RETINITIS PIGMENTOSA ASSOCIATED WITH THE EYS C2139Y VARIANT : An Important Cause of Blindness in East Asian Populations.

PURPOSE: The study aimed to describe the phenotypic features of retinitis pigmentosa (RP) associated with the previously described EYS C2139Y variant in Singaporeans and establish the importance of this variant as a prevalent cause of RP among East Asians. METHODS: A clinical phenotyping and exome-sequencing study was conducted on consecutive patients with nonsyndromic RP. Epidemiological analysis was performed using Singaporean and global population-based genetic data. RESULTS: A study of 150 consecutive unrelated individuals with nonsyndromic RP found that 87 (58%) of cases had plausible genotypes. A previously described missense variant in the EYS gene, 6416G>A (C2139Y), occurred heterozygously or homozygously in 17 of 150 families (11.3%), all with autosomal recessive RP. Symptom onset in EYS C2139Y-related RP ranged from 6 to 45 years, with visual acuity ranging from 20/20 at 21 years to no light perception by 48 years. C2139Y-related RP had typical findings, including sectoral RP in cases with EYS E2703X in trans . The median age at presentation was 45 years and visual fields declined to less than 20° (Goldmann V4e isopter) by age 65 years. Intereye correlation for visual acuity, fields, and ellipsoid band width was high (r 2 = 0.77-0.95). Carrier prevalence was 0.66% (allele frequency of 0.33%) in Singaporean Chinese and 0.34% in East Asians, suggesting a global disease burden exceeding 10,000 individuals. CONCLUSION: The EYS C2139Y variant is common in Singaporean RP patients and other ethnic Chinese populations. Targeted molecular therapy for this single variant could potentially treat a significant proportion of RP cases worldwide.

Vascular endothelial growth factor inhibitors for predominantly Caucasian myopic choroidal neovascularization: 2-year treatment outcomes in clinical practice: data from the Fight Retinal Blindness! Registry.

PURPOSE: To report the 24-month outcomes of vascular endothelial growth factor (VEGF) inhibitors for myopic choroidal neovascularization (mCNV) in predominantly Caucasian eyes in routine clinical practice. METHODS: Retrospective analysis of treatment-naïve eyes starting intravitreal injection of VEGF inhibitors of either bevacizumab (1.25 mg) or ranibizumab (0.5 mg) for mCNV from 1 January 2006 to 31 May 2018 that were tracked in the Fight Retinal Blindness! registry. RESULTS: We identified 203 eyes (bevacizumab-85 and ranibizumab-118) of 189 patients. The estimated mean (95% CI) change in VA over 24 months for all eyes using longitudinal models was +8 (5, 11) letters with a median (Q1, Q3) of 3 (2, 5) injections given mostly during the first year. The estimated mean change in VA at 24 months was similar between bevacizumab and ranibizumab [+9 (5, 13) letters for bevacizumab versus +9 (6, 13) letters for ranibizumab; p = 0.37]. Both agents were also similar in the mCNV activity outcomes, treatment frequency and visit frequency. CONCLUSIONS: The 24-month treatment outcomes of VEGF inhibitors for mCNV were favourable in this largest series yet reported of predominantly Caucasian eyes in routine clinical practice, with approximately two lines of visual gain and a median of three injections given mostly during the first year. These outcomes are similar to those reported for predominantly Asian eyes. Bevacizumab appeared to be as safe and effective as ranibizumab.

Working Towards Eye Health Equity for Indigenous Australians with Diabetes.

Type 2 diabetes mellitus (T2DM) poses significant challenges to individuals and broader society, much of which is borne by disadvantaged and marginalised population groups including Indigenous people. The increasing prevalence of T2DM among Indigenous people has meant that rates of diabetes-related complications such as blindness from end-stage diabetic retinopathy (DR) continue to be important health concerns. Australia, a high-income and resource-rich country, continues to struggle to adequately respond to the health needs of its Indigenous people living with T2DM. Trends among Indigenous Australians highlight that the prevalence of DR has almost doubled over two decades, and the prevalence of diabetes-related vision impairment is consistently reported to be higher among Indigenous Australians (5.2%-26.5%) compared to non-Indigenous Australians (1.7%). While Australia has collated reliable estimates of the eye health burden owing to T2DM in its Indigenous population, there is fragmentation of existing data and limited knowledge on the underlying risk factors. Taking a systems approach that investigates the social, environmental, clinical, biological and genetic risk factors, and-importantly-integrates these data, may give valuable insights into the most important determinants contributing to the development of diabetes-related blindness. This knowledge is a crucial initial step to reducing the human and societal impacts of blindness on Indigenous Australians, other priority populations and society at large.

Patterns and Risk Factor Profiles of Visual Loss in a Multiethnic Asian Population: The Singapore Epidemiology of Eye Diseases Study.

PURPOSE: To describe the pattern and risk factor traits associated with visual loss (defined as either visual impairment [VI] or blindness) in a multiethnic Asian cohort of Malay, Indian, and Chinese individuals living in Singapore. METHODS: A total of 10 020 participants from the Singapore Epidemiology of Eye Diseases Study were examined between 2004 and 2011. All underwent standardized examinations. VI (visual acuity <20/40 to ≥20/200) and blindness (visual acuity <20/200) were defined based on the US definition, better-seeing eye. Singapore Population Census 2010 was used to calculate age-standardized prevalence. Multiple logistic regression analysis was performed to determine the independent and joint risk factors associated with visual loss. RESULTS: Malay individuals had higher age-standardized prevalence of best-corrected and presenting VI (5.4% and 19.9%, respectively) than Indian (3.6% and 18.0%) and Chinese individuals (3.3% and 17.2%). Cataract was the main cause for presenting and best-corrected blindness; cataract and diabetic retinopathy were the top causes for best-corrected VI, consistently observed across the 3 ethnic groups. Older age, female sex, lower socioeconomic status, diabetes, systemic comorbidities, and cognitive impairment were independently associated with increased risk of best-corrected visual loss (all P ≤ .027). Individuals aged ≥60 years with diabetes were 12.7 times (95% confidence interval, 8.39-19.23) likely to have best-corrected visual loss, compared with younger, nondiabetic individuals. Lower income and education explained 58.1% and 23.2% of best-corrected visual loss in this population, respectively. CONCLUSION: In this urban multiethnic Asian population, we identified common traits associated with visual loss across Malay, Indian, and Chinese individuals. These results will be useful for the planning and designing of eye health services and strategies for Asia's rapidly developing populations living in urban communities. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Cataract Surgical Coverage and Visual Acuity Outcomes in Rural China in 2014 and Comparisons With the 2006 China Nine-Province Survey.

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 (<20/200) was 62.7% overall, ranging from 43.4% to 83.6% across the 9 study sites. Unoperated cataract was significantly associated with older age, female sex, and lack of education. Presenting visual acuity outcomes ≥ 20/63 in cataract-operated eyes was 62.2% overall, ranging from 51.6% to 78.6%, and 75.2%, ranging from 67.1% to 81.5%, with best-corrected visual acuity. As a proportional percentage of cataract surgical coverage in 2006, overall surgical coverage increased by 81.4% during the 2006-2014 interval, and by 110% when adjusted for visual acuity outcomes ≥ 20/63. CONCLUSIONS: Cataract blindness control is well underway in rural China, as evidenced by significant increases in cataract surgical coverage and improvement in visual acuity outcomes during the 2006-2014 interval. Further efforts are needed to provide greater access to affordable cataract surgery for the elderly, female persons, and those with little or no education.

CCDC102B confers risk of low vision and blindness in high myopia.

The incidence of high myopia is increasing worldwide with myopic maculopathy, a complication of myopia, often progressing to blindness. Our two-stage genome-wide association study of myopic maculopathy identifies a susceptibility locus at rs11873439 in an intron of CCDC102B (P = 1.77 × 10-12 and Pcorr = 1.61 × 10-10). In contrast, this SNP is not significantly associated with myopia itself. The association between rs11873439 and myopic maculopathy is further confirmed in 2317 highly myopic patients (P = 2.40 × 10-6 and Pcorr = 1.72 × 10-4). CCDC102B is strongly expressed in the retinal pigment epithelium and choroids, where atrophic changes initially occur in myopic maculopathy. The development of myopic maculopathy thus likely exhibits a unique background apart from the development of myopia itself; elucidation of the roles of CCDC102B in myopic maculopathy development may thus provide insights into preventive methods for blindness in patients with high myopia.

Prevalence and causes of blindness, visual impairment among different ethnical minority groups in Xinjiang Uygur autonomous region, China.

BACKGROUND: The aim of this cross-sectional study is to ascertain the prevalence and causes of blindness, visual impairment, uptake of cataract surgery among different ethnic groups in Xinjiang Uygur Autonomous Region, China. METHODS: Four thousand one hundred fifty people at 50 years and above from different minority ethnic groups were randomly selected for an eye examination. The four trained eye teams collected data using tumbling E visual chart, torch, portable slit lamp and direct ophthalmoscope in 2015. The World Health Organization's definition of blindness and visual impairment (VI) was used to classify patients in each ethnic group. Data were analyzed by different minority groups and were compared with Han Chinese. RESULTS: 3977 (95.8%) out of 4150 people were examined. The prevalence of blindness from the study population was 1.7% (95% confidence interval: 1.3-2.2%).There was no significant difference in prevalence of blindness between Han Chinese and people of Khazak and other minority ethnic groups, nor, between male and female. Cataract was the leading course (65.5%) of blindness and uncorrected refractive error was the most common cause of VI (36.3%) followed by myopic retinopathy. The most common barrier to cataract surgery was lack of awareness of service availability. CONCLUSIONS: This study documented a low blindness prevalence among people aged 50 years and over comparing to prevalence identified through studies of other regions in China. It still indicates blindness and un-operated cataract as the significant public health issue, with no evidence of eye health inequalities, but some inequities in accessing to cataract surgery amongst ethnic minority groups in Xinjiang.

Turning a blind eye: HTLV-1-associated uveitis in Indigenous adults from Central Australia.

PURPOSE: We describe the first two cases of HTLV-1 associated uveitis to be associated with HTLV-1c subtype infection. METHODS: Case report. RESULTS: Uveitis was demonstrated in two Indigenous Australian men, both of whom had high HTLV-1c proviral loads in peripheral blood. Visual outcomes were poor in each case. CONCLUSION: Clinicians should be aware of HTLV-1c infection as a cause of uveitis in Australia, and HTLV-1 serology should be included in the basic uveitis work-up in HTLV-1-endemic areas.

The Prevalence and Causes of Vision Loss in Indigenous and Non-Indigenous Australians: The National Eye Health Survey.

PURPOSE: To conduct a nationwide survey on the prevalence and causes of vision loss in Indigenous and non-Indigenous Australians. DESIGN: Nationwide, cross-sectional, population-based survey. PARTICIPANTS: Indigenous Australians aged 40 years or older and non-Indigenous Australians aged 50 years and older. METHODS: Multistage random-cluster sampling was used to select 3098 non-Indigenous Australians and 1738 Indigenous Australians from 30 sites across 5 remoteness strata (response rate of 71.5%). Sociodemographic and health data were collected using an interviewer-administered questionnaire. Trained examiners conducted standardized eye examinations, including visual acuity, perimetry, slit-lamp examination, intraocular pressure, and fundus photography. The prevalence and main causes of bilateral presenting vision loss (visual acuity <6/12 in the better eye) were determined, and risk factors were identified. MAIN OUTCOME MEASURES: Prevalence and main causes of vision loss. RESULTS: The overall prevalence of vision loss in Australia was 6.6% (95% confidence interval [CI], 5.4-7.8). The prevalence of vision loss was 11.2% (95% CI, 9.5-13.1) in Indigenous Australians and 6.5% (95% CI, 5.3-7.9) in non-Indigenous Australians. Vision loss was 2.8 times more prevalent in Indigenous Australians than in non-Indigenous Australians after age and gender adjustment (17.7%, 95% CI, 14.5-21.0 vs. 6.4%, 95% CI, 5.2-7.6, P < 0.001). In non-Indigenous Australians, the leading causes of vision loss were uncorrected refractive error (61.3%), cataract (13.2%), and age-related macular degeneration (10.3%). In Indigenous Australians, the leading causes of vision loss were uncorrected refractive error (60.8%), cataract (20.1%), and diabetic retinopathy (5.2%). In non-Indigenous Australians, increasing age (odds ratio [OR], 1.72 per decade) and having not had an eye examination within the past year (OR, 1.61) were risk factors for vision loss. Risk factors in Indigenous Australians included older age (OR, 1.61 per decade), remoteness (OR, 2.02), gender (OR, 0.60 for men), and diabetes in combination with never having had an eye examination (OR, 14.47). CONCLUSIONS: Vision loss is more prevalent in Indigenous Australians than in non-Indigenous Australians, highlighting that improvements in eye healthcare in Indigenous communities are required. The leading causes of vision loss were uncorrected refractive error and cataract, which are readily treatable. Other countries with Indigenous communities may benefit from conducting similar surveys of Indigenous and non-Indigenous populations.

Black patients sustain vision loss while White and South Asian patients gain vision following delamination or segmentation surgery for tractional complications associated with proliferative diabetic retinopathy.

PurposeThis retrospective comparative case series aims to determine whether patient ethnicity (White versus South Asian versus Black) is related to the outcome of surgical treatment for traction complications of severe proliferative diabetic retinopathy (PDR).SettingMoorfields Eye Hospital London, UK.MethodsAll patients who underwent vitrectomy with, delamination and/or segmentation for PDR over a 5-year period (2009-2014) were reviewed retrospectively. Patients were divided into White, South Asian or Black groups, and their age, gender, HbA1C and type of diabetes were recorded. A total of 484 patients (253 White, 117 South Asian, 114 Black) were included. Twenty-one patients were excluded due to inadequate documentation.OutcomesLogMAR Visual acuity (converted from Snellen) (VA), was recorded pre-operatively and ~6 months post surgery (range 5-8 months). Surgical outcome was classified according to the type and duration of tamponade required post-operatively.ResultsPre-operative VA and HbA1C values were similar across all three ethnic groups (P=0.64 and 0.569, respectively). Change in VA (mean±SD) was 0.41±0.78, 0.14±0.76 and -0.26±0.57 in White, South Asian and Black patient groups respectively (P<0.001). Multiple regression analysis showed that post-op VA was significantly related to race and pre-op VA only (both P<0.001). The Black patient group were more likely to require silicone oil tamponade (P<0.001) and long-term retention of silicone oil (P<0.001) than the White and South Asian patient groups.ConclusionsThis study demonstrates that Black patients on average lose vision following delamination surgery for traction complications of PDR while White and South Asian patients gain vision. The same group is also at higher risk of retaining silicone more than 6 months after surgery. This difference remains even when corrected for glycaemic control. The higher risk of visual loss and long-term retention of silicone oil in black patients requires further investigation. If these results are confirmed, surgeons should consider their patients' ethnicity before proceeding with surgical treatment of diabetic tractional detachment.

Ethnicity and Deprivation are Associated With Blindness Among Adults With Primary Glaucoma in Nigeria: Results From the Nigeria National Blindness and Visual Impairment Survey.

PURPOSE: We explored the risk factors for glaucoma blindness among adults aged 40 years and above with primary glaucoma in Nigeria. PARTICIPANTS AND METHODS: A total of 13,591 participants aged 40 years and above were examined in the Nigeria Blindness Survey; 682 (5.02%; 95 CI, 4.60%-5.47%) had glaucoma by ISGEO's criteria. This was a case-control study (n=890 eyes of 629 persons): glaucoma blind persons were cases and glaucoma not-blind were controls. Education and occupation were used to determine socioeconomic status scores, which were divided into 3 tertiles (affluent, medium, deprived). We assessed sociodemographic, biophysical, and ocular factors by logistic regression analysis for association with glaucoma blindness. Multinomial regression analysis was also performed with nonglaucoma as the reference category. RESULTS: A total of 119/629 (18.9%; 95% CI, 15.9%-22.4%) persons were blind in both eyes; 510 were controls. There was interethnic variation in odds of blindness; age, male sex, socioeconomic status, prior diagnosis of glaucoma, hypertension, intraocular pressure, and lens opacity were associated with glaucoma blindness. Axial length, mean ocular perfusion pressure, and angle-closure glaucoma were associated with blind glaucoma eyes. In multivariate analysis, Igbo ethnicity (OR=2.79; 95% CI, 1.03-7.57) had higher risk as was being male (OR=4.59; 95% CI, 1.73-12.16) and unmarried (OR=2.50; 95% CI, 1.03-6.07). Deprivation (OR=3.57; 95% CI, 1.46-8.72), prior glaucoma diagnosis (OR=5.89; 95% CI, 1.79-19.40), and intraocular pressure (OR=1.07; 95% CI, 1.04-1.09) were also independent risk factors for glaucoma blindness. CONCLUSION: Approximately 1 in 5 people with primary glaucoma were blind. Male sex, ethnicity and deprivation were strongly associated with blindness. Services for glaucoma need to improve in Nigeria, focusing on poor communities and men.

Risk Factors Associated with Progression to Blindness from Primary Open-Angle Glaucoma in an African-American Population.

PURPOSE: To determine the risk factors associated with progression to blindness from primary open-angle glaucoma (POAG) in an African-American population. METHODS: This study examined 2119 patients enrolled in the Primary Open-Angle African-American Glaucoma Genetics (POAAGG) study. A total of 59 eyes were identified as legally blind as a result of POAG (cases) and were age-and sex-matched to 59 non-blind eyes with glaucoma (controls). Chart reviews were performed to record known and suspected risk factors. RESULTS: Cases were diagnosed with POAG at an earlier age than controls (p = 0.005). Of the 59 eyes of cases, 16 eyes (27.1%) presented with blindness at diagnosis. Cases had worse visual acuity (VA) at diagnosis (p < 0.0001), with VA worse than 20/40 conferring a 27 times higher risk of progression to blindness (p = 0.0005). Blind eyes also demonstrated more visual field defects (p = 0.01), higher pre-treatment intraocular pressure (IOP; p < 0.0001), and higher cup-to-disc ratio (p = 0.006) at diagnosis. IOP was less controlled in cases, and those with IOP ≥21 mmHg at more than 20% of follow-up visits were 73 times more likely to become blind (p < 0.0001). Cases missed a greater number of appointments per year (p = 0.003) and had non-adherence issues noted in their charts more often than controls (p = 0.03). However, other compliance data did not significantly differ between groups. CONCLUSION: Access to care, initial VA worse than 20/40, and poor control of IOP were the major risk factors associated with blindness from POAG. Future studies should examine earlier, more effective approaches to glaucoma screening as well as the role of genetics in these significantly younger patients who progress to blindness.

Prevalence and Causes of Visual Impairment and Blindness in Chinese American Adults: The Chinese American Eye Study.

IMPORTANCE: Visual impairment (VI) and blindness continue to be major public health problems worldwide. Despite previously published studies on VI in Chinese and other racial/ethnic populations, there are no data specific to Chinese American adults. OBJECTIVES: To determine the age- and sex-specific prevalence and causes of VI and blindness in adult Chinese Americans and to compare the prevalence to other racial/ethnic groups. DESIGN, SETTING, AND PARTICIPANTS: In this population-based, cross-sectional study of 10 US Census tracts in the city of Monterey Park, California, 4582 Chinese American adults 50 years and older underwent complete ophthalmologic examinations, including measurement of presenting and best-corrected visual acuity (BCVA) for distance using the Early Treatment Diabetic Retinopathy Study protocol from February 1, 2010, through October 31, 2013. MAIN OUTCOMES AND MEASURES: Age-specific prevalence and causes of VI and blindness for presenting and BCVA. RESULTS: Of the 5782 eligible adults, 4582 (79.2%) completed an in-clinic eye examination. Of the 4582 participants, most were born in China (3149 [68.7%]), female (2901 [63.3%]), and married (3458 [75.5%]). The mean (SD) age was 61 (9) years. The prevalence of presenting VI was 3.0% (95% CI, 2.5%-3.5%), with 60.0% of this prevalence being attributed to uncorrected refractive error. The overall age-adjusted prevalence for VI (BCVA of ≤20/40 in the better eye) was 1.2% (95% CI, 0.9%-1.5%). The overall age-adjusted prevalence of blindness (BCVA of ≤20/200 in the better-seeing eye) was 0.07% (95% CI, 0%-0.2%). The prevalence of VI and blindness was higher in older Chinese Americans compared with younger. The primary causes of VI were cataracts and myopic retinopathy; the primary cause of blindness was myopic retinopathy. CONCLUSIONS AND RELEVANCE: The prevalence of VI in Chinese Americans is similar to that of non-Hispanic white and Latino individuals in the United States and similar to or lower than the prevalence previously reported for Chinese adults from non-US studies. The prevalence of blindness is lower than that noted in other US or non-US studies. Myopic retinopathy is a frequent cause of VI and blindness in Chinese Americans that has not been commonly observed in other racial/ethnic groups. Because myopia frequently develops at a young age, Chinese Americans should be educated regarding the importance of regular screening of preschool and school-aged children to reduce the development and progression of myopia.

Disparities in Vision Loss Due to Cataracts in Hispanic Women in the United States.

PURPOSE: To review the current literature on the prevalence of cataract in Hispanic females living in the United States. METHODS: Review relevant literature on cataract, eye disease, and health practices of Hispanics living in the U.S. RESULTS: Females comprise 64.5% of blind persons worldwide. Internationally, female gender is associated with lower awareness of cataract and other diseases of the eye and women are less likely to have cataract surgery than men in low- and middle-income countries. CONCLUSION: Hispanic women receive disparate care compared to their male counterparts. The etiology of this is likely multifactorial but possible contributors include genetics, gender roles, and personal healthcare decisions. Interventions to address this disparity should be targeted, efficient, and sustainable.

Pervasive Blindness and ocular morbidity in the Chepang people of Nepal.

Blindness, which is a major burden on the individual and the society, was observed to be pervasively present in a region inhabited by an undermined, disadvantaged ethnic people, the Chepang (Köberlein et al., 2013). Such a plight heralds escalating, already- fragile eye health care in the remote region of Nepal (Ghimire, 2015).

Design and baseline characteristics of a population-based study of eye disease in southern Chinese people: the Dongguan Eye Study.

BACKGROUND: To describe the study design, methodology and baseline characteristics of the Dongguan Eye Study. DESIGN: Population-based, cross-sectional study PARTICIPANTS: A total of 8952 rural-dwelling residents aged 40 years or older in Hengli, Dongguan. METHODS: The Dongguan Eye Study was conducted from September 2011 to February 2012. The interview covered demographic data, socio-economic status and health- and vision-related quality of life. Physical measurements included height, weight, waist and hip circumference, heart rate and blood pressure. Laboratory tests included fasting blood glucose, haemoglobin A1c, oral glucose tolerance, serum total cholesterol, triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, serum creatinine, blood urea nitrogen and uric acid. Ophthalmic examinations included visual acuity and autorefraction testing, intraocular pressure measurement, slit-lamp examination, ocular biometry, gonioscopy, fundus photography, retinal nerve fibre layer imaging and visual field testing. MAIN OUTCOME MEASURES: Prevalence and risk factors for visual impairment, blindness, eye diseases and their associations with systemic medical indicators or health-related lifestyles, as well as epidemiological data on diabetic subjects. Methodology, response rates and baseline characteristics are presented. RESULTS: Of the 11 357 individuals eligible for the Dongguan Eye Study, 8952 (78.82%) subjects participated. All participants were self-identified Han Chinese. The average age was 54.0 years, 59.9% were female, 48.4% were farmers and 77.2% had elementary or junior middle school educational levels. The average body mass index and waist-hip ratio were 24.6 ± 3.9 kg/m(2) and 0.9 ± 0.2. CONCLUSIONS: Data from the Dongguan Eye Study provide information concerning the prevalence, risk factors and impacts of eye diseases in rural residents undergoing urbanization in southern China.

Prevalence and Causes of Visual Impairment in a Chinese Adult Population: The Taizhou Eye Study.

PURPOSE: To study the current prevalence and causes of low vision and blindness in an adult Chinese population. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: We used a random cluster sampling method and evaluated 10 234 eligible subjects ≥45 years old (response rate, 78.1%) in the Taizhou Eye Study. METHODS: Examinations were performed from July 2012 through December 2013. Participants underwent a detailed examination, including uncorrected visual acuity, best-corrected visual acuity (BCVA), intraocular pressure, axial length, slit-lamp, and fundus examinations to evaluate the prevalence and primary causes of visual impairment (VI). MAIN OUTCOME MEASURES: We defined low vision and blindness according to the World Health Organization (WHO) criteria (low vision: BCVA, <20/63-≥20/400; blindness: BCVA, <20/400 in the better eye) and United States criteria (low vision: BCVA, <20/40-≥20/200; blindness: BCVA, <20/200 in the better eye). RESULTS: Using the WHO BCVA criteria, the standardized prevalence of bilateral low vision and blindness were 5.1% and 1.0%, respectively. Using the United States BCVA criteria, the standardized prevalence were 12.8% and 1.5%, respectively. Using the WHO criteria, the primary causes of bilateral low vision and blindness were cataract (59.1% and 48.5%, respectively), myopic macular degeneration (17.6% and 17.2%, respectively), and age-related macular degeneration (11.6% and 10.1%, respectively). The primary causes of monocular low vision were cataract (55.6%), age-related macular degeneration (12.6%), and myopic macular degeneration (8.9%), whereas those of monocular blindness were cataract (46.8%), atrophy of eyeball or prosthetic eye (10.2%), and cornea opacity (7.3%). A further analysis revealed that in adults 45-59 years old, myopic macular degeneration (59.6% and 27.2%, respectively) and cataract (13.8% and 23.4%, respectively) were the leading causes of bilateral and monocular VI. In adults ≥60 years old, cataract (66.8% and 61.2%, respectively) and age-related macular degeneration (12.6% and 11.8%, respectively) were the primary causes of bilateral and monocular VI. CONCLUSIONS: The prevalence of low vision and blindness in Chinese adults remains a severe public health problem. In the Taizhou Eye Study, cataract was the leading cause of low vision and blindness. Myopic macular degeneration and cataract were the primary causes of VI in adults 45-59 years and ≥60 years old, respectively.