 5390 persons were examined, the response rate was 95.18%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 2.12% (114/5390) and 5.40% (291/5390) respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 2.49% (134/5390) and 10.71% (577/5390) respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 951.32, P = 0.000) , female (χ(2) = 33.35, P = 0.000) and illiterate (trend χ(2) equals; 141.32, P = 0.000) persons. Cataract was still the first leading cause of blindness and visual impairment.Un-corrected refractive error also was the main cause of visual impairment.The prevalence of blindness and moderate and severe visual impairment is relatively higher among older adults aged 50 years or above in Yongchuan District. The first leading cause of blindness and visual impairment is still cataract.

To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Luxi County of Yunnan Province, China.It was a population-based cross-section study. Geographically defined cluster sampling was used in randomly selecting 5575 individuals aged ≥ 50 years in Luxi County. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits.Eligible individuals were invited to receive visual acuity measurement and eye examination. Prevalence of blindness and moderate and severe visual impairment was calculated according to different age, gender or education. And the reasons of blindness were analyzed.Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity.Five thousands five hundreds and seventy-five individuals were enumerated and 5151 persons were examined, the response rate was 92.39%. Based on the criteria of World Health Organization visual impairment classification in 1973, the prevalence of blindness and moderate and severe visual impairment defined as best corrected visual acuity was 4.95% (255/5151) and 9.51% (490/5151) , respectively. The prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 5.40% (278/5151) and 15.84% (816/5151) , respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (χ(2) = 1349.21, P = 0.000) , illiterate (χ(2) = 203.55, P = 0.000) persons. Cataract was still the first leading cause of blindness and visual impairment.The prevalence of blindness and moderate and severe visual impairment is highest in China Nine-Province Survey among older adults aged ≥ 50 years in Luxi County. The first leading cause of blindness and visual impairment is still cataract.

PURPOSE: To assess the prevalence of refractive errors and vision impairment in school-age children in a suburban area (La Florida) of Santiago, Chile. METHODS: Random selection of geographically defined clusters was used to identify a representative sample of children 5 to 15 years of age. Children in the 26 selected clusters were enumerated through a door-to-door survey and invited to report to a community health clinic for examination. Visual acuity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, ocular motility evaluation, and examination of the external eye, anterior segment, media, and fundus were done from April through August 1998. Independent replicate examinations of all children with reduced vision and a sample of those with normal vision were done for quality assurance monitoring in six clusters. RESULTS: A total of 6,998 children from 3,830 households were enumerated, and 5,303 children (75.8%) were examined. The prevalence of uncorrected, presenting, and best visual acuity 0.50 (20/40) or worse in at least one eye was 15.8%, 14.7%, and 7.4%, respectively; 3.3% had best visual acuity 0.50 or worse in both eyes. Refractive error was the cause in 56.3% of the 1,285 eyes with reduced vision, amblyopia in 6.5%, other causes in 4.3%, with unexplained causes in the remaining 32.9%. Myopia −0.50 diopter or less in either eye was present in 3.4% of 5-year-old children, increasing to 19.4% in males and 14.7% in females by age 15. Over this same age range, hyperopia 2.00 diopters or greater decreased from 22.7% to 7.1% in males and from 26.3% to 8.9% in females. Females had a significantly higher risk of hyperopia than males. CONCLUSIONS: Refractive error, associated primarily with myopia, is a major cause of reduced vision in school-age children in La Florida. More than 7% of children could benefit from the provision of proper spectacles. Efforts are needed to make existing programs that provide free spectacles for school children more effective. Further studies are needed to determine whether the upward trend in myopia continues far beyond 15 years of age.

PURPOSE: To assess the prevalence of refractive error and vision impairment in school age children in the terai area of the Mechi zone in Eastern Nepal. METHODS: Random selection of village-based clusters was used to identify a sample of children 5 to 15 years of age. Children in the 25 selected clusters were enumerated through a door-to-door household survey and invited to village sites for examination. Visual acuity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, ocular motility evaluation, and anterior segment, media, and fundus examinations were done from May 1998 through July 1998. Independent replicate examinations for quality assurance monitoring took place in all children with reduced vision and in a sample of those with normal vision in seven villages. RESULTS: A total of 5,526 children from 3,724 households were enumerated, and 5,067 children (91.7%) were examined. The prevalence of uncorrected, presenting, and best visual acuity 0.5 (20/40) or worse in at least one eye was 2.9%, 2.8%, and 1.4%, respectively; 0.4% had best visual acuity 0.5 or worse in both eyes. Refractive error was the cause in 56% of the 200 eyes with reduced uncorrected vision, amblyopia in 9%, other causes in 19%, with unexplained causes in the remaining 16%. Myopia −0.5 diopter or less in either eye or hyperopia 2 diopters or greater was observed in less than 3% of children. Hyperopia risk was associated with female gender and myopia risk with older age. CONCLUSIONS: The prevalence of reduced vision is very low in school-age children in Nepal, most of it because of correctable refractive error. Further studies are needed to determine whether the prevalence of myopia will be higher for more recent birth cohorts.

PURPOSE: To assess the prevalence of refractive errors and vision impairment in school-age children in Shunyi District, northeast of Beijing, the Peoples Republic of China. METHODS: Random selection of village-based clusters was used to identify a sample of children 5 to 15 years of age. Resident registration books were used to enumerate eligible children in the selected villages and identify their current school. Ophthalmic examinations were conducted in 132 schools on children from 29 clusters during May 1988 to July 1998, including visual acuity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, ocular motility evaluation, and examination of the external eye, anterior segment, media, and fundus. Independent replicate measurements of all children with reduced vision and a sample of those with normal vision were done for quality assurance monitoring in three schools. RESULTS: A total of 6,134 children from 4,338 households were enumerated, and 5,884 children (95.9%) were examined. The prevalence of uncorrected, presenting, and best visual acuity 0.5 (20/40) or worse in at least one eye was 12.8%, 10.9%, and 1.8%, respectively; 0.4% had best visual acuity 0.5 or worse in both eyes. Refractive error was the cause in 89.5% of the 1,236 eyes with reduced vision, amblyopia in 5%, other causes in 1.5%, with unexplained causes in the remaining 4%. Myopia −0.5 diopter or less in either eye was essentially absent in 5-year-old children, but increased to 36.7% in males and 55.0% in females by age 15. Over this same age range, hyperopia 2 diopters or greater decreased from 8.8% in males and 19.6% in females to less than 2% in both. Females had a significantly higher risk of both myopia and hyperopia. CONCLUSIONS: Reduced vision because of myopia is an important public health problem in school-age children in Shunyi District. More than 9% of children could benefit from prescription glasses. Further studies are needed to determine whether the upward trend in the prevalence of myopia continues far beyond age 15 and whether the development of myopia is changing for more recent birth cohorts.

PURPOSE. To quantify and compare the reduction in quality of life due to visual impairment and angina using patient preferences (utilities). METHODS. Using a standard time tradeoff method, we obtained utilities for current vision, monocular and binocular blindness, current angina, and moderate angina in 60 patients with both vision problems and angina pectoris who sought care at the National Eye Institute (NEI), National Naval Medical Center, or Barnes-Jewish Hospital. Patients were characterized clinically based on visual acuity and the Duke Activity Status Index (DASI). Patients also completed a seven-item version of the NEI Visual Functioning Questionnaire and the SF-36 Health Survey Questionnaire. RESULTS. Patients had a median visual acuity of 20/100 in the worst eye, 20/40 in the better eye, and a median DASI of 24.2 (0 = severe functional limitations due to anginal symptoms, 58.2 = no limitations). There was substantial variation in utilities among patients. The average utility for current vision (...

PURPOSE: To estimate the prevalence of blindness and cataract surgery among older adults in rural China. METHODS: Cluster sampling was used in randomly selecting men and women aged 50 years or older for visual acuity testing and an eye examination in 28 villages in Shunyi County. The survey, which was carried out in the fall of 1996, was preceded by a pilot study in which operational methods were refined and quality assurance evaluations carried out. RESULTS: Of 5,555 enumerated subjects ≥50 years of age, 91.5% (5,084/5,555) were examined and 90.9% (5,052/5,555) were tested for visual acuity. In this population, 2.8% (139/5,052) were blind, defined as presenting visual acuity less than 6/60 in both eyes. Blindness was associated with older age and female sex. Cataract was the principal cause of blindness in at least one eye in 48.2% (67/139) of blind people. The ratio of those blind from cataract who were operated on to the those who could have been operated on, cataract surgical coverage, was estimated to be 47.8% (54/113). Cataract surgery was associated with younger age but not sex or education. CONCLUSIONS: Blindness, particularly blindness related to cataract, continues to be a significant problem among the elderly, especially women, in this population-based sample of rural Chinese. Despite an active eye-care program in Shunyi County, only half of those who might benefit from cataract surgery are receiving it.

PURPOSE: To measure visual acuity and vision-related quality of life in individuals in rural China operated on for cataract. METHODS: Five thousand fifty-two persons age 50 years and older, 90.9% (5,052/5,555) of a randomly selected population in Shunyi County, were examined in the fall of 1996. Visual functioning and quality of life questionnaires were administered to those with presenting visual acuity less than 6/60 in either eye and to those who were aphakic or pseudophakic. RESULTS: Of the 87 individuals operated on for cataract, 12% (10/87) had presenting visual acuity of 6/18 or more in both eyes, and 24.1% (21/87) had less than 6/60. Twenty-five percent (29/116) of the 116 eyes operated on for cataract had presenting visual acuity of 6/18 or more, and 44.8% (52/116) had less than 6/60. Aphakic cases without glasses and uncorrectable aphakia attributable to surgical complications were common. In a multivariate regression model, including time period of surgery, hospital type, and surgical procedure, only pseudophakia was associated with better outcomes ( P = .05). On a scale from 0 (maximum problems) to 100 (no problems), the mean visual functioning score (±SD) for the operated-on population was 61.9 ± 30.0, and 71.0 ± 31.8 for the quality of life questionnaire. These scores were comparable to those of the unoperated-on population with moderate bilateral blindness ( CONCLUSIONS: Both clinical and patient-reported cataract surgery outcomes are below what should be achievable. Improvement in outcomes must be given greater emphasis if the potential of cataract surgery in restoring sight is to be realized.

BACKGROUND—Visual acuity and vision related quality of life outcomes in cataract surgery were evaluated in a population based survey in two geographic zones in Nepal. METHODS—Case finding was based on random sampling using a stratified cluster design with door to door enumeration of people aged ⩾45 years followed by eye examinations at village sites. All aphakics/pseudophakics, those with visual acuity less than 6/60 in either eye, and a sample of those with normal visual acuity were administered visual functioning (VF) and quality of life (QOL) questionnaires. RESULTS—15% of the 159 cataract operated cases had presenting visual acuity ⩾6/18 in both eyes, 38% with best corrected visual acuity. 21% were still blind with presenting visual acuity

Purpose: To compare the effects of extracapsular cataract extraction with posterior chamber intraocular lens (ECCE/PC-IOL) vs intracapsular cataract extraction with aphakic glasses (ICCEAG) on everyday visual functioning and quality of life. Methods: In a nonmasked randomized controlled clinical trial, 3,400 bilateral vision-impaired patients, aged 40 to 75 years, with operable cataract were randomly assigned to receive one of the two treatment options. One half in each group were randomly selected for interviewer administration of visual functioning and quality of life questionnaires before surgery and at 6 and 12 months after surgery. Results: Both ICCE-AG and ECCE/PC-IOL produced dramatic improvements in visual functioning and quality of life scores. Patients receiving ECCE/PC-IOL reported larger beneficial changes than did those receiving ICCE-AG, compatible with additional beneficial effects of a moderate magnitude for visual functioning and of a smaller beneficial magnitude for quality of life. All between-group differences were highly statistically significant ( P Conclusions: In this developing-country setting, ICCE-AG and ECCE/PC-IOL were associated with substantial benefits in improved everyday vision function and vision-related quality of life. Patients who received ECCE/PC-IOL reported greater benefits and fewer problems with vision than did patients who received ICCE-AG.

Purpose: To evaluate the safety and efficacy of extracapsular cataract extraction with posterior chamber intraocular lens (ECCE/PC-IOL) compared with intracapsular cataract extraction with aphakic glasses (ICCE-AG). Methods: In a nonmasked randomized controlled clinical trial, 3,400 bilaterally visionimpaired patients aged 40 to 75 years with operable cataract were randomly assigned to receive either ICCE-AG or ECCE/PC-IOL at the Aravind Eye Hospital in India. The surgery was performed by one of four study surgeons. Patients were hospitalized for 5 postoperative days, with followup visits at 2, 6, and 12 months after discharge. Postsurgery evaluations were conducted by two independent study ophthalmologists. Results: At any single postoperative follow-up time point, there were no statistically significant differences of clinical relevance between treatment groups for any complication of a serious nature except cystoid macular edema, which was more common with ICCE (4.2% vs 1.6%). In general, whether of a trivial, intermediate, or serious nature, complication rates were low at each evaluation time point. Cumulatively, the incidence of serious complications of all types throughout the 1-year study period was 14.5% for patients in the ICCE-AG group and 7.7% in the ECCE group ( P ). Best-corrected visual acuity of 20/40 or better at 12 months was attained by 90.7% of ICCE-AG patients and 96.3% of ECCE/PC-IOL patients ( P ). Conclusions: Although both operative procedures are safe and effective for cataract patients with bilateral impairment, ECCE/PC-IOL is superior to ICCE-AG in terms of both visual acuity restoration and safety.

Purpose: To determine the use of eye care services by type of provider (ophthalmologist, optometrist, and non-ophthalmologist physician) in the Medicare population. Methods: As a basis for characterizing eye conditions and ophthalmic services among a population 65 years of age and older, 1991 claims from a representative 5% sample of Medicare beneficiaries were analyzed using a previously described classification scheme. Analysis was specifically conducted by type of provider as well as by the service provided. Results: Almost one half of the approximately 30 million Medicare beneficiaries 65 years of age or older received eye care services in 1991, resulting in more than 35,000,000 visits (claims). Ophthalmologists provided services to 71 % of this eye care population, and optometrists to 22%; 36% of this population received ophthalmic-related services from other providers, and 14% from only other providers (commonly for eye lid dermatitis and tumors). Cataract was the most common condition, accounting for 41 of visits to ophthalmologists (and 1.2 million cases of surgery), glaucoma accounted for 19% of visits, and retinal diseases for 14%. The visit percentages for optometrists are 58%, 8%, and 11 %, respectively. Ophthalmic examination and evaluation accounted for 63% of the 28,000,000 paid ophthalmologists' procedures, and 58% of the 5,500,000 optometrists' procedures. Conclusion: Optometrists and physicians other than ophthalmologists were the sole providers of ophthalmic-related services to a large percentage of beneficiaries who received eye care in 1991. Within the universe of service provided by ophthalmologists, the majority of all care consisted of evaluation and management services as opposed to surgical procedure-based care.

Clnical trial randomization schemes to control patient characteristics that can influence clinical response are not sufficient to control for their effects on operational efficiency and cost within the provider institution. This variation can result in biased economic findings when patients are allowed to select a provider themselves.

Pharmacokinetic models have been developed to assist in extrapolating results from rodent bioassays. However, in numerous circumstances, it is necessary to combine such models with cellular response models to fully define interspecies and dose extrapolations. Interactions between pharmacokinetic target tissue end points (DNA adduct formation) and cellular proliferation in liver and urinary bladder carcinogenesis is illustrated with the results from the ED01 study involving 2-acetylaminofluorene administered to female mice. The interaction of genotoxic and cell proliferative effects are also illustrated in a co-carcinogenesis study with low doses of N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide and high doses of sodium saccharin. The application of such interactions to humans is illustrated for the case of cigarette smoke-induced bladder cancer.

To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Ji'an county of Jiangxi province, China.It was a population-based cross-section study. Geographically defined cluster sampling was used in 5402 randomly selected individuals aged ≥ 50 years in 28 clusters in Ji'an from September to November 2006. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits. Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity.Five thousands four hundreds and two individuals were enumerated and 5010 persons were examined, the response rate was 92.74%. Based on the criteria of World Health Organization visual impairment classification in 1973, 78 persons were diagnosed as blindness, 265 persons were diagnosed as moderate and severe visual impairment defined as best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.56% and 5.29% respectively. Ninety-four persons were diagnosed as blindness, 726 persons were diagnosed as moderate and severe visual impairment defined as presenting visual acuity, the prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.88% and 14.50% respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 970.15, P = 0.000), female (χ(2) = 89.81, P = 0.000), and illiterate persons (trend χ(2) = 241.85, P = 0.000). Cataract was still the first leading cause of blindness and visual impairment, the retinal diseases was the second. Un-corrected refractive error also was the main cause of visual impairment.The prevalence of blindness and moderate and severe visual impairment was higher than other district in China. The first leading cause of blindness and visual impairment is still cataract.

To estimate the prevalence of cataract, the outcomes of cataract surgery, cataract surgical coverage rate, cataract blindness social burden rate in Ji'an county of Jiangxi province, China.Cluster sampling was used in randomly selected 5010 individuals aged ≥ 50 years in Ji'an county of Jiangxi province. All individuals were received visual acuity and eye examination, including the evaluation of lens status and cataract surgical status by slit lamp biomicroscopy. Data bank was established by Epi-info Software. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0 (Stata Corp, College Station, TX). Confidence intervals and P values (considered significance at the P0.05 level) for prevalence of cataract, cataract surgical coverage rate, cataract blindness social burden rate and outcomes of surgery were calculated with adjustment for clustering effects and stratification associated with the sampling design.In 5010 individuals, 1158 cases of cataract were found, the prevalence of cataract was 23.11% among adults aged 50 or above. The prevalence of cataract was higher in the aged, female (P0.01). In 99 eyes with cataract surgery, 50.51% and 5.05% of eyes were performed by the modern extra-capsular surgery and phacoemulsification respectively. The rate of intraocular lens implantation was 55.56%. Post-operative presenting and best corrected visual acuity equal to or more than 0.7 was 10.1% and 45.5% of operated eyes respectively. The main causes of the post-operated eyes with worse visual acuity were post-capsular opacity and refractive error. The cataract surgical coverage rate was 32.29%, and the cataract blindness social burden rate was 3.83%. The cataract surgical rate was lower and cataract blindness social burden rate was higher in the aged persons (P0.01).Cataract is the most common eye disease that may lead into blindness and severe visual impairment among older adults aged equal or more than 50 years. The cataract surgical coverage rate is not high but the cataract blindness social burden rate is heavy in Ji'an county. The rate of intraocular lens implantation need increase and the visual outcomes of the surgery should be further improved in the future.

To assess the prevalence of cataract, the outcomes of cataract surgery, the rate of cataract surgical coverage, and the rate of cataract blindness social burden.Cluster sampling was used in 5118 randomly selected individuals agedor = 50 years in the Shunyi district of Beijing from April to August 2006. All individuals were received visual acuity and eye examination, including the evaluation of lens status and cataract surgical status by slit lamp biomicroscopy. Data bank was established by Epi-info Software. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0 (Stata Corp, College Station,TX). Multiple logistic regression analysis was employed to analyzed the prevalence of cataract,cataract surgical coverage rate,cataract blindness social burden rate and outcomes of surgery among different ages, sex and educational background.In 5118 individuals, 797 cases of cataract were found, the prevalence of cataract was 15.57% among adults aged 50 or above. The prevalence of cataract was higher in the aged, female, illiterate persons (P0.01). In 189 eyes with cataract surgery, 65.08% and 23.28% of eyes were performed by the modern extra-capsular surgery and Phacoemulsification respectively. The rate of intraocular lens implantation was 89.42%. Post-operative presenting and best corrected visual acuity more than 0.7 was 30.16% and 61.38% of operated eyes respectively. The main causes of the post-operated eyes with worse visual acuity were post-capsular opacity and refractive error. The cataract surgical coverage rate was 62.22%, and the cataract blindness social burden rate was 2.64%. The cataract surgical rate was lower and cataract blindness social burden rate was higher in the aged persons (P0.01).Cataract is the most common eye disease that may lead into blindness and severe visual impairment among older adults aged equal or more than 50 years. The cataract surgical coverage rate is high in the Shunyi district, but still is lower in the aged persons. The visual outcomes of the surgery should be further improved in the future.

OBJECTIVE To assess the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in the Shunyi district of Beijing,China.It was a population-based cross-section study. Geographically defined cluster sampling was used in 5840 randomly selected individuals agedor = 50 years in 28 clusters in the Shunyi district from April to August 2006. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits. Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9. 0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity.Five thousands eight hundreds and forty individuals were recruited and 5118 persons were examined,the response rate was 87.64%. Based on the criteria of World Health Organization visual impairment classification in 1973,57 persons were diagnosed as blindness, 160 persons were diagnosed as moderate and severe visual impairment defined as best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.11% and 3.12% respectively. Sixty-five persons were diagnosed as blindness, 428 persons were diagnosed as moderate and severe visual impairment defined as presenting visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.27% and 8. 36% respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend Chi2 = 784.23, P = 0.000), female (Chi2 = 28.35, P = 0.000), and illiterate persons (trend Chi2 = 397.13, P = 0.000). Cataract was still the first leading cause of blindness and visual impairment, the retinal diseases was the second. Un-corrected refractive error also was the main cause of visual impairment.The prevalence of blindness and moderate and severe visual impairment has been decreasing among older adults aged 50 years or above in the Shunyi district since 1996. The first leading cause of blindness and visual impairment is still cataract.

To estimate the prevalence of blindness and low vision among older adults agedor = 50 years in Qidong City of Jiangsu Province, China, in 2006.Cluster sampling was used in randomly selecting 5662 individuals agedor = 50 years from September to December 2006 in 16 clusters in Qidong City. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits. Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity.Five thousands six hundreds and sixty-two individuals were recruited, the response rate was 90.80%. Based on the criteria of World Health Organization visual impairment classification in 1973,91 persons were diagnosed as blindness, 175 persons were diagnosed as moderate and severe visual impairment defined as best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.77% and 3.40% respectively. One hundred and thirteen persons were diagnosed as blindness, 354 persons were diagnosed as moderate and severe visual impairment defined as presenting visual acuity, the prevalence of blindness and moderate and severe visual impairment were 2.20% and 6.89% respectively. The prevalence of blindness and moderate and sever visual impairment was higher in aged (trend Chi2 = 825.16, P = 0.000), female (Chi2 = 19.85, P = 0.001), and illiterate persons (trend Chi2 = 329. 85, P = 0.000). The leading cause of blindness was cataract.Blindness and low vision are associated with older age and illiterates in Qidong City. According to presenting visual acuity, the causes leading to blindness and low vision are, in descending order, cataract, ocular fundus disease, refractive error and cornea disease.

To estimate the prevalence of cataract, the rate of cataract surgical coverage rate,and the rate of cataract-blindness social burden among older adults aged 50 years or above in Qidong City of Jiangsu Province, China, in 2006.Cluster sampling was used in randomly selected 5662 individuals aged 50 years or above in 16 clusters in Qidong City. 5141 individuals received visual acuity and eye examination from September to December 2006. Lens and cataract operation status were evaluated by slit lamp. Multiple logistic regression analysis was employed to analyzed the prevalence of cataract, cataract surgical coverage rate, cataract blindness social burden rate and outcomes of surgery among different ages, sex and educational background.In 5141 individuals, 1098 cases of cataract were found, the prevalence of cataract was 21.35% among adults aged 50 or above. The prevalence of cataract was higher in the aged, female, illiterate persons (P0.01). In 89 eyes with cataract surgery, 25.84% and 42.70% of eyes were performed by the modern extra-capsular surgery and Phacoemulsification respectively. The rate of intraocular lens implantation was 69. 66%. Post-operative presenting and best corrected visual acuity more than 0.7 was 24.70% and 48.31% of operated eyes respectively. The main causes of the post-operated eyes with worse visual acuity were retinal disorders post-capsular opacity and glaucoma. The cataract surgical coverage rate was 37.96%, and the cataract blindness social burden rate was 2.10%. The cataract blindness social burden rate was higher in the aged persons (P0.01).Cataract is the most common and important eye disease that may lead into blindness and severe visual impairment among older adults aged 50 years or above. The cataract surgical coverage rate is not so high in Qidong City, and even lower in the aged persons. The first important task in blindness prevention still is the elimination of cataract blindness. The visual outcomes of the cataract surgery should be further improved in the future.

Introduction: Presbyopia is an important cause of avoidable visual disability. Objective: To estimate the prevalence of near vision impairment and spectacle coverage among middle and older-aged adults in rural Nepal. Materials and methods: The surveys was carried out among the people of age 35 and over in randomly-selected cluster samples in rural settings of Kaski district of western Nepal, Near visual acuity, with and without presenting near correction, was measured at 40 cm using a LogMAR near vision tumbling E chart under ambient indoor lighting. Subjects with uncorrected binocular distance vision of 20/40 or worse were refracted and those with near vision of 20/40 or worse tested with plus sphere to obtain the best-corrected binocular near visual acuity. Results: A total of 2,360 persons aged 35 years and over were enumerated and 2,156 (91.3 %) were examined. The age- and gender-standardized prevalence of uncorrected near visual impairment (vision of 20/40 or worse) in study population was found to be 66.1 %. Near vision could not be corrected (>20/40) even after distance and near vision correction in 6.4 % . Using the multiple logistic regression models, uncorrected visual impairment was associated with an older age (odds ratio [OR] = 1.13, P < 0.001) and a lower educational level (OR = 1.11, P = 0.01) was less associated with female gender (OR = 0.72, P = 0.038). Over 90 % of people with near visual impairment did not have spectacles. Conclusion: The prevalence of presbyopia appears to be higher with an earlier onset and over 90 % of people in need of near correction do not have spectacles in this setting. DOI: http://dx.doi.org/10.3126/nepjoph.v4i1.5845 NEPJOPH 2012; 4(1): 17-22

To design the protocol of the China nine-province survey for blindness, visual impairment and cataract surgery to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery.The protocol design was began after accepting the task for the national survey for blindness, visual impairment and cataract surgery from the Department of Medicine, Ministry of Health, China, in November, 2005. The protocol in Beijing Shunyi Eye Study in 1996 and Guangdong Doumen County Eye Study in 1997, both supported by World Health Organization, was taken as the basis for the protocol design. The relative experts were invited to discuss and prove the draft protocol. An international advisor committee was established to examine and approve the draft protocol. Finally, the survey protocol was checked and approved by the Department of Medicine, Ministry of Health, China and Prevention Program of Blindness and Deafness, WHO.The survey protocol was designed according to the characteristics and the scale of the survey. The contents of the protocol included determination of target population and survey sites, calculation of the sample size, design of the random sampling, composition and organization of the survey teams, determination of the examinee, the flowchart of the field work, survey items and methods, diagnostic criteria of blindness and moderate and sever visual impairment, the measures of the quality control, the methods of the data management.The designed protocol became the standard and practical protocol for the survey to evaluate the prevalence and main causes of blindness and visual impairment, and the prevalence and outcomes of the cataract surgery.

Objective To compare outcomes between adjustable spectacles and conventional methods for refraction in young people. Design Cross sectional study. Setting Rural southern China. Participants 648 young people aged 12-18 (mean 14.9 (SD 0.98)), with uncorrected visual acuity ≤6/12 in either eye. Interventions All participants underwent self refraction without cycloplegia (paralysis of near focusing ability with topical eye drops), automated refraction without cycloplegia, and subjective refraction by an ophthalmologist with cycloplegia. Main outcome measures Uncorrected and corrected vision, improvement of vision (lines on a chart), and refractive error. Results Among the participants, 59% (384) were girls, 44% (288) wore spectacles, and 61% (393/648) had 2.00 dioptres or more of myopia in the right eye. All completed self refraction. The proportion with visual acuity ≥6/7.5 in the better eye was 5.2% (95% confidence interval 3.6% to 6.9%) for uncorrected vision, 30.2% (25.7% to 34.8%) for currently worn spectacles, 96.9% (95.5% to 98.3%) for self refraction, 98.4% (97.4% to 99.5%) for automated refraction, and 99.1% (98.3% to 99.9%) for subjective refraction (P=0.033 for self refraction v automated refraction, P=0.001 for self refraction v subjective refraction). Improvements over uncorrected vision in the better eye with self refraction and subjective refraction were within one line on the eye chart in 98% of participants. In logistic regression models, failure to achieve maximum recorded visual acuity of 6/7.5 in right eyes with self refraction was associated with greater absolute value of myopia/hyperopia (P