Prevalence and causes of vision loss in East Asia: 1990–2010

The burden, causes, and determinants of blindness and vision impairment in Asia: An analysis of the Global Burden of Disease Study

Background

Asia accounts for more than half of the world's population and carries a substantial proportion of the global burden of blindness and vision impairment. Characterising this burden, as well as its causes and determinants, could help with devising targeted interventions for reducing the occurrence of blindness and visual impairment.

Methods

Using the Global Burden of Disease Study 2019 database, we retrieved data on the number of disability-adjusted life years (DALYs); crude and age-standardised rates; and the prevalence (with 95% uncertainty intervals (95%UIs)) of blindness and vision loss due to six causes (age-related macular degeneration, cataracts, glaucoma, near-vision impairment, refractive error, and other vision loss) for Asian countries for the period between 1990 and 2019. We defined DALYs as the sum of the years lost due to disability and years of life lost, and calculated age-standardised figures for the number of DALYs and prevalence by adjusting for population size and age structure. We then evaluated the time trend of the disease burden and conducted subgroup analyses by gender, age, geographic locations, and socio-demographic index (SDI).

Results

In 2019, the DALYs and prevalence of blindness and vision loss had risen by 90.1% and 116% compared with 1990, reaching 15.84 million DALYs (95% UI = 15.83, 15.85) and 506.71 million cases (95% UI = 506.68, 506.74). Meanwhile, the age-standardised rate of DALYs decreased from 1990 to 2019. Cataracts, refractive error, and near vision impairment were the three most common causes. South Asia had the heaviest regional disease burden (age-standardised rate of DALYs = 517 per 100 000 population; 95% UI = 512, 521). Moreover, the burden due to cataracts ranked high in most Asian populations. Being a woman; being older; and having a lower national SDI were factors associated with a greater vision loss burden.

Conclusions

The burden due to vision loss remains high in Asian populations. Cataracts, refractive error, and near vision loss were the primary causes of blindness and vision loss. Greater investment in ocular disease prevention and care by countries with lower socioeconomic status is needed, as well as specific strategies targeting cataract management, women and the elderly.

Diversity in enrollment to clinical trials for cataract medicine and surgery: meta-analysis

PURPOSE

To investigate sex, racial, and ethnic disparities in patient enrollment across cataract trials registered in the United States.

SETTING

Participants enrolled in high-quality (reduced risk of bias), U.S.-registered (on ClinicalTrials.gov ), cataract-related randomized controlled trials (RCTs). RCTs must be completed, have used double or greater masking, and have published results through the registry or a scholarly journal.

DESIGN

Cross-sectional database study.

METHODS

Trial (study sponsor country, study site location, trial initiation year, study phase, and study masking) and demographic data (sex, race, and ethnicity according to U.S. reporting guidelines) were collected. The Global Burden of Disease database provided sex-based cataract disease burdens. Pooled participation-to-prevalence ratios (PPRs) with 95% CIs were calculated for female sex, with values between 0.8 and 1.2 constituting sufficient study enrollment. Kruskal-Wallis tests (α = 0.05) with subsequent post hoc comparisons were used to evaluate demographic representations stratified by trial characteristics.

RESULTS

From 864 records, 100 clinical trials (N = 67 874) were identified, of which 97 (N = 67 697) reported sex demographics with a pooled female PPR of 0.89 (95% CI, 0.85-0.94). Of the 67 697 total participants, the absolute female enrollment was 19 062 (28.16%). Ethnicity and race were reported in 9 (N = 1792) and 26 trials (N = 23 181), respectively. Among trials that reported race, most were White (N = 19 574; 84.44%).

CONCLUSIONS

High-quality, U.S.-registered, cataract trials enrolled acceptable proportions of women. However, the absolute number of female and racialized participants was low. Race and ethnicity were underreported. Disparity trends predominately held across secondary variables. To promote generalizability, future trials should pursue equitable demographic enrollment.

Prevalence of cataract and its contributing factors in Iranian elderly population: the Gilan eye study

PURPOSE

To report the prevalence and the associated factors leading to cataract among the Iranian population living in Gilan Province, Iran.

METHODS

This population-based cross-sectional study was performed from June to November 2014 on 2,975 residents aged ≥ 50 years old living in urban and rural regions of the Gilan Province in Iran. A representative sample of residents in the province was recruited into the study through door-to-door visiting, and baseline data were collected by questionnaire. All participants were referred to the medical center for comprehensive ophthalmic examination, laboratory tests, and blood pressure measurement.

RESULTS

Among the population, 2,588 (86.99%) subjects were eligible to be included in this study, categorized either into the cataract or the non-cataract group. The mean age of participants was 62.59 ± 8.92 years, and 57.5% were female. Higher prevalence of cataract was found in individuals of older ages (odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.10 to 1.16; P < 0.001) and a history of previous ocular surgery (OR = 5.78; 95% CI = 2.28 to 14.63; P < 0.001). At the same time, a lower prevalence of cataract was seen in patients exposed to sunlight for more than 4 h per day (OR = 0.49; 95% CI = 0.32 to 0.73; P = 0.001).

CONCLUSION

Cataract affects 50.50% of the study population, especially those over 80. The mildest form of cataract, grade zero, is the most common. Surgery for cataract has good outcomes. The risk of cataract is higher for those older or who have had eye surgeries. People not affected by cataract tend to be exposed to more sunlight.

National sex- and age-specific burden of blindness and vision impairment by cause in Mexico in 2019: a secondary analysis of the Global Burden of Disease Study 2019

Background

Reliable national estimations for blindness and vision impairment are fundamental to assessing their burden and developing public health policies. However, no comprehensive analysis is available for Mexico. Therefore, in this observational study we describe the national burden of blindness and vision loss by cause and severity during 2019.

Methods

Using public data from the Global Burden of Disease (GBD) study 2019, we present national prevalence and years lived with disability (YLDs) counts and crude and age-standardized rates (per 100,000 people) of total, severity- and cause-specific blindness and vision impairment with 95% uncertainty intervals (UIs) by sex and age group.

Findings

In Mexico, the burden of blindness and vision impairment was estimated at 11.01 million (95% UI, 9.25-13.11) prevalent cases and 384.96 thousand (259.57-544.24) YLDs during 2019. Uncorrected presbyopia caused the highest burden (6.06 million cases, 4.36-8.08), whereas severe vision loss and blindness affected 619.40 thousand (539.40-717.73) and 513.84 thousand (450.59-570.98) people, respectively. Near vision loss and refraction disorders caused 78.7% of the cases, whereas neonatal disorders and age-related macular degeneration were among the least frequent. Refraction disorders were the main cause of moderate and severe vision loss (61.44 and 35.43%), and cataracts were the second most frequent cause of blindness (26.73%). Females suffered an overall higher burden of blindness and vision impairment (54.99% and 52.85% of the total cases and YLDs), and people >50 years of age suffered the highest burden, with people between 70 and 74 years being the most affected.

Interpretation

Vision loss represents a public health problem in Mexico, with women and older people being the most affected. Although the causes of vision loss contribute differentially to the severity of visual impairment, most of the impairment is avoidable. Consequently, a concerted effort at different levels is needed to alleviate this burden.

Funding

This study received no funding.

The Global Burden of Glaucoma: Findings from the Global Burden of Disease 2019 Study and Predictions by Bayesian Age-Period-Cohort Analysis

This study aims to report the most up-to-date information about the global disease burden of glaucoma from 1990 to 2019 and to forecast trends in the next few years. Publicly available data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 were used in this study. The prevalence and disability-adjusted life years (DALYs) of glaucoma from 1990 to 2019 were reported. Finally, trends in the years following 2019 were predicted by Bayesian age-period-cohort (BAPC) models. We showed that, globally, the number of prevalent cases was 3,881,624 [95% uncertainty interval (UI): 3,301,963 to 4,535,045] in 1990 and increased to 7,473,400 (95% UI: 6,347,183 to 8,769,520) in 2019, while the age-standardized prevalence rate decreased from 111.92 [95% uncertainty interval (UI): 94.76 to 130.28 per 100,000] in 1990 to 94.68 (95% UI: 80.42 to 110.87 per 100,000) in 2019. The DALY number of glaucoma increased between 1990 and 2019, from 442,182 (95% UI: 301,827 to 626,486) in 1990 to 748,308 (95% UI: 515,636 to 1,044,667) in 2019. There was a significantly negative association between the sociodemographic index (SDI) and age-standardized DALY rates. The BAPC showed that the age-standardized DALY rate is predicted to decrease gradually in both males and females over the next few years. In summary, from 1990 to 2019, the global burden of glaucoma increased and the age-standardized DALY rate is predicted to decrease in the next few years. With the largest burden of glaucoma found in low-SDI regions, clinical diagnosis and treatment in such areas are more challenging and may warrant more attention.

Retrospective analysis of low vision assistive products – A 6-year review

PURPOSE

The purpose of the study was to analyze the demographics, visual acuity (VA), etiologies, recommended low vision assistive products (LVAP), and the acceptance rates of LVAP in various age groups.

METHODS

This was a long-term retrospective review of all the patients presenting to the low vision clinic of our tertiary eye care hospital from January 2011 to December 2016. Data obtained included age, gender, VA, visual fields, ocular pathology causing the low vision, and types of LVAP advised. The primary outcome was to analyze the type of LVAP prescribed in different age groups, and the secondary outcome was the acceptance rate of LVAP.

RESULTS

We analyzed the results of 8309 patients, out of which 2844 (34%. 2) were <15 years of age, 2425 (29.5%) were between 16-40 years, and 3013 (36.3%) were above 40 years. A total of 5522 (66.4%) had best-corrected visual acuity (BCVA) ranging from 6/18-3/60, and 2796 (33.6%) had BCVA from 3/60-No PL. Approximately 38% improved with LVAPs. The most common etiology was retinitis pigmentosa in 1545 (18.6%) patients, followed by congenital nystagmus in 1482 (17.8%), and the least was albinism 383 (4.6%). Maximum prescribed and accepted LVAP were hand and stand magnifiers among 1017 (44.3%) and 512 (52.6%) patients, respectively.

CONCLUSION

Products that are easy to use, require lesser adaptability, are cheap, and require lower maintenance have maximum acceptance rates. We suggest that great emphasis should be laid on training, education, and guidance for low vision rehabilitation centers.

Epidemiology, health policy and public health implications of visual impairment and age-related eye diseases in mainland China

The prevalence of visual impairment (VI) and age-related eye diseases has increased dramatically with the growing aging population in mainland China. However, there is limited comprehensive evidence on the progress of ophthalmic epidemiological research in mainland China to enhance our awareness of the prevention of eye diseases to inform public health policy. Here, we conducted a literature review of the population-based epidemiology of VI and age-related eye diseases in mainland China from the 1st of January 1946 to the 20th of October 2021. No language restrictions were applied. There was significant demographic and geographic variation in the epidemic of VI and age-related eye diseases. There are several factors known to be correlated to VI and age-related eye diseases, including age, gender, family history, lifestyle, biological factors, and environmental exposures; however, evidence relating to genetic predisposition remains unclear. In addition, posterior segment eye diseases, including age-related macular degeneration and diabetic retinopathy, are amongst the major causes of irreversible visual impairments in the senile Chinese population. There remains a significant prevention gap, with only a few individuals showing awareness and achieving optimal medical care with regards to age-related eye diseases. Multiple challenges and obstacles need to be overcome, including the accelerated aging of the Chinese population, the lack of structured care delivery in many underdeveloped regions, and unequal access to care. Despite the progress to date, there are few well-conducted multi-center population-based studies following a single protocol in mainland China, which findings can hopefully provide valuable cues for governmental decision-making and assist in addressing and halting the incidence of VI and age-related eye diseases in China.

Governmental support for achieving "VISION 2020: the Right to Sight" in Iran: the cataract surgical rates

PURPOSE

The aim of this study was evaluate the effect of governmental support in the form of Health Transformation Plan (HTP) on increasing the cataract surgical rate.

METHODS

The number of cataract surgeries was collected from Iranian cataract surgery clinics during 2019. HTP was implemented in 2014. Forty-seven major and forty-five minor surgery centers were selected from all provinces. In each center, sampling was done from 2012, 2013, 2015, and 2016.

RESULTS

On average, 6202 and 7134 cataract surgery rate were performed before and after HTP, respectively. The cataract surgical rate rose by 15.03% after the HTP. After HTP, the proportion of cataract surgery increased by 21.32% in governmental centers and decreased by 17.56%, 24.45%, and 14.89% in private, insurance, and charity centers, respectively. The cataract surgical rate was 4093 and 6026 in the first economic quartile (the poorest), 3669 and 4595 in the second quartile, 5884 and 5928 in the third quartile, and 8427 and 9681 in the fourth quartile (the richest) before and after HTP, respectively. The highest growth in the cataract surgical rate was seen in the first quartile (47.24%) followed by the second (25.26%), fourth (14.88%), and third quartiles (0.74%).

CONCLUSION

The Health Transformation Plan has been successful in increasing the cataract surgical rate in the low-income group and identifying differences in the services as well as the economic groups within the population.

Reasons for delay in cataract surgery in patients with advanced cataracts during the COVID-19 pandemic

Purpose:

To analyze the reasons for delay in cataract surgery in patients with advanced cataracts during the COVID-19 pandemic.

Methods:

This was a prospective, cross-sectional, multicenter questionnaire study which included patients with mature cataract, nuclear sclerotic cataract grade IV, and cataracts with best corrected visual acuity (BCVA) <5/60, during the COVID-19 pandemic from December 2020 to April 2021. Reasons for delay in presentation to the hospital were analyzed.

Results:

One thousand four hundred seventy two patients were recruited with advanced cataracts. Absence of ophthalmic care nearby (44.2%), lack of awareness regarding elective surgeries (42.6%), lack of public transportation (37%), fear of contracting COVID-19 (23.4%), and waiting for outreach camps (20.4%) were found to be the reasons behind the delay in cataract surgery. 53.7% of the patients had worsening of defective vision and 55.3% of them had difficulty in carrying out activities of family living. 30.8% of the patients faced difficulty in commuting and 8.4% of the patients suffered a fall during this pandemic due to worsening of the visual acuity.

Conclusion:

The lockdown imposed during the pandemic has created a significant backlog of patients who are progressing to advanced cataracts due to lack of ophthalmic care nearby, lack of awareness regarding elective surgeries, lack of public transportation, and no outreach camps. Proactive measures to deal with this backlog are of utmost need to prevent blindness due to cataract.

Prevalence of Visual Impairment Among Students Before and During the COVID-19 Pandemic, Findings From 1,057,061 Individuals in Guangzhou, Southern China

BACKGROUND

Visual impairment (VI) is a growing public health concern among students as a result of the COVID-19 pandemic.

OBJECTIVE

This study investigated the change in VI before and during the pandemic among students.

METHODS

Data on 547,864 and 497,371 students were obtained from the Guangzhou Survey on Students' Constitution and Health (GSSCH) collected in October 2019 and October 2020, respectively. VI was defined as the unaided distance visual acuity lower than 20/25 Snellen equivalent (LogMAR 0.10) in the worse eye. Change in VI based on age and sociodemographic variables were evaluated by chi-square test for trend as appropriate. Comparisons of different categorical variables were tested by contingency tables-based chi-square test. We have further analysis of the students who went through both of the 2019 and 2020 examinations for evaluating the VI incidence during the COVID-19 pandemic.

RESULTS

More than 1,045,235 students were involved in our study, among whom 271,790 (54.65%) out of 497,371 students in Guangzhou suffered from VI during the COVID-19 compared with 293,001(53.48%) visually impaired students (total tested participants = 547,864) before the COVID-19 pandemic. During the pandemic, the overall prevalence of VI actually showed an increased age tendency and reached the highest level in the 17 [80.04%, 95%Confidence interval (CI):79.53 to 80.54%] and the 18 (79.64, 95%CI: 79.06 to 80.23%) age groups. Rapid growth was detected among students aged between 9 and 16 years old (raised by 46.21) while older students were more likely to get moderate and severe VI than younger ones. Students involved in more screen-based activities [(64.83%, 2019); (66.59%, 2020)] appeared to have a higher prevalence of VI than those involved in less [(49.17%, 2019); (49.26%, 2020)].

CONCLUSION

A rising trend of VI among students was detected before and during the COVID-19 pandemic. Moreover, the pandemic appeared to be associated with a rapid VI shift in younger and boy populations. Potential danger may arise when public health emergencies occur in the school, and more effort should be made to improve students' vision.

Challenges in Eye Care in the Asia-Pacific Region

The Asia-Pacific region is home to a 4.3-billion population and one of the most rapidly aging regions. Addressing the eye care needs in the region would greatly boost the progress toward achieving universal eye health. Over 20 countries/regions have actively engaged in the "VISION 2020" initiative launched since 1999, and remarkable achievements have been witnessed as demonstrated by an increase in both the number and density of ophthalmologists in almost all countries. Nevertheless, formidable and emerging challenges are to be overcome in the coming century. From 1990 to 2015, the absolute number of blind people increased by 17.9%, largely due to population growth and aging. The Asia-Pacific region, the most populous continent with a rapidly aging population, would inevitably be left to tackle this challenge. Furthermore, a high prevalence of blinding eye diseases imposes great pressure on current eye care services, with South Asia having the highest age-standardized prevalence of moderate to severe visual impairment (17.5%) and mild vision impairment (12.2%) globally, and high-income countries having the highest overall prevalence of myopia, reaching 53.4% with East Asia having the second-highest overall prevalence (51.6%). Moreover, the availability of ophthalmic resources varies greatly in the region, with the density of ophthalmologists ranging from over 114 ophthalmologists per million population in Japan to 0 in Micronesia, and a highly disproportionate urban-rural distribution. This article aims to shed light on challenges faced by the Asia-Pacific ophthalmic community and propose corresponding strategies to tackle those challenges.

Distribution and determinants of hospital efficiency and relative productivity in county-level hospitals in rural China: an observational study

BACKGROUND

Cataract surgery is very important to prevent blindness, but its productivity and efficiency in China are unknown. Our study aimed to evaluate the geographical distribution of cataract surgeons and prospectively identify the factors associated with the increased productivity in cataract surgery and efficiency in outpatient ophthalmic services in rural Chinese hospitals.

METHODS

Data were prospectively collated from various hospital datasets and the census registered by the geographical unit county. Prior to mapping, the geographical location data of counties were cross-linked with the equivalent ophthalmologist and service output data to create categories and map multiple data attributes. Descriptive statistical analyses were performed to characterise the data stratified by county. Linear regression analyses were used to explore the factors associated with the increased productivity/efficiency.

RESULTS

The ophthalmologists, surgical productivity of ophthalmologists and outpatient efficacy of ophthalmologists significantly varied across counties. During the period between 2016 and 2018, the median (IQR) change in surgical productivity of and outpatient efficacy of ophthalmologists were 31.627 (-3.33 to 29.94) and 118.08 (-132.30 to 740.89). In the simple regression analysis for predictors of a high productivity change, only the increased number of phaco machine had statistical significance (p=0.003). In addition, only the gross domestic product per capita in 2016 was associated with an increased improvement in efficiency of outpatient services (p=0.008).

CONCLUSIONS

This study demonstrated that the ophthalmologist productivity and the efficiency of outpatient services were unequally geographically distributed, and their predictors were identified. Further studies to elucidate the extent of the problem and improve the health service delivery models are required.

Visual Impairment Prevalence, Causes, and Role of Healthcare Access: A Systematic Review and Meta-Analysis in Iran

Purpose

Healthcare access is one of the determinants of visual impairment (VI), as a public health problem. The objective of this study was to estimate VI prevalence, related causes, and its correlation with access to physicians in Iran.

Methods

: This systematic review and meta-analysis include observational studies published in Iran. PubMed, Web of Science, Scopus, Google Scholar, and local databases were systematically searched by using the MeSH headings. Data on the provincial distribution of physicians, as an index of access to healthcare, was retrieved. A random-effect meta-analysis was performed to assess.

Results

Eight articles were included. The pooled prevalence of blindness, low vision, and VI was 0.80% (95% CI: 0.61–0.99%), 2.92% (95% CI: 2.40–3.44%), and 5.57% (95% CI: 4.71–6.43%). Refractive errors were the most common causes of VI based on PVA with the pooled prevalence of 54.6% (95% CI: 43.4–65.8%). Based on BCVA, we found that the pooled prevalence of cataracts was 37.4% (95% CI: 29.5–45.3%) as the most common cause of VI. The results of metaregression showed that the greater number of general practitioners (GPs) (P value = 0.01) and pharmacists (P value = 0.024) per population were associated with a lower prevalence of blindness.

Conclusion

Some of the main causes of visual impairment in Iran are preventable. Access to healthcare services may lead to early diagnosis of preventable causes of VI. Further well-designed studies and national surveys should be conducted to provide accurate data from different regions of Iran.

Prevalence and causes of vision loss in China from 1990 to 2019: findings from the Global Burden of Disease Study 2019

BACKGROUND

Vision loss is an important public health issue in China, but a detailed understanding of national and regional trends in its prevalence and causes, which could inform health policy, has not been available. This study aimed to assess the prevalence, causes, and regional distribution of vision impairment and blindness in China in 1990 and 2019.

METHODS

Data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 were used to estimate the prevalence of moderate and severe vision impairment and blindness in China and compare with other Group of 20 (G20) countries. We used GBD methodology to systematically analyse all available demographic and epidemiological data at the provincial level in China. We compared the age-standardised prevalences across provinces, and the changes in proportion of vision loss attributable to various eye diseases in 1990 and 2019. We used two different counterfactual scenarios with respect to population structure and age-specific prevalence to assess the contribution of population growth and ageing to trends in vision loss.

FINDINGS

In 2019, the age-standardised prevalence was 2·57% (uncertainty interval [UI] 2·28-2·86) for moderate vision impairment, 0·25% (0·22-0·29) for severe vision impairment, and 0·48% (0·43-0·54) for blindness in China, which were all below the global average, but the prevalence of moderate and severe vision impairment had increased more rapidly than in other G20 countries from 1990 to 2019. The prevalence of vision loss increased with age, and the main causes of vision loss varied across age groups. The leading causes of vision impairment in China were uncorrected refractive error, cataract, and macular degeneration in both 1990 and 2019 in the overall population. From 1990 to 2019, the number of people with moderate vision impairment increased by 133·67% (from 19·65 to 45·92 million), those with severe vision impairment increased by 147·14% (from 1·89 to 4·67 million), and those with blindness increased by 64·35% (from 5·29 to 8·69 million); in each case, 20·16% of the increase could be explained by population growth. The contributions to these changes by population ageing were 87·22% for moderate vision impairment, 116·06% for severe vision impairment, and 99·22% for blindness, and the contributions by age-specific prevalence were 26·29% for moderate vision impairment, 10·91% for severe vision impairment, and -55·04% for blindness. The prevalence and specific causes of vision loss differed across provinces.

INTERPRETATION

Although a comprehensive national policy to prevent blindness is in place, public awareness of visual health needs improving, and reducing the prevalence of moderate and severe vision impairment should be prioritised in future work.

FUNDING

China National Key Research and Development Programme and Beijing Municipal Special Funds for Medical Research on Public Welfare Development and Reform.

Prevalence and causes of visual impairment among older persons living in low-income old age homes in Durban, South Africa

BACKGROUND

Visual impairment (VI) increases with age and has been reported to be more prevalent among older adults living in old age homes than in the general population.

AIM

To determine the prevalence and causes of VI among older adults living in low-income old age homes in Durban, South Africa.

SETTING

This study was conducted at low-income old age homes in Durban.

METHODS

This cross-sectional study of 118 residents aged 60 years and older, collected socio-demographic data, presenting visual acuities (VAs) for each eye, and binocularly. Anterior segment eye examinations were conducted with a penlight torch and a portable slit-lamp, while posterior segment evaluation was conducted with direct and indirect ophthalmoscopy. Objective and subjective refractions were performed, and the best-corrected distance and near VAs were measured in each eye. VI was defined as presenting VA 6/18 and included moderate VI ( 6/18-6/60), severe VI ( 6/60 -3/60) and blindness ( 6/120).

RESULTS

The mean age of the participants was 73.3 years and included 80.5% females and 19.5% males. The prevalence of VI and blindness was 63.6%. Optical correction significantly reduced the prevalence of VI and blindness by 19.5% (p 0.05). The main causes of non-refractive VI and blindness were cataract (54.5%), posterior segment disorders (25.5%) and corneal opacities (20%).

CONCLUSION

The prevalence of VI and blindness is high among residents in low-income old age homes living in Durban. Refractive correction and surgical cataract intervention can significantly reduce the burden of VI and blindness among the elderly residents.

Cataract blindness in Hungary

AIM

To estimate the prevalence of blindness and visual impairment resulting from cataract in the population aged ≥50y in Hungary, and to assess the cataract surgical services.

METHODS

A rapid assessment of avoidable blindness (RAAB) was conducted. A total of 3523 eligible people were randomly selected and examined. Each participant underwent surgery for cataract was interviewed with regard to the year, place, and costs of the surgery. Participants with obvious cataract were asked why they had not yet undergone surgery (barriers to surgery).

RESULTS

An estimated 12 514 people were bilaterally blind; the visual acuity (VA) in 19 293 people was <6/60, and the VA in 73 962 people was <6/18 in the better eye due to cataract. An estimated 77 933 eyes are blind; 98 067 eyes had a VA of <6/60, and an estimated 277 493 eyes had a VA of <6/18 due to cataract. Almost all cataract surgeries were conducted in government hospitals. The age- and sex-adjusted cataract surgical coverage with VA<3/60 in eyes was 90.0%. The rate of good visual outcome after surgery was 79.5%. Ocular comorbidity was the main cause of poor outcome (78.1%), followed by late complications (such as posterior capsule opacification) (17.2%), inadequate optical correction (3.1%), and surgical complications (1.6%). The main barrier to surgery in people with bilateral cataract and VA of <6/60 was 'need not felt'.

CONCLUSION

The prevalence of visual impairment resulting from cataract is slightly higher than expected. The quality of the cataract surgical service seems adequate in Hungary. However, the number of cataract operations per year should continue to increase due to the increasing patient demands and the aging population.

Prevalence and causes of vision loss in East Asia in 2015: magnitude, temporal trends and projections

BACKGROUND

To determine the prevalence and causes of blindness and vision impairment (VI) in East Asia in 2015 and to forecast the trend to 2020.

METHODS

Through a systematic literature review and meta-analysis, we estimated prevalence of blindness (presenting visual acuity <3/60 in the better eye), moderate-to-severe vision impairment (MSVI; 3/60≤presenting visual acuity <6/18), mild vision impairment (mild VI: 6/18≤presenting visual acuity <6/12) and uncorrected presbyopia for 1990, 2010, 2015 and 2020. A total of 44 population-based studies were included.

RESULTS

In 2015, age-standardised prevalence of blindness, MSVI, mild VI and uncorrected presbyopia was 0.37% (80% uncertainty interval (UI) 0.12%-0.68%), 3.06% (80% UI 1.35%-5.16%) and 2.65% (80% UI 0.92%-4.91%), 32.91% (80% UI 18.72%-48.47%), respectively, in East Asia. Cataract was the leading cause of blindness (43.6%), followed by uncorrected refractive error (12.9%), glaucoma, age-related macular degeneration, corneal diseases, trachoma and diabetic retinopathy (DR). The leading cause for MSVI was uncorrected refractive error, followed by cataract, age-related macular degeneration, glaucoma, corneal disease, trachoma and DR. The burden of VI due to uncorrected refractive error, cataracts, glaucoma and DR has continued to rise over the decades reported.

CONCLUSIONS

Addressing the public healthcare barriers for cataract and uncorrected refractive error can help eliminate almost 57% of all blindness cases in this region. Therefore, public healthcare efforts should be focused on effective screening and effective patient education, with access to high-quality healthcare.

Peek Community Eye Health - mHealth system to increase access and efficiency of eye health services in Trans Nzoia County, Kenya: study protocol for a cluster randomised controlled trial

BACKGROUND

Globally, eye care provision is currently insufficient to meet the requirement for eye care services. Lack of access and awareness are key barriers to specialist services; in addition, specialist services are over-utilised by people with conditions that could be managed in the community or primary care. In combination, these lead to a large unmet need for eye health provision. We have developed a validated smartphone-based screening algorithm (Peek Community Screening App). The application (App) is part of the Peek Community Eye Health system (Peek CEH) that enables Community Volunteers (CV) to make referral decisions about patients with eye problems. It generates referrals, automated short messages service (SMS) notifications to patients or guardians and has a program dashboard for visualising service delivery. We hypothesise that a greater proportion of people with eye problems will be identified using the Peek CEH system and that there will be increased uptake of referrals, compared to those identified and referred using the current community screening approaches.

STUDY DESIGN

A single masked, cluster randomised controlled trial design will be used. The unit of randomisation will be the 'community unit', defined as a dispensary or health centre with its catchment population. The community units will be allocated to receive either the intervention (Peek CEH system) or the current care (periodic health centre-based outreach clinics with onward referral for further treatment). In both arms, a triage clinic will be held at the link health facility four weeks from sensitisation, where attendance will be ascertained. During triage, participants will be assessed and treated and, if necessary, referred onwards to Kitale Eye Unit.

DISCUSSION

We aim to evaluate a M-health system (Peek CEH) geared towards reducing avoidable blindness through early identification and improved adherence to referral for those with eye problems and reducing demand at secondary care for conditions that can be managed effectively at primary care level.

TRIAL REGISTRATION

The Pan African Clinical Trials Registry (PACTR), 201807329096632 . Registered on 8 June 2018.

Barriers in utilisation of low vision assistive products

AIM

To understand the barriers in utilisation of low vision assistive products (LVAPs) from the perspective of patients with low vision.

METHODS

Patients referred to low vision clinic in a tertiary eye care hospital in India who were prescribed LVAPs but were un-willing to accept the products were interviewed using questionnaires. Data pertaining to the age, diagnosis, gender, occupation, preferred LVAPs, patient's perception of vision loss and the primary reason for non-acceptance of LVAPs were analysed.

RESULTS

A total of 235 among the 413 patients who noticed improvement in visual performance with LVAPs were unwilling to utilise these products. The questionnaire revealed that 53% of the patients who felt they were not candidates for LVAPs were experiencing severe visual impairment (p < 0.02). Non-acceptance was highest (68.6%) in patients < 15 years of age. The most common causes of non-acceptance were social stigma in patients < 40 years (41.3%; p < 0.0001), fear of loss of employment in patients 41-60 years (26.6%; p < 0.01) and low necessity in patients > 60 years (25%; p < 0.001). Denial of the magnitude of their illness was more common in patients above 60 years (16.5%). Non-acceptance rate was lowest for macular disorders (39.6%) and highest for retinitis pigmentosa (81%). Among devices, hand and stand magnifiers had the lowest non-acceptance rate (41%). Telescopes and electronic devices had the highest rate of non-acceptance (92% and 89%, respectively).

CONCLUSION

Reasons for poor utilisation of LVAPs are multifactorial extending beyond affordability or accessibility. Knowledge of these barriers can help in creating content for awareness campaigns among patients, healthcare professionals and general society. Further research is necessary on the psychological and psycho social contributors to this process.

Evaluation of the safety and quality of day-case cataract surgery based on 4151 cases

AIM

To evaluate the safety, quality and prospects of day-case cataract surgery performed in a Jiangsu public tertiary hospital.

METHODS

The general and clinical data for patients who underwent day-case cataract surgery between August 1, 2014 and December 31, 2016 at this hospital were collected. The incidences of intraoperative and postoperative complications, preoperative and postoperative best-corrected visual acuities (BCVAs), delayed discharge rate, rate of unplanned re-admission to hospital, and patient satisfaction were analyzed.

RESULTS

A total of 4151 patients received cataract phacoemulsification surgery to correct age-related, congenital, traumatic, or complicated cataracts. Of these, age-related cataracts were the most frequently occurring. Patient age ranged from 18 to 101y and the vast majority of patients were between 60 and 80 years old. Of the 4151 patients, 64.73% (2687/4151) had a systemic disease. The number of patients increased over the years, with the average number of patients per month being 90.4, 124.83, and 183.42 in 2014, 2015 and 2016, respectively. The average preoperative BCVA was 0.102±0.057 and average postoperative BCVAs at 1d, 1wk, and 1mo post-surgery were 0.453±0.264, 0.657±0.285, and 0.734±0.244, respectively. For intraoperative complications, 4.12% (171/4151) had posterior capsule rupture, 0.79% (33/4151) had iris or ciliary body injury, and 0.048% (2/4151) had suprachoroidal hemorrhage. For postoperative complications, 4.38% (182/4151) had cornea edema, 7.78% (323/4151) had intraocular hypertension, 0.096% (4/4151) had IOL toxicity syndrome, 0.28% (12/4151) had retained lens cortex, and 0.048% (2/4151) had hyphema. The delayed discharge rate was 0.82% (44/4151) and the unplanned re-admission to the hospital was 0 (0/4151). The patient satisfaction rate was 91.42% (3795/4151).

CONCLUSION

Day-case cataract surgery is safe and effective with good prospects for development.

Effect of Community Screening on the Demographic Makeup and Clinical Severity of Glaucoma Patients Receiving Care in Urban China

PURPOSE

To assess differences in clinical and demographic characteristics between glaucoma patients identified by community screening and those newly diagnosed in hospital in a Chinese setting.

DESIGN

Prospective comparative cohort study.

METHODS

A total of 373 patients identified with glaucoma among 27 000 persons undergoing community screening were enrolled as the Screening group. The Clinic group consisted of 119 consecutively presenting, newly diagnosed glaucoma patients in hospital. Primary outcomes were mean deviation (MD), visual field index (VFI) and pattern standard deviation (PSD) on Humphrey Field Analyzer, and intraocular pressure (IOP). Disease severity was categorized into 5 stages based on MD.

RESULTS

A total of 89.6% (328/373) of Screening group patients had IOP < 21 mm Hg, compared to 48.7% (58/119) in the Clinic group (P < .001). The mean VFI, MD, and PSD were 76.4% ± 23.8%, -9.7 ± 7.3 dB, and 6.4 ± 3.4 dB in the Screening group and significantly worse in the Clinic group: 44.1% ± 32.0%, -19.8 ± 9.5 dB, and 7.6 ± 3.1 dB (P < .001 for MD and VFI, P = .001 for PSD). Nearly three quarters of Screening patients had early or moderate visual field loss (monocular), while nearly half of Clinic patients had severe loss at the time of diagnosis. Screening patients were significantly more likely to be older (P < .001) and female (P < .001) than Clinic patients.

CONCLUSION

Glaucoma patients detected through community screening had significantly milder damage, and were more likely to include underserved groups (women, elderly) than those newly diagnosed in a clinic in this setting. Comparison with population studies suggests that cases of glaucoma with IOP < 21 mm Hg are severely underascertained in China, a situation that may be improved by screening.

Vision-specific and psychosocial impacts of low vision among patients with low vision at the eastern regional Low Vision Centre

Purpose: To determine vision-specific and psychosocial implications of low vision among patients with low vision visiting the Low Vision Centre of the Eastern Regional Hospital in Ghana.Methodology: This was a descriptive case-control study of 41 patients with low vision and 41 patients with normal vision recruited from the Low Vision Centre of the Eastern Regional Hospital by simple random sampling. Data on vision-specific and psychosocial impacts of low vision was collected using the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). Biographical and clinical characteristics such as age, gender, educational status, marital status, employment and income status were gathered from consenting patients. Mann–Whitney U analysis using Statistical Package for Social Scientists (SPSS) was conducted to compare scores on vision-specific and psychosocial subscales of the NEI VFQ-25 between patients with low vision and patients with normal vision.Results: Patients with low vision recorded the lowest score on the driving subscale (median = 8.33, IQR [interquartile range]: 8.33–41.67, n = 41, p < 0.001), as well as on distance activities (median = 35.42, IQR = 16.70–58.80). Psychosocial implications of low vision included high dependency (median = 33.33, IQR = 25.00–50.00), reduced mental health (median = 37.50, IQR = 25.00–50.00) and limitation in partaking in social activities (median = 50.00, IQR = 37.50–78.00).Conclusion: Low vision has both vision-specific and psychosocial implications for the patients. Low vision management and services should therefore be tailored to meet these psychosocial and vision-specific needs to enable patients better accept their visual changes and to be better prepared to use their remaining vision to achieve their daily goals.

Evaluation of day care versus inpatient cataract surgery performed at a Jiangsu public Tertiary A hospital

BACKGROUND

High cataract incidence and low cataract surgical rate are serious public health problems in China, despite the fact that efficient day care cataract surgery has been implemented in some public Tertiary A hospitals in China. In this study, we compared not only clinical outcomes, hospitalization time and total costs but also payment manners between day care and inpatient procedures for cataract surgery in a Jiangsu public Tertiary A hospital to put forward several instructional suggestions for the improvement of government medical policies.

METHODS

In total, 4151 day care cases and 2509 inpatient cases underwent the same cataract surgery in the day care ward and ordinary ward respectively, and were defined as two groups. General information, complications, postoperative best corrected visual acuity (BCVA), hospitalization time, total costs and especially payment method were analyzed to compare day care versus inpatient.

RESULTS

The general data display no significant differences (P > 0.05), and no significant difference between complications and postoperative BCVA were observed between the two groups (P > 0.05). The period of stay in hospital was significantly different (P < 0.001). The total costs were lower for day care than for inpatients (P < 0.001). To avoid sampling error, we analyzed the data of payment manner for each patient among this period. Day care patients tended to pay for the procedure using the Urban Employees Basic Medical Insurance (UEBMI) method, while inpatients tended to use the Out-of-Pocket Medical Treatment (OMT) payment method (P < 0.001).

CONCLUSION

Day surgery of cataract is more cost-effective and efficient than inpatient surgery with equivalent clinical outcomes. As an efficient therapeutic regimen, day care surgery should be further promoted and supported by the government policies.

Impact of virtual reality simulation on learning barriers of phacoemulsification perceived by residents

Objective

To identify residents’ perceived barriers to learning phacoemulsification surgical procedures and to evaluate whether virtual reality simulation training changed these perceptions.

Design

The ophthalmology residents undertook a simulation phacoemulsification course and proficiency assessment on the Eyesi system using the previously validated training modules of intracapsular navigation, anti-tremor, capsulorrhexis, and cracking/chopping. A cross-sectional, multicenter survey on the perceived difficulties in performing phacoemulsification tasks on patients, based on the validated International Council of Ophthalmology’s Ophthalmology Surgical Competency Assessment Rubric (ICO-OSCAR), using a 5-point Likert scale (1 = least and 5 = most difficulty), was conducted among residents with or without prior simulation training. Mann–Whitney U tests were carried out to compare the mean scores, and multivariate regression analyses were performed to evaluate the association of lower scores with the following potential predictors: 1) higher level trainee, 2) can complete phacoemulsification most of the time (>90%) without supervisor’s intervention, and 3) prior simulation training.

Setting

The study was conducted in ophthalmology residency training programs in five regional hospitals in Hong Kong.

Results

Of the 22 residents, 19 responded (86.3%), of which 13 (68.4%) had completed simulation training. Nucleus cracking/chopping was ranked highest in difficulty by all respondents followed by capsulorrhexis completion and nucleus rotation/manipulation. Respondents with prior simulation training had significantly lower difficulty scores on these three tasks (nucleus cracking/chopping 3.85 vs 4.75, P = 0.03; capsulorrhexis completion 3.31 vs 4.40, P = 0.02; and nucleus rotation/manipulation 3.00 vs 4.75, P = 0.01). In multivariate analyses, simulation training was significantly associated with lower difficulty scores on these three tasks.

Conclusion

Residents who had completed Eyesi simulation training had higher confidence in performing the most difficult tasks perceived during phacoemulsification.

Inferior Decentration of Multifocal Intraocular Lenses in Myopic Eyes

PURPOSE

To investigate the tilt and decentration of multifocal intraocular lenses (MfIOLs) implanted in myopic eyes.

DESIGN

A prospective cohort study.

METHODS

Twenty-eight myopic eyes and 56 emmetropic eyes were evaluated. Phacoemulsification with Tecnis ZMB00 MfIOL (Abbott Medical Optics, Santa Ana, California, USA) implantation was performed. At 1 year post-surgery, routine postoperative examinations were performed, and tilt and decentration of the MfIOLs, high-order aberrations, and modulation transfer function (MTF) were evaluated using the OPD-Scan III aberrometer (Nidek Co, Ltd, Gamagori, Japan). Subjective symptoms were assessed with a Quality of Vision questionnaire.

RESULTS

Postoperative uncorrected distance visual acuity (VA), best-corrected distance VA, and uncorrected near VA did not differ between the 2 groups. The mean IOL tilt and horizontal decentration were not different between the control and myopic groups. However, the myopic group presented significantly inferior decentration in the capsular bag compared with the control group (-0.03 ± 0.22 mm vs -0.21 ± 0.29 mm, P = .002). The overall decentration values were 0.32 ± 0.14 mm in the controls and 0.40 ± 0.18 mm in the myopic group (P = .023). Axial length was negatively correlated with vertical decentration (r = -0.268, P = 0.014) and positively correlated with overall decentration (r = 0.334, P = .002). Worse aberration data, poorer MTF, and more subjective symptoms were also found in the myopic group than in the controls.

CONCLUSION

Greater inferior decentration of MfIOLs and a consequent decrease in visual quality were found in myopic eyes, indicating that the increasing incompatibility between IOL and capsular bag size with axial length elongation should not be underestimated.

The burden of ocular diseases in an underdeveloped village in Southwest Sumba, Eastern Indonesia, 2016

Background: Prevalence estimates of ocular diseases in a given district are important to plan the programs of eye care services. This study aimed to describe the burden of ocular diseases as an initial step in improving eye care services in underdeveloped areas in Indonesia.Methods: A cross-sectional study was performed among residents of Perobatang Village in Southwest Sumba district in July 2016. Eye examinations were conducted by ophthalmologists, and visual acuity was measured by optometrists. Participants were provided with appropriate treatment according to diagnosis. Surgical services were offered two months after the examination.Results: After eximining a total of 667 of 1,459 (46%) residents, the result showed that the most frequent ocular problems were presbyopia (30.8%), cataract (12.8%), refractive error (11.3%), and pterygium (10.7%). The proportion of myopia was 5.9%, hyperopia was 5.0%, and astigmatism was 2.2%. Moreover, the proportion of blindness was 10%. Cataract caused blindness in 44 participants. Other causes of blindness included age-related macular degeneration, retinopathy, optic atrophy, glaucoma, retinal detachment and trauma.Conclusion: The burden of ocular problems in Perobatang Village, Southwest Sumba, Eastern Indonesia was high. These findings showed the importance of public health action from local government and non-governmental organizations to improve eye care services in Southwest Sumba district.

Updates on the Epidemiology of Age-Related Macular Degeneration

This meta-analysis reports on current estimates of the prevalence of age-related macular degeneration (AMD) based on a review of recent meta-analyses and literature research. Within an age of 45-85 years, global prevalences of any AMD, early AMD, and late AMD were 8.7% [95% credible interval (CrI), 4.3‒17.4], 8.0% (95% CrI, 4.0‒15.5), and 0.4% (95% CrI, 0.2-0.8). Early AMD was more common in individuals of European ancestry (11.2%) than in Asians (6.8%), whereas prevalence of late AMD did not differ significantly. AMD of any type was less common in individuals of African ancestry. The number of individuals with AMD was estimated to be 196 million (95% CrI, 140‒261) in 2020 and 288 million (95% CrI, 205‒399) in 2040. The worldwide number of persons blind (presenting visual acuity < 3/60) or with moderate to severe vision impairment (MSVI; presenting visual acuity < 6/18 to 3/60 inclusive) due to macular disease in 2010 was 2.1 million [95% uncertainty interval (UI), 1.9‒2.7] individuals out of 32.4 million individuals blind and 6.0 million (95% UI, 5.2‒8.1) persons out of 191 million people with MSVI. Age-standardized prevalence of macular diseases as cause of blindness in adults aged 50+ years worldwide decreased from 0.2% (95% UI, 0.2‒0.2) in 1990 to 0.1% (95% UI, 0.1‒0.2) in 2010; as cause for MSVI, it remained mostly unchanged (1990: 0.4%; 95% UI, 0.3‒0.5; 2010: 0.4%; 95% UI, 0.4‒0.6), with no significant sex difference. In 2015, AMD was the fourth most common cause of blindness globally (in approximately 5.8% of blind individuals) and third most common cause for MSVI (3.9%). These data show the globally increasing importance of AMD.

Burden of vision loss associated with eye disease in China 19902020: findings from the Global Burden of Disease Study 2015

AIMS

To assess the burden of vision loss due to eye disease in China between 1990 and 2015, and to predict the burden in 2020.

METHODS

Data from the GBD 2015 (Global Burden of Diseases, Injuries, and Risk Factors Study 2015) were used. The main outcome measures were prevalence and years lived with disability (YLDs) for vision loss due to cataract, glaucoma, macular degeneration, other vision loss, refraction and accommodation disorders and trachoma.

RESULTS

Prevalence for eye diseases increased steadily from 1990 to 2015, and will increase until 2020. From 1990 to 2015, the most common eye disorder was refraction and accommodation disorders. From 1990 to 2015, the vision loss burden due to eye disease decreased for those aged 0-14 years, and increased for those aged 15 years and above, with the most notable increases occurring among those aged 50 years and above. China ranked 10th when comparing YLDs for vision loss due to eye disease with the other members of the G20 (Group of Twenty, an international forum for the governments from 20 major economies) . Age-standardised YLD rates for vision loss due to eye disease declined in all 19 countries, except for China. The burden from vision loss due to eye disease ranked 12th and 11th among all causes of health loss in China in 1990 and 2015, respectively.

CONCLUSION

Alone among major economies, China has experienced an increase in the burden of age-standardised vision loss from eye disease over the last two decades. In the future, China may expect a growing burden of vision loss due to population growth and ageing.

Associations of PARP-1 variant rs1136410 with PARP activities, oxidative DNA damage, and the risk of age-related cataract in a Chinese Han population: A two-stage case-control analysis

OBJECTIVE

To investigate whether a single nucleotide polymorphism (SNP) rs1136410 in the poly (ADP-ribose) polymerase-1 (PARP-1) gene was associated with PARP activities, 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, and the risk of age-related cataract (ARC) in a Chinese Han population.

METHODS

In this two-stage case-control study with a total of 1010 ARC patients and 1045 controls, SNP rs1136410 was genotyped by high-resolution melting analyses (HRM). PARP activities and 8-OHdG levels in peripheral blood mononuclear cells (PBMCs) were determined by ELISA kits.

RESULTS

In discovery, replication, and their merged sets, the variant genotypes (AG+GG) of SNP rs1136410 were significantly associated with an increased risk of ARC under a dominant model (Adjusted odds ratio (OR)=1.42, P_adj=0.001 for the merged set). This association was further identified in subtype analyses for cortical ARC (Adjusted OR=1.69, P_adj<0.001). In subgroup analyses, we identified a significant interaction between SNP rs1136410 and smoking habit in increasing ARC risk (P_inter=0.019). Moreover, ARC patients had lower activities of PARP and higher levels of 8-OHdG than controls. There were significant correlations of SNP rs1136410 with decreased PARP activities and increased 8-OHdG levels in controls and patients with cortical ARC.

CONCLUSIONS

This study suggests that SNP rs1136410 may confer susceptibility to ARC by affecting PARP activities and oxidative DNA damage.

Number of People Blind or Visually Impaired by Glaucoma Worldwide and in World Regions 1990 - 2010: A Meta-Analysis

Objective

To assess the number of individuals visually impaired or blind due to glaucoma and to examine regional differences and temporal changes in this parameter for the period from 1990 to 2012.

Methods

As part of the Global Burden of Diseases (GBD) Study 2010, we performed a systematic literature review for the period from 1980 to 2012. We primarily identified 14,908 relevant manuscripts, out of which 243 high-quality, population-based studies remained after review by an expert panel that involved application of selection criteria that dwelt on population representativeness and clarity of visual acuity methods used. Sixty-six specified the proportion attributable to glaucoma. The software tool DisMod-MR (Disease Modeling–Metaregression) of the GBD was used to calculate fraction of vision impairment due to glaucoma.

Results

In 2010, 2.1 million (95% Uncertainty Interval (UI):1.9,2.6) people were blind, and 4.2 (95% UI:3.7,5.8) million were visually impaired due to glaucoma. Glaucoma caused worldwide 6.6% (95% UI:5.9,7.9) of all blindness in 2010 and 2.2% (95% UI:2.0,2.8) of all moderate and severe visual impairment (MSVI). These figures were lower in regions with younger populations (<5% in South Asia) than in high-income regions with relatively old populations (>10%). From 1990 to 2010, the number of blind or visually impaired due to glaucoma increased by 0.8 million (95%UI:0.7, 1.1) or 62% and by 2.3 million (95%UI:2.1,3.5) or 83%, respectively. Percentage of global blindness caused by glaucoma increased between 1990 and 2010 from 4.4% (4.0,5.1) to 6.6%. Age-standardized prevalence of glaucoma related blindness and MSVI did not differ markedly between world regions nor between women.

Significance

By 2010, one out of 15 blind people was blind due to glaucoma, and one of 45 visually impaired people was visually impaired, highlighting the increasing global burden of glaucoma.

Visual Impairment among Older Adults in a Rural Community in Eastern China

Purpose. To determine the prevalence, causes, and associations of visual impairment (VI) among participants aged 60 years or older in a rural community in China. Methods. A community-based survey was undertaken in a rural town located in Eastern China and 4579 people aged 60 years or older participated in the study. Presenting visual acuity was assessed using a Snellen chart with tumbling-E optotypes and anterior segment was examined using a slit-lamp. VI was defined as presenting VA <6/18 and it included moderate VI (<6/18 to 6/60) and blindness (<6/60). Results. The prevalence of VI was 5.4% (95% confidence interval [CI] 4.7–6.0). In multivariate analysis, the presence of VI was positively associated with increasing age (odds ratio [OR] = 1.12, 95% CI 1.10–1.16, per year increase), female gender (OR = 2.33, 95% CI 1.53–3.55), the presence of hypertension (OR = 1.31, 95% CI 1.001–1.85), living alone (OR = 1.52, 95% CI 1.08–2.62), and increased sleeping hours (OR = 1.10, 95% CI 1.001–1.22). Drinking 3 or more glasses of green tea per day was inversely associated with VI (OR = 0.79, 95% CI 0.63–0.98). Conclusion. VI was less prevalent in this community compared with previous report in other areas in China.

Prevalence and causes of low vision and blindness in Baotou: A cross-sectional study

The aim of this study was to investigate the prevalence and causes of low vision and blindness in Baotou, Inner Mongolia.A cross-sectional study was carried out. Multistage sampling was used to select samples. The visual acuity was estimated using LogMAR and corrected by pinhole as best-corrected visual acuity.There were 7000 samples selected and 5770 subjects included in this investigation. The overall bilateral prevalence rates of low vision and blindness were 3.66% (95% CI: 3.17-4.14) and 0.99% (95% CI: 0.73-1.24), respectively. The prevalence of bilateral low vision, blindness, and visual impairment increased with age and decreased with education level. The main leading cause of low vision and blindness was cataract. Diabetic retinopathy and age-related macular degeneration were found to be the second leading causes of blindness in Baotou.The low vision and blindness were more prevalent in elderly people and subjects with low education level in Baotou. Cataract was the main cause for visual impairment and more attention should be paid to fundus diseases. In order to prevent blindness, much more eye care programs should be established.

Age-related macular degeneration and polypoidal choroidal vasculopathy in Asians

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in elderly people globally. It is estimated that there will be more Asians with AMD than the rest of the world combined by 2050. In Asian populations, polypoidal choroidal vasculopathy (PCV) is a common subtype of exudative AMD, while choroidal neovascularization secondary to AMD (CNV-AMD) is the typical subtype in Western populations. The two subtypes share many common clinical features and risk factors, but also have different epidemiological and clinical characteristics, natural history and treatment outcomes that point to distinct pathophysiological processes. Recent research in the fields of genetics, proteomics and imaging has provided further clarification of differences between PCV and CNV-AMD. Importantly, these differences have manifested as disparity in response to intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) treatment between PCV and CNV-AMD, emphasizing the need for accurate diagnosis of PCV and in distinguishing PCV from CNV-AMD, particularly in Asian patients. Current clinical trials of intravitreal anti-VEGF therapy and photodynamic therapy will provide clearer perspectives of evidence-based management of PCV and may lead to paradigm shifts in therapeutic strategies away from those currently employed in the treatment of CNV-AMD. Further research is needed to clarify the relative contribution of specific pathways in inflammation, complement activation, extracellular matrix dysregulation, lipid metabolism and angiogenesis to the pathogenesis of PCV. Findings from this research, together with improved diagnostic technology and new therapeutics, will facilitate more optimal management of Asian AMD.

Population-based assessment of visual impairment among ethnic Dai adults in a rural community in China

Dai ethnicity is one of the major Chinese ethnic minorities with a population of about 1.2 million. We aimed to determine the prevalence and potential causes of visual impairment (VI) among ethnic Dai adults aged 50 years or older in a rural community in China. A population-based survey including 2163 ethnic Dai people (80.5%) was undertaken using a random cluster sampling strategy. The detailed eye examination was performed after pupil dilation by trained study ophthalmologists and optometrists. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) was measured using the Early Treatment Diabetic Retinopathy Study logMAR chart and VI was defined as a VA of less than 20/63 in the better-seeing eye. The overall prevalence of presenting blindness and low vision was 3.0% (95% CI, 2.3-3.7) and 13.3% (95% CI, 11.9-14.8), respectively. The prevalence estimates were reduced to 2.1% (95% CI, 1.5-2.8) and 6.7% (95% CI, 5.7-7.8) when BCVA was considered. Men were more likely to be affected by low vision but less likely to be blind compared with women. Cataract accounted for 62.7% of presenting low vision and 68.8% of presenting blindness, respectively. In conclusion, VI was a significant health concern in Dai Chinese in China.

Impact of Visual Impairment and Eye diseases on Mortality: the Singapore Malay Eye Study (SiMES)

We investigated the relationship of visual impairment (VI) and age-related eye diseases with mortality in a prospective, population-based cohort study of 3,280 Malay adults aged 40–80 years between 2004–2006. Participants underwent a full ophthalmic examination and standardized lens and fundus photographic grading. Visual acuity was measured using logMAR chart. VI was defined as presenting (PVA) and best-corrected (BCVA) visual acuity worse than 0.30 logMAR in the better-seeing eye. Participants were linked with mortality records until 2012. During follow-up (median 7.24 years), 398 (12.2%) persons died. In Cox proportional-hazards models adjusting for relevant factors, participants with VI (PVA) had higher all-cause mortality (hazard ratio[HR], 1.57; 95% confidence interval[CI], 1.25–1.96) and cardiovascular (CVD) mortality (HR 1.75; 95% CI, 1.24–2.49) than participants without. Diabetic retinopathy (DR) was associated with increased all-cause (HR 1.70; 95% CI, 1.25–2.36) and CVD mortality (HR 1.57; 95% CI, 1.05–2.43). Retinal vein occlusion (RVO) was associated with increased CVD mortality (HR 3.14; 95% CI, 1.26–7.73). No significant associations were observed between cataract, glaucoma and age-related macular degeneration with mortality. We conclude that persons with VI were more likely to die than persons without. DR and RVO are markers of CVD mortality.

Integrin αVβ5-mediated Removal of Apoptotic Cell Debris by the Eye Lens and Its Inhibition by UV Light Exposure

Accumulation of apoptotic material is toxic and associated with cataract and other disease states. Identification of mechanisms that prevent accumulation of apoptotic debris is important for establishing the etiology of these diseases. The ocular lens is routinely assaulted by UV light that causes lens cell apoptosis and is associated with cataract formation. To date, no molecular mechanism for removal of toxic apoptotic debris has been identified in the lens. Vesicular debris within lens cells exposed to UV light has been observed raising speculation that lens cells themselves could act as phagocytes to remove toxic apoptotic debris. However, phagocytosis has not been confirmed as a function of the intact eye lens, and no mechanism for lens phagocytosis has been established. Here, we demonstrate that the eye lens is capable of phagocytizing extracellular lens cell debris. Using high throughput RNA sequencing and bioinformatics analysis, we establish that lens epithelial cells express members of the integrin αVβ5-mediated phagocytosis pathway and that internalized cell debris co-localizes with αVβ5 and with RAB7 and Rab-interacting lysosomal protein that are required for phagosome maturation and fusion with lysosomes. We demonstrate that the αVβ5 receptor is required for lens epithelial cell phagocytosis and that UV light treatment of lens epithelial cells results in damage to the αVβ5 receptor with concomitant loss of phagocytosis. These data suggest that loss of αVβ5-mediated phagocytosis by the eye lens could result in accumulation of toxic cell debris that could contribute to UV light-induced cataract formation.

Prevalence of Diabetic Retinopathy and Vision Loss in the Beijing Eye Study: the Potential Role of the Cerebrospinal Fluid Pressure

In the Beijing Eye Study, a population-based study carried out in 2001, 2006, and 2011, prevalence of diabetic retinopathy (DR) was 2.9 ± 0.3 % (95 % confidence interval 2.3, 3.5) per individual in 2011. Correspondingly, only 1.1 % of blindness and 0.8 % of visual impairment were caused by DR in East Asia. As in other populations, prevalence, severity, and 10-year incidence of DR were associated with higher levels of HbA1c, higher blood glucose concentration, longer known duration of diabetes, lower educational level, and higher blood pressure. Interestingly, the presence, severity, and 10-year incidence of DR were additionally correlated with higher estimated cerebrospinal fluid pressure and shorter ocular length. Higher cerebrospinal fluid pressure may lead to higher retinal vein pressure and subsequently higher retinal capillary blood pressure increasing fluid and blood extravasation. Shorter axial length or hyperopia may be associated with higher intraocular concentration of cytokines. Aging of the society, improvements in medical infrastructure, and lifestyle changes may profoundly increase prevalence of, and burden by, DR in China in the future.

Ancestry, Socioeconomic Status, and Age-Related Cataract in Asians: The Singapore Epidemiology of Eye Diseases Study

PURPOSE

To determine the prevalence of age-related cataract and its ancestral and socioeconomic risk factors in a multi-ethnic Asian population.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

A total of 10 033 adults (3353 Chinese, 3280 Malays, and 3400 Indians) aged >40 years in the Singapore Epidemiology of Eye Diseases Study.

METHODS

Study participants were invited for a structured interview and received a standardized comprehensive eye examination. Digital lens photographs were taken from eyes of each participant and graded for nuclear, cortical, and posterior subcapsular (PSC) cataract, following the Wisconsin Cataract Grading System. Prevalence data were compared with the Blue Mountains Eye Study (BMES) in Australia. Information on medical and lifestyle factors was collected using questionnaires and blood samples. To increase the precision of racial definition, genetic ancestry was derived from genome-wide single nucleotide polymorphism markers using principal component analysis. Regression models were used to investigate the association of cataract with socioeconomic factors (education and income) and genetic ancestry.

MAIN OUTCOME MEASURES

Age-related cataract.

RESULTS

A total of 8750 participants (94.0%) had gradable lens photographs. The age-standardized prevalence of cataract surgery in Chinese (16.0%), Malays (10.6%), and Indians (20.2%) was higher than in white subjects (4.1%). We found the age-standardized cataract prevalence in Chinese (30.4%), Malays (37.8%), and Indians (33.1%) was higher than in whites (18.5%). Cataract was 1.5 to 2 times more common in Asians and began 10 years earlier than in white subjects. Malays had significantly higher age-standardized prevalence of nuclear, cortical, and PSC cataract than Chinese (P<0.001). The severity of nuclear, cortical, and PSC cataract was significantly correlated with genetic ancestry in our South East Asian population. Less education and lower income were associated with cataract for Chinese and Indians but not Malays. The presence of visual impairment associated with cataract was higher in people aged ≥60 years and Malays.

CONCLUSIONS

We showed that people of different Asian ethnicities had a higher prevalence and earlier age of onset of cataract than Europeans. People of Malay ancestry have a greater severity for all cataract subtypes than people of Chinese ancestry. Education and income were associated with cataract for certain Asian subgroups.

Polypoidal Choroidal Vasculopathy in Asians

Age related macular degeneration (AMD) in Asians has been suggested to differ from their Western counterparts in terms of epidemiology, pathogenesis, clinical presentation and treatment. In particular, polypoidal choroidal vasculopathy (PCV) appears to be the predominant subtype of exudative AMD in Asian populations, in contrast to choroidal neovascularization secondary to AMD (CNV-AMD) in Western populations. Epidemiological data on PCV has been largely limited to hospital-based studies and there are currently no data on the incidence of PCV. Similarities and differences in risk factor profile between PCV and CNV-AMD point to some shared pathogenic mechanisms but also differential underlying mechanisms leading to the development of each phenotype. Serum biomarkers such as CRP, homocysteine and matrix metalloproteinases suggest underlying inflammation, atherosclerosis and deranged extracellular matrix metabolism as possible pathogenic mechanisms. In addition, recent advances in genome sequencing have revealed differences in genetic determinants of each subtype. While the standard of care for CNV-AMD is anti-vascular endothelial growth factor (VEGF) therapy, photodynamic therapy (PDT) has been the mainstay of treatment for PCV, although long-term visual prognosis remains unsatisfactory. The optimal treatment for PCV requires further clarification, particularly with different types of anti-VEGF agents and possible benefits of reduced fluence PDT.

Thyroid function and age-related macular degeneration: a prospective population-based cohort study--the Rotterdam Study

BACKGROUND

In animal models, lack of thyroid hormone is associated with cone photoreceptor preservation, while administration of high doses of active thyroid hormone leads to deterioration. The association between thyroid function and age-related macular degeneration (AMD) has not been investigated in the general population.

METHODS

Participants of age ≥ 55 years from the Rotterdam Study with thyroid-stimulating hormone (TSH) and/or free thyroxine (FT4) measurements and AMD assessment were included. We conducted age- and sex-adjusted Cox proportional hazards models to explore the association of TSH or FT4 with AMD, in the full range and in those with TSH (0.4-4.0 mIU/L) and/or FT4 in normal range (11-25 pmol/L). Cox proportional hazards models were performed for the association of TSH or FT4 with retinal pigment alterations (RPA), as an early marker of retinal changes. Multivariable models additionally included cardiovascular risk factors and thyroid peroxidase antibodies positivity. We also performed stratification by age and sex. A bidirectional look-up in genome-wide association study (GWAS) data for thyroid parameters and AMD was performed. Single nucleotide polymorphisms (SNPs) that are significantly associated with both phenotypes were identified.

RESULTS

We included 5,573 participants with a median follow-up of 6.9 years (interquartile range 4.4-10.8 years). During follow-up 805 people developed AMD. TSH levels were not associated with increased risk of AMD. Within normal range of FT4, participants in the highest FT4 quintile had a 1.34-fold increased risk of developing AMD, compared to individuals in the middle group (95% confidence interval [CI] 1.07-1.66). Higher FT4 values in the full range were associated with a higher risk of AMD (hazard ratio 1.04, CI, 1.01-1.06 per 1 pmol/L increase). Higher FT4 levels were similarly associated with a higher risk of RPA. Restricting analyses to euthyroid individuals, additional multivariable models, and stratification did not change estimates. We found a SNP (rs943080) in the VEGF-A gene, associated with AMD, to be significant in the TSH GWAS (P = 1.2 x 10(-4)). Adding this SNP to multivariable models did not change estimates.

CONCLUSIONS

Higher FT4 values are associated with increased risk of AMD - even in euthyroid individuals - and increased risk of RPA. Our data suggest an important role of thyroid hormone in pathways leading to AMD.

Validation of Catquest-9SF questionnaire in a Chinese cataract population

PURPOSE

To develop and validate a Chinese version of the Catquest-9SF questionnaire in a cataract population.

METHODS

The Catquest-9SF Questionnaire was translated and back translated into Chinese. Preoperative patients were recruited at a tertiary eye hospital and their demographic information and visual acuity were documented. Psychometric properties of the Catquest-9SF, including ordered thresholds, the ability to distinguish between different strata of person ability, absence of misfitting items, unidimentionality, differential item functioning (DIF) and construct validity were tested, using Rasch analysis.

RESULTS

A total of 102 patients (100% response rate) were enrolled. The participants'mean age was 70.2 year (SD = 12.1) and 46.9% were female. Rasch analysis showed that this version of the questionnaire had ordered response thresholds and was free of DIF. The items fit a single overall construct and unidimensional by principal components analysis of the residuals. Patients with visual impairment had significantly poorer Rasch scores on the Catquest-9SF (mean change, -2.5, p = 0.035, compared with non-visually impaired patients).

CONCLUSION

The Chinese version of Catquest-9SF is a valid and reliable questionnaire for assessing the visual disability outcomes of Chinese patients with cataract, and it may be recommended for routine clinical use.