Visual impairment and spectacle coverage rate in Baoshan district, China: population-based study

The Sleep Health of Individuals with Visual Impairments: A Scoping Review

PURPOSE

Amidst the global aging population and an increasing prevalence of visual impairment across all age groups, this study aims to investigate the current state of research on sleep health in visually impaired populations.

METHODS

A scoping review was conducted to synthesize the existing literature on sleep health and visual impairment. We employed conceptual mapping to identify key research topics, analyzing data from four databases: PubMed (n = 290), CINAHL (n = 81), Scopus (n = 117), and PsycInfo (n = 96). A total of 83 peer-reviewed articles, published from 1977 to August 2023, were included in the review.

RESULTS

Our analysis identified 11 distinct eye health conditions including blindness, glaucoma, diabetic retinopathy, low vision, cataract, retinitis pigmentosa, macular degeneration, optic neuropathy, visual field defects, ocular hypertension, and retinal vein occlusion. Additionally, 8 major sleep problems were recognized: abnormal sleep duration, daytime sleepiness, insomnia, Non-24-Hour Sleep Wake Disorder, sleep apnea, sleep disorders, sleep disturbances, and sleep disordered breathing. The dominant research themes were (1) poor sleep quality in individuals with visual impairments and ophthalmic diseases, (2) high prevalence of sleep issues in patients with ophthalmic diseases, (3) sleep apnea in patients with ophthalmic conditions, and (4) circadian rhythm disruptions in blind individuals.

CONCLUSION

This review highlights research gaps that, when addressed, could greatly enhance our comprehension of the interplay between visual impairment and sleep health. Bridging these gaps promises to lead to more holistic care strategies, potentially improving vision functioning and rehabilitation outcomes for individuals with visual impairments.

Barriers to the Utilization of Low-Vision Rehabilitation Services among Over-50-Year-Old People in East and Southeast Asian Regions: A Scoping Review

East and Southeast Asia (ESEA) are facing age-related eye health issues. Low-vision rehabilitation (LVR), which is a special rehabilitation service for individuals with vision impairment, is a promising solution for these health issues; however, poor accessibility to LVR services has been reported globally, including ESEA. Therefore, this scoping review aimed to summarize and understand the barriers to accessing LVR services in ESEA. In total, 20 articles were ultimately considered eligible for this scoping review after an electronic database search using MEDLINE (PubMed), Web of Science, Academic Search Ultimate (EBSCO), and Ichushi-Web (Japanese medical literature database), and an independent review by two reviewers. Twenty-one potential barrier factors were identified in the full-text review. Notably, age, education, economic status, "previous experience using eye care service", and "knowledge, information, and awareness" were the possible barrier factors that were examined for their association with LVR utilization, with supportive evidence in many eligible studies. We also identified research gaps relating to geographical and ethnic diversity, the scope of LVR services, and barriers among eligible articles. Therefore, by conducting further studies addressing the research gaps identified in this scoping review, these findings can be used to make LVR services more accessible to people in ESEA.

Epidemiology and trends in the uptake of refractive error services in Harare, Zimbabwe: a hospital-based retrospective study

Aim

The study aimed to determine the epidemiology and evaluate the trends in the uptake of refractive error services in Harare.

Methods

A clinic-based retrospective study at the Greenwood Park Eye Centre and its three subsidiaries was conducted from January 1, 2015 to December 31, 2020.

Results

12,216 patients' records were retrieved, out of which 1074 (8.79%) had refractive error cases. The prevalence of visual impairment at presentation was 5.80% [95% CI: 5.39 - 6.23]. Among those with refractive error, the sample prevalence of visual impairment before correction was 41.30% [CI: 38.3 - 44.3, 95%], and 2.20% [95% CI: 1.4 - 3.3] after correction. There was inconsistency in the percentage utilization of refractive error services, with the highest being 42.60% in 2015. Refractive error types were related to age, employment position, and type of visual impairment prior to refractive error treatment.

Conclusion

There was a low percentage of refractive error services uptake in urban Zimbabwe.

Prevalence of uncorrected distance refractive errors and associated risk factors in employees of an academic centre

BACKGROUND

Uncorrected refractive error (RE) may affect the work performance of adults in the workplace. The aim of current study was to determine the prevalence of corrected and uncorrected RE, and the determinants of uncorrected RE in adult employees of a university.

METHODS

This was a cross-sectional study of Tehran University Medical Sciences' staff. Besides demographic and some specific questionnaires, ophthalmic examinations including the measurement of uncorrected visual acuity (UCVA), best spectacles corrected visual acuity (BCVA), and presenting visual acuity were performed for all participants. The need for spectacles was defined as UCVA worse than 6/12 in the better eye that could be corrected to better than 6/12 with spectacles based on subjective refraction.

RESULTS

In total, 4460 individuals with mean age of 42.32 ± 8.80 were included in the study. The VA of the better eye was 0.01 ± 0.05 logMAR for BCVA, 0.13 ± 0.26 for UCVA, and 0.05 ± 0.12 for presenting VA. Prevalence of RE was 15.7%, including uncorrected RE of 5% and spectacles coverage (corrected RE) of 10.7%. The proportion of individuals with elementary education and poor-fair status of general health were 1.62 times higher in the uncorrected group. In the univariate analysis, type of occupation (office versus non-office workers), socioeconomic status, and insurance of employees were not related to uncorrected RE (all P > 0.4). Myopia was the only factor associated with uncorrected RE in logistic regression analysis (odds ratio = 2.73, 95%CI = 1.02-7.31, P = 0.04).

CONCLUSION

The prevalence of uncorrected RE and spectacle coverage were 5% and 10.7%, respectively. Myopia was almost three times more likely to be associated among employees with uncorrected RE.

Spectacle Coverage Rate After Cataract Surgery in an Urban Area in Indonesia

Purpose

Uncorrected refractive errors after cataract surgery contribute to visual impairments. The aim of this study was to investigate the spectacle coverage rate (SCR) following cataract surgery and its relationship with socioeconomic factors in an urban city in Indonesia.

Patients and Methods

This population-based cross-sectional study was conducted in 2015 in Jakarta. The former participants of the Rapid Assessment of Avoidable Blindness (RAAB) survey had a history of cataract surgery and met either of the following criteria: (1) wore spectacles with presenting visual acuity (PVA) 6/12 or (2) had PVA less than 6/12 regardless of spectacle use but achieved the best visual acuity (BVA) 6/12 with pinhole correction.

Results

Of the 2998 participants of the RAAB survey, 173 (5.6%) (252 eyes) had a history of cataract surgery, among whom 53 (86 eyes) met our inclusion criteria. The SCR was 69.8% and was associated with age group, household income level, education level, and physicians' recommendation of spectacle wear. Participants who were of nonproductive age (80%), had the highest household income level (88.2%), the highest level of education (87.5%), and had been recommended for spectacle use by their physicians (80.9%) demonstrated higher SCR. Participants with the highest household income had the highest SCR. Patients who had received a physician's recommendation showed a higher SCR and were 26 times more likely to wear spectacles (odds ratio [OR] 25.99, 95% CI 2.59-260.10).

Conclusion

There is an unmet need for refractive errors after cataract surgery. Factors such as household income levels and physician recommendations were predictive of spectacle wear.

Ethnic Disparities in Risk Factors for Myopia among Han and Minority Schoolchildren in Shawan, Xinjiang, China

SIGNIFICANCE

The ethnic differences in myopia rates, ocular dimensions, and risk factors between Han and non-Han schoolchildren observed in this study may help fill the knowledge gap about ethnic minorities and are important for China and other countries to address vision-related health inequalities among different ethnic groups.

PURPOSE

This study aimed to investigate the risk factors of juvenile myopia and elucidate the disparities of risk factors among Han and non-Han school students in Xinjiang, China.

METHODS

A population-based cross-sectional study of 876 schoolchildren from grades 1 to 9 was conducted in the Anjihai Middle School in Shawan, Xinjiang Uygur Autonomous Region, China. Visual acuity and ocular biometry were assessed, and personal information, including behavior, birth status, and familial factors, was collected using self-made standardized questionnaires.

RESULTS

The myopia rate among students of Han ethnicity (50.5%) was the highest, followed by Hui (41.3%) and Uygur et al. (32.0%, P < .001). Similar patterns were observed for mean axial length. The mean axial lengths are 23.7, 23.4, and 23.3 mm, respectively ( P = .01). Overall, performing high-quality eye exercises, longer sleep duration, being born in summer, parental smoking, and consuming more food containing anthocyanins were all associated with a lower incidence of myopia. Meanwhile, Han ethnicity, intensive near task, bad eye habits, and myopic mothers were associated with higher odds of myopia. After adjusting for environmental influences pertaining to myopia, the variation in myopia prevalence between Han and Uygur et al. remained significant, whereas it changed to not significant between Han and Hui ethnicities.

CONCLUSIONS

Significant disparities were found in the prevalence of myopia among various ethnic groups in Shawan, Xinjiang. Life habits, birth status, and familial factors may contribute to such variance and play different roles in the occurrence of juvenile myopia among various ethnicities.

Trends in the prevalence of vision impairment among the oldest-old Chinese population from 1998 to 2018

Background

Vision impairment has become a prominent public health issue worldwide. However, little is known about vision impairment prevalence trends among the oldest-old adults in China. This study aimed to examine 20-year trends in the prevalence of vision impairment among the oldest-old Chinese adults and explore the contributions of sociodemographic variables, health behaviours, and chronic conditions to the trends.

Methods

This retrospective longitudinal study used data from the Chinese Longitudinal Healthy Longevity Survey during 1998-2018. A total of 45 849 participants aged ≥80 years at study entry were included. Vision impairment was assessed by an adapted Landolt-C chart at each wave. We examined unadjusted and adjusted nonlinear trends using generalized estimating equation models incorporating a natural cubic spline. We conducted linear regression models to estimate absolute annual prevalence changes and determine the contributions of sociodemographic variables, health behaviours, and chronic conditions to the trends.

Results

The fully adjusted prevalence doubled from 5.5% (95% confidence interval (CI) = 5.1%-6.0%) in 1998 to 10.7% (95% CI = 9.9%-11.5%) in 2011 and slightly increased to 11.1% (95% CI = 10.3%-12.0%) in 2018 among the oldest-old Chinese population. Glaucoma, cataracts, cognitive impairment, hearing impairment, and urban residence were significant contributors to changes in vision impairment prevalence during 1998-2018. Differences in vision impairment prevalence associated with glaucoma and cataracts narrowed since 2005. Disparities in the trends among cognitively impaired and unimpaired older adults remained unchanged over time. Similar results were observed in older people with and without hearing impairment.

Conclusions

Vision impairment prevalence among the oldest-old Chinese population increased from 1998 to 2011 and remained stable from 2011 to 2018. Future work is needed to improve the prevention and management of chronic diseases associated with vision impairment to reduce its prevalence.

Estimating need and coverage for five priority assistive products: a systematic review of global population-based research

INTRODUCTION

To improve access to assistive products (APs) globally, data must be available to inform evidence-based decision-making, policy development and evaluation, and market-shaping interventions.

METHODS

This systematic review was undertaken to identify studies presenting population-based estimates of need and coverage for five APs (hearing aids, limb prostheses, wheelchairs, glasses and personal digital assistants) grouped by four functional domains (hearing, mobility, vision and cognition).

RESULTS

Data including 656 AP access indicators were extracted from 207 studies, most of which (n=199, 96%) were cross-sectional, either collecting primary (n=167) or using secondary (n=32) data. There was considerable heterogeneity in assessment approaches used and how AP indicators were reported; over half (n=110) used a combination of clinical and self-reported assessment data. Of 35 studies reporting AP use out of all people with functional difficulty in the corresponding functional domains, the proportions ranged from 4.5% to 47.0% for hearing aids, from 0.9% to 17.6% for mobility devices, and from 0.1% to 86.6% for near and distance glasses. Studies reporting AP need indicators demonstrated >60% unmet need for each of the five APs in most settings.

CONCLUSION

Variation in definitions of indicators of AP access have likely led to overestimates/underestimates of need and coverage, particularly, where the relationship between functioning difficulty and the need for an AP is complex. This review demonstrates high unmet need for APs globally, due in part to disparate data across this sector, and emphasises the need to standardise AP data collection and reporting strategies to provide a comparable evidence base to improve access to APs.

Improving Access to Refractive Services in Adults: A Health Examination Center-Based Model

Purpose: To assess the potential of a health examination center-based screening model in improving service for uncorrected refractive error. Methods: Individuals aged ≥18 years undergoing the routine physical examinations at a tertiary hospital in the northeast China were invited. Presenting visual acuity, noncycloplegic autorefraction, noncontact tonometry, fundus photography, and slit-lamp examination were performed. Refractive error was defined as having spherical equivalent ≤ -0.75 D or ≥ +1 D and uncorrected refractive error was considered as refractive error combined with presenting visual acuity < 6/12 in the better eye. Costs for the screening were assessed. Results: A total of 5,284 participants (61 ± 14 years) were included. The overall prevalence of myopia and hyperopia was 38.7% (95% CI, 37.4-40.0%) and 23.5% (95% CI, 22.3-24.6%), respectively. The prevalence of uncorrected refractive error was 7.85% (95% CI, 7.13-8.58%). Women (p < 0.001 and p = 0.003), those with age ≥ 70 years (p < 0.001 and p = 0.003), and myopia (p < 0.001 and p < 0.001) were at higher risk of uncorrected refractive error and uncorrected refractive error-related visual impairment. Spectacle coverage rate was 70.6% (95% CI, 68.2-73.0%). The cost to identify a single case of refractive error and uncorrected refractive error was US$3.2 and US$25.2, respectively. Conclusion: The prevalence of uncorrected refractive error is high in the urban Chinese adults. Health examination center-based refractive error screening is able to provide an efficient and low-cost model to improve the refractive services in China.

Knowledge and Attitude of Refractive Error Among Public High School Students in Gondar City

INTRODUCTION

Refractive error (RE) is the main cause of visual impairment and blindness in the world. Lack of knowledge and unfavorable attitude of refractive error can have long-term consequences and dramatic effects in children and adults, such as loss of educational and employment opportunities, loss of economic gain for individuals, families, and societies, and impaired quality of life.

AIM

The aim of this study was to assess the level of knowledge and attitude of refractive error among public high school students in Gondar city, Northwest Ethiopia.

METHODS

A school-based cross-sectional study was conducted on 390 public high school students. Those participants were selected by applying a systematic random sampling technique with an interval of 4. Data were collected using a pre-tested structured questionnaire through face-to-face interviews. The collected data were entered into Epi Info version 7.0 and exported into SPSS version 20 for analysis. Results were described using tables and text.

RESULTS

A total of 390 study participants were included in this study with a 92.4% response rate. The overall proportion of good knowledge and a favorable attitude towards a refractive error were 53.8% and 52.1%, respectively. From the study participants, 38.7%, 41.7%, and 64.1% did not know the definition, the risk factors, and the symptoms of refractive error, respectively. Moreover, about 31.3% of the participants believed that wearing spectacle could damage their eyes, whereas 44.1% of the participants agreed with the need for spectacle correction for young people with RE.

CONCLUSION

The proportion of good knowledge and a favorable attitude towards refractive error among public high school students were fair. We recommended that eye care practitioners be committed to increasing the knowledge and attitude of students towards refractive error through eye health education to reduce visual impairment due to refractive error.

Population-based assessment of prevalence of spectacle use and effective spectacle coverage for distance vision in Andhra Pradesh, India - Akividu Visual Impairment Study

CLINICAL RELEVANCE

Effective spectacle coverage is a useful indicator to assess the coverage of refraction services in a given region. We found a low coverage in the Akividu region suggesting a need to develop effective refraction services.

BACKGROUND

To assess the prevalence of spectacle use and effective spectacle coverage for distance vision among people aged 40 years and older in the Indian state of Andhra Pradesh.

METHODS

A population-based cross-sectional survey was carried out in the Akividu region in West Godavari and Krishna districts. The study teams visited selected households and conducted eye examinations in the selected clusters. A structured questionnaire was used to collect information on spectacle use. 'Met Need' was defined as unaided VA worse than 6/12 but improved to 6/12 or better with their current spectacles. 'Unmet Need' was defined as unaided VA worse than 6/12 but improved to 6/12 with pinhole, among those not using spectacles. The 'Under-met Need' was defined as aided VA worse than 6/12 but improving with pinhole to 6/12 or better. Based on these definitions, Effective Refractive Error Coverage (e-REC) is calculated as: e-REC (%) s = ((met need)/(met need + under-met need + unmet need)) X100.

RESULTS

Of 3,000 enumerated from 60 clusters, 2,587 (86.2%) participants were examined. The prevalence of current spectacle use was 43.1% (95% CI:41.2-45.0). The e-REC was 37.4%. It was also lower in men compared to women and among those without any education. Participants who had cataract surgery in either eye had similar e-REC compared to those who were not operated.

CONCLUSION

Though spectacle use was found to be high, there is a still large unmet need for refractive correction for distance. Effective service delivery models to provide refraction and spectacle dispensing services are needed to achieve universal eye health coverage in the region.

TuYou-County Pediatric Eye (TYPE) study, design issues, baseline demographic characteristics, and implications: Report number 1

To report the rationale, design, and baseline demographic characteristics of TuYou-County Pediatric Eye study, which mainly aimed to determine the retinal microvascular changes with optical coherence tomography angiography (OCTA) and its association with eye abnormalities in school aged children and adolescents at suburban location in Northern China.TuYou-County Pediatric Eye study was a school-based survey conducted in TuYou-County. Multi-ethnic (Mongol, Han, and Hui) participants will be followed up for 5 years. Standardized ophthalmological examinations include visual acuity, ocular biometry, retinal photography, and OCTA. A questionnaire survey was conducted to collect variables regarding to eye disease such as parental history of eye diseases, near work, outdoor activities, living and eating habits, etc.After sampling, 687 participants were eligible for investigation, and 20 students did not attend the investigation, living 667 (response rate, 97.1%) students completed questionnaires and all ocular examinations. The average age of all participants was 14.9 ± 5.11.TYPE study is the first large-scale school-based multi-ethnic survey in suburban site of Northern China. Continuous identification of retinal microvascular changes with eye diseases will provide new insights into the control related diseases in school-age children and adolescents.

The prevalence and causes of visual impairment among ethnic Tujia adults in a rural community in China

We aimed to investigate the prevalence and causes of visual impairment (VI) in an elderly Tujia ethnic rural population in Southwest China.From June 1 to December 31, 2018, a random cluster sampling survey was conducted among Tujia individuals aged 50 years or older in the rural areas of Qianjiang District County in Chongqing. The sampling design used village-based clusters of approximately equal size (1000 people). The sampling frame was composed of 110 clusters including 26,527 adults aged 50 years or older; 10 clusters (2556 adults) were randomly selected, and 2122 subjects were examined. Ophthalmologic examinations and questionnaires were administered to all the participants. Low vision and blindness were defined using best-corrected visual acuity (BCVA) and presenting visual acuity, according to The World Health Organization standard. The prevalence of VI was estimated, and causes of VI were identified.The participation rate was 83.0%. The prevalence of VI was 15.2% (BCVA 8.0%). In the study population, the prevalence of low vision and blindness increased with age (P < .05) and was higher among those with a low education level (P < .01). The majority of VI was attributed to cataracts (50.0%) and uncorrected refractive error (35.7%). With BCVA, cataract (79.3%) was the most common cause of VI, followed by age-related macular degeneration (10.7%).The main causes of VI in Tujia ethnic were cataracts and refractive errors. Both cataracts and refractive errors are curable eye diseases; thus, local health institutions need to adopt a more active eye care project as a strategy to prevent blindness.

Near Vision Spectacle Coverage and Associated Factors Among Adults Living in Finote Selam Town, Northwest Ethiopia: Community-Based Cross-Sectional Study

Background

Near visual impairment leads to difficulty with near tasks at a working distance (40 centimeters) when near visual acuity is 6/12 (N8) or worse. High cost is the main barrier reported for low near vision spectacle coverage.

Objective

This study aimed to determine near vision spectacle coverage and associated factors among adults living in Finote Selam town, Northwest Ethiopia.

Methods

A community-based, cross-sectional study was applied from June 3 to 25, 2019. A total of 565 study participants aged ≥35 years were recruited using a systematic random sampling technique. A pre-tested questionnaire with adequate physical examination was used for data collection. The data were entered into EPI INFO software and exported to a statistical package for science for analysis. Mean (standard), frequencies, tables, and figures were used to present descriptive statistics. A bi-variable and multivariable logistic regression was used to determine the association between independent variables and outcome variable with a P-value of less than 0.20 and a P-value of less than 0.05, respectively. Odds ratios and a 95% confidence interval were used to show strength of association.

Results

A total of 549 adults participated, with a response rate of 97.20% and a mean age of 46.4±8.7 years. The near vision spectacle coverage was 156 (28.42%; 95% CI=24.65-32.31). Higher education level (AOR=2.8; 95% CI=1.21-5.21), history of eye examination (AOR=2.40; 95% CI=1.51-3.81), awareness about near vision problems (AOR=2.12; 95% CI=1.41-3.24), and need of a high plus lens (AOR=4.21; 95% CI=2.41-7.39) were associated with near vision spectacle coverage.

Conclusion

Near vision spectacle coverage was low among adults living in Finote Selam town. Higher educational level, history of eye examination, awareness about near vision problems, and need of a high plus lens were associated with near vision spectacle coverage.

Incidence of ocular conditions associated with perfluoroalkyl substances exposure: Isomers of C8 Health Project in China

The detrimental effects of perfluoroalkyl substances (PFASs) on several physiological systems have been reported, but the association of PFASs with eye, one of the most sensitive and exposed organ, has never been explored. To investigate the association between eye diseases including visual impairment (VI) and PFASs isomers, a cross-sectional stratified study was conducted in 1202 Chinese population, aged 22-96 years, from Shenyang, China. A standard protocol including Snellen vision chart, slit-lamp microscopy and direct ophthalmoscopy was used to examine eye diseases/conditions relating to anterior and posterior segment of eyes. In addition, we measured the blood concentrations of 19 linear and branched PFASs at one-time point. Results indicated that blood levels of PFASs were significantly higher in eye disease group than normal group. PFASs exposure were positively associated with both combined eye diseases and individual eye diseases. Among other PFASs, linear perfluorooctane sulfonate (n-PFOS; odds ratio [OR] = 3.37, 95% confidence interval [CI]: 2.50, 4.56), branched perfluorooctane sulfonate (Br-PFOS; OR = 2.25, 95% CI: 1.72, 2.93) and linear perfluorooctanoic acid (n-PFOA; OR = 1.79, 95% CI: 1.36, 2.37) significantly increases the odds of VI. Vitreous disorder was adversely associated with long-chain PFASs exposure. For example, perfluorotridecanoic acid (PFTrDA; OR = 1.86, 95% CI: 1.51, 2.29) and perfluorodecanoic acid (PFDA; OR = 1.79, 95% CI: 1.36, 2.36) showed the most significant association. In conclusion, this study suggests higher serum PFASs levels were associated with increase odds of VI and vitreous disorder in Chinese adults.

Use of spectacles for distance vision: coverage, unmet needs and barriers in a rural area of North India

Background

Uncorrected refractive errors contribute enormously to the burden of avoidable visual impairment worldwide. There is a huge disparity in different parts of the globe in context to spectacle coverage for distance vision. This study was undertaken with objectives of determining prevalence of spectacle coverage, unmet needs and associated factors among adults in a rural community of north India.

Methods

A community-based cross-sectional study was carried out within selected clusters of Jhajjar district of Haryana. All participants aged > 15 years underwent visual acuity assessment by LogMAR “E” screening chart. Participants with presenting visual acuity < 6/12 in any eye and all current spectacle users underwent detailed ophthalmic examination and refraction. Additional details about spectacles, barriers for their use and willingness to pay for them were collected. Participants with met and unmet need for spectacle use at visual acuity > 6/12 was computed. These are reported as proportions with 95% confidence intervals. Associated factors with unmet need were determined using bivariable and multivariable logistic regression analysis.

Results

A total of 6910 participants were examined. The current spectacle use was 7.5% (95% Confidence Interval CI: 6.5, 8.7). The spectacle coverage was found in 33.3% (95% CI: 30.0, 36.7) participants among those in need. The unmet need was found in 10.8% of participants (95% CI: 10.1, 11.6). On multivariable analysis, odds of unmet need was associated with age, gender, level of education and marriage status. The most common barrier for refractive correction was lack of perceived need for refraction and its correction.

Conclusion

There is substantial unmet need for distance vision spectacles in this population. It is imperative that multi-component intervention be implemented to improve spectacle coverage in this rural north Indian setting.

Visual Impairment and Spectacle Use in University Students in Central China: The Anyang University Students Eye Study

PURPOSE

To investigate the prevalence and associations of visual impairment and spectacle use in university students in central China.

DESIGN

Cross-sectional study.

METHODS

This study included students aged 16-26 years in China. Study subjects from 2 universities underwent distance visual acuity (VA) assessment in both eyes with a logarithm of the minimum angle of resolution chart and their refractions were measured by cycloplegic autorefraction. Blindness was defined as presenting VA less than three-sixtieth in the better eye (World Health Organization definition), and visual impairment was defined as presenting VA less than six-twelfths.

RESULTS

Overall, 9710 undergraduates were enumerated, 7704 (79.3%) subjects were included in this study. The prevalence of uncorrected VA less than six-twelfths and less than three-sixtieth in the better eye were 69.9% and 0.9%, respectively. Only 77.0% (4148/5388) of subjects with uncorrected VA in the better eye of less than six-twelfths wore glasses. For presenting VA, the prevalence of mild (VA <6/12 to 6/18), moderate (VA <6/18 to 6/60), and severe (VA <6/60 to 3/60) visual impairment was 6.3%, 11.2%, and 0.7%, respectively. Overall, 71.7% (4300/6001) of students with myopia (spherical equivalent ≤-0.5 diopters) wore spectacles. In multiple logistic regression analysis, visual impairment was associated with female sex (P < .001) and lower year level of education (P = .006) when presenting with VA.

CONCLUSIONS

This study has documented a relatively high prevalence of visual impairment and relatively low spectacle coverage in Chinese university students. Given the potential impact of visual impairment, target education and accessible refraction services are highly important to solve the problem.

Prevalence of visual impairment and its association with vision-related quality of life among elderly persons in a resettlement colony of Delhi

Background:

The population of India is ageing. The number and percentage of elderly persons is increasing. Visual impairment is common among elderly persons and affects their vision-related quality of life. The objective of this study was to estimate the prevalence of visual impairment among elderly persons aged 60 years and above residing in a resettlement colony of Delhi and study its association with socio-demographic variables and vision-related quality of life.

Methods:

A total of 604 elderly participants were selected by simple random sampling. House-to-house visit was done, and a self-developed pre-tested semi-structured interview schedule was used to collect socio-demographic information. Visual acuity was measured using Snellen's chart, and distant direct ophthalmoscopy was done to diagnose cataract. Vision-related quality of life was assessed by Indian Vision Function Questionnaire-33 (IND-VFQ-33).

Results:

Of the 604 participants, 555 (91.9%) were available for interview. The prevalence of visual impairment was 24.5% (95% CI: 20.9% - 28.1%). Cataract was the leading cause of visual impairment (50.7%), followed by uncorrected refractive error (36.8%). Illiteracy (aOR: 3.49, 1.37-8.87), economic dependence on family members (aOR: 1.92, 1.04 – 3.54), not currently working (aOR: 1.89, 1.20-2.98) and chewing of tobacco products (aOR: 2.56, 1.48-4.42) were significantly associated with visual impairment among study participants. Vison-related quality of life was worse among those with visual impairment.

Conclusion:

Burden of visual impairment is high among elderly persons living in urban resettlement colonies. It is largely avoidable. Eye-care services should be accessible and affordable to them.

The prevalence of vision impairment and refractive error in 3654 first year students at Tianjin Medical University

AIM

To determine the prevalence of vision impairment (VI) and refractive error in first year university students at the Tianjin Medical University.

METHODS

This is a cross-sectional observational cohort study of VI and refractive error among first year university students at the Tianjin Medical University. The first year university students were involved in this study and were given a detailed questionnaire including age, birth date, and spectacle wearing history. A standardized ophthalmologic examination including visual acuity (VA), slit-lamp examination, non-cycloplegic auto-refraction, objective refraction, fundus photography, and examination of their spectacles were recorded.

RESULTS

A total of 3654 participants were included in this study. Totally 3436 (94.03%) individuals had VI in this population. Totally 150 (4.10%) individuals had VI due to ocular disease, including amblyopia, congenital cataract, retinal atrophy or degeneration, strabismus, congenital nystagmus, refractive surgery orthokeratology. Totally 3286 (89.93%) subjects had VI due to refractive error. Only 218 (5.97%) students were emmetropia. Moreover, refractive error was the main cause for the VI (95.63%). Totally 3242 (92.52%) students were myopia and the prevalence of mild, moderate, and high myopia subgroup was 27.05%, 44.35%, and 21.26% respectively. Totally 44 (1.29%) subjects were hyperopic. The rates of uncorrected visual acuity (UCVA), presenting visual acuity (PVA) and best corrected visual acuity (BCVA) which better than 20/20 in both eyes were 5.65%, 22.32% and 82.13% respectively. The rates of correction, under correction and well correction in myopia subjects were 82.73%, 84.39% and 15.61%, respectively.

CONCLUSION

We present a high prevalence of refractive errors and high rates of under correction refractive error among first year university students. These results may help to promote vision protection work in young adults.

Potential Lost Productivity Resulting from the Global Burden of Myopia: Systematic Review, Meta-analysis, and Modeling

PURPOSE

We estimated the potential global economic productivity loss resulting from vision impairment (VI) and blindness as a result of uncorrected myopia and myopic macular degeneration (MMD) in 2015.

CLINICAL RELEVANCE

Understanding the economic burden of VI associated with myopia is critical to addressing myopia as an increasingly prevalent public health problem.

METHODS

We estimated the number of people with myopia and MMD corresponding to critical visual acuity thresholds. Spectacle correction coverage was analyzed against country-level variables from the year of data collection; variation in spectacle correction was described best by a model based on a human development index, with adjustments for urbanization and age. Spectacle correction and myopia data were combined to estimate the number of people with each level of VI resulting from uncorrected myopia. We then applied disability weights, labor force participation rates, employment rates, and gross domestic product per capita to estimate the potential productivity lost among individuals with each level and type of VI resulting from myopia in 2015 in United States dollars (US$). An estimate of care-associated productivity loss also was included.

RESULTS

People with myopia are less likely to have adequate optical correction if they are older and live in a rural area of a less developed country. The global potential productivity loss associated with the burden of VI in 2015 was estimated at US$244 billion (95% confidence interval [CI], US$49 billion-US$697 billion) from uncorrected myopia and US$6 billion (95% CI, US$2 billion-US$17 billion) from MMD. Our estimates suggest that the Southeast Asia, South Asia, and East Asia Global Burden of Disease regions bear the greatest potential burden as a proportion of their economic activity, whereas East Asia bears the greatest potential burden in absolute terms.

CONCLUSIONS

Even under conservative assumptions, the potential productivity loss associated with VI and blindness resulting from uncorrected myopia is substantially greater than the cost of correcting myopia.

Population need for primary eye care in Rwanda: A national survey

Background

Universal access to Primary Eye Care (PEC) is a key global initiative to reduce and prevent avoidable causes of visual impairment (VI). PEC can address minor eye conditions, simple forms of uncorrected refractive error (URE) and create a referral pathway for specialist eye care, thus offering a potential solution to a lack of eye health specialists in low-income countries. However, there is little information on the population need for PEC, including prevalence of URE in all ages in Sub-Saharan Africa.

Methods

A national survey was conducted of people aged 7 and over in Rwanda in September-December 2016. Participants were selected through two-stage probability proportional to size sampling and compact segment sampling. VI (visual acuity<6/12) was assessed using Portable Eye Examination Kit (PEEK); URE was detected using a pinhole and presbyopia using local near vision test. We also used validated questionnaires to collect socio-demographic and minor eye symptoms information. Prevalence estimates for VI, URE and need for PEC (URE, presbyopia with good distance vision, need for referrals and minor eye conditions) were age and sex standardized to the Rwandan population. Associations between age, sex, socio-economic status and the key outcomes were examined using logistic regression.

Results

4618 participants were examined and interviewed out of 5361 enumerated (86% response rate). The adjusted population prevalence of VI was 3.7% (95%CI = 3.0–4.5%), URE was 2.2% (95%CI = 1.7–2.8%) and overall need for PEC was 34.0% (95%CI = 31.8–36.4%). Women and older people were more likely to need PEC and require a referral.

Conclusions

Nearly a third of the population in Rwanda has the potential to benefit from PEC, with greater need identified in older people and women. Universal access to PEC can address unmet eye health needs and public health planning needs to ensure equitable access to older people and women.

Prevalence and causes of visual impairment amongst older adults in a rural area of North India: a cross-sectional study

OBJECTIVES

To determine the prevalence, causes and associated factors for visual impairment (VI) in rural population of Jhajjar district, Haryana, north India.

METHODS

A community-based, cross-sectional study was conducted in two blocks of Jhajjar district. A total of 34 villages were selected using probability proportionate to size sampling method. Adults aged 50 years and above were selected using compact segment cluster sampling approach. Presenting visual acuity using LogMAR E chart was measured along with collection of other demographic details as part of the house-to-house survey. Subjective refraction and torch light examination were performed at a clinic site within the village to ascertain VI and its cause. VI was considered when presenting visual acuity was less than 6/18 in the better eye. Common causes of VI viz uncorrected refractive errors, cataract, central corneal opacity and others were noted by optometrists. Descriptive analysis was undertaken. Multivariate logistic regression analysis was performed for determining associated factors with VI.

RESULTS

Out of 2025 enumerated adults, 1690 (83.5%) were examined at the household level and 1575 (78%) completed all study procedures. The prevalence of VI was found to be 24.5% (95% CI 21.1 to 26.3) and blindness was 5% (95% CI 3.9 to 6.1). The most common causes of VI were uncorrected refractive errors (50%) and cataract (37%). The VI in study participants was found to be associated with age, gender, marital and educational status.

CONCLUSIONS

VI is still a public health problem in rural population of Jhajjar district, Haryana. Provision of spectacles and cataract surgical services are simple interventions to address this issue.

Prevalence and associated risk factors of undercorrected refractive errors among people with diabetes in Shanghai

Background

To investigate the prevalence and risk factors of undercorrected refractive error (URE) among people with diabetes in the Baoshan District of Shanghai, where data for undercorrected refractive error are limited.

Methods

The study was a population-based survey of 649 persons (aged 60 years or older) with diabetes in Baoshan, Shanghai in 2009. One copy of the questionnaire was completed for each subject. Examinations included a standardized refraction and measurement of presenting and best-corrected visual acuity (BCVA), tonometry, slit lamp biomicroscopy, and fundus photography.

Results

The calculated age-standardized prevalence rate of URE was 16.63% (95% confidence interval [CI] 13.76–19.49). For visual impairment subjects (presenting vision worse than 20/40 in the better eye), the prevalence of URE was up to 61.11%, and 75.93% of subjects could achieve visual acuity improvement by at least one line using appropriate spectacles. Under multiple logistic regression analysis, older age, female gender, non-farmer, increasing degree of myopia, lens opacities status, diabetic retinopathy (DR), body mass index (BMI) index lower than normal, and poor glycaemic control were associated with higher URE levels. Wearing distance eyeglasses was a protective factor for URE.

Conclusion

The undercorrected refractive error in diabetic adults was high in Shanghai. Health education and regular refractive assessment are needed for diabetic adults. Persons with diabetes should be more aware that poor vision is often correctable, especially for those with risk factors.

The met and unmet need for refractive correction and its determinants in 7-year-old children

Refractive errors are the leading cause of visual impairment and at the same time the most treatable cause of visual impairment in children and students. The aim of this study is to determine the prevalence of the unmet need for refractive correction and the spectacle coverage rate among 7-year-old Iranian children with refractive errors. The present cross-sectional study was performed in 2013 through multistage cluster sampling across eight cities in Iran. For all students, noncycloplegic autorefraction was done by a technician. The unmet need for glasses was defined as the ratio of people who did not have glasses or their vision with their current glasses was worse than 6/12 despite achieving 6/12 or better visual acuity with proper correction. A total of 67 schools were selected by multistage cluster sampling; 4106 subjects participated in the study (response rate, 89%), and 48.2% ( n = 1979) were girls. The prevalence of spectacle need was 4.11% (95% confidence interval [CI: 3.19–5.04]), the unmet need was 2.74% (95% CI [1.89–3.59]), and the spectacle coverage rate (met need/[met need + unmet need]) was 33.3%. Also, the unmet need in children whose families were in the lower income quartile was 7.14 times the rate seen in children in the upper income quartile. The concentration index for the unmet need was −.27 (±.05). The findings of this study confirm that in light of the detrimental effects of refractive errors in schoolchildren’s academic progress and their future, identification of the students who live in poorer families and have multiple risk factors for developing vision disorders should be a health priority.

Main visual symptoms associated to refractive errors and spectacle need in a Brazilian population

AIM

To determine the main visual symptoms in a Brazilian population sample, associated to refractive errors (REs) and spectacle need to suggest priorities in preventive programs.

METHODS

A cross-sectional study was conducted in nine counties of the southeast region of Brazil, using a systematic sampling of households, between March 2004 and July 2005. The population was defined as individuals aged between 1 and 96y, inhabitants of 3600 residences to be evaluated and 3012 households were included, corresponding to 8010 subjects considered for participation in the survey, of whom 7654 underwent ophthalmic examinations. The individuals were evaluated according their demographic data, eye complaints and eye examination including the RE and the need to prescribe spectacles according to age. Statistical analysis was performed using SPSS software package and descriptive analysis using 95% confidence intervals (P<0.05).

RESULTS

The main symptom detected was asthenopia, most frequent in the 2^nd and 3^rd decades of life, with a significant decline after the 4^th decade. Astigmatism was the RE most associated with asthenopia. Reduced near vision sight was more frequent in those ≥40y with a progressive decline thereafter. Spectacles were most frequently required in subjects of ≥40 years of age.

CONCLUSION

The main symptom related to the vision was asthenopia and was associated to astigmatism. The greatest need for spectacles prescription occurred after 40's, mainly to correct near vision. Subjects of ≥40 years old were determined to be at high risk of uncorrected REs. These observations can guide intervention programs for the Brazilian population.

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.

Rapid assessment of visual impairment in urban population of Delhi, India

Purpose

To determine the prevalence, causes and associated demographic factors related to visual impairment amongst the urban population of New Delhi, India.

Methods

A population-based, cross-sectional study was conducted in East Delhi district using cluster random sampling methodology. This Rapid Assessment of Visual Impairment (RAVI) survey involved examination of all individuals aged 40 years and above in 24 randomly selected clusters of the district. Visual acuity (VA) assessment and comprehensive ocular examination were done during the door-to-door survey. A questionnaire was used to collect personal and demographic information of the study population. Blindness and Visual Impairment was defined as presenting VA <3/60and <6/18 in the better eye, respectively. Descriptive statistics were computed along with multivariable logistic regression analysis to determine associated factors for visual impairment.

Results

Of 2421 subjects enumerated, 2331 (96.3%) were available for ophthalmic examination. Among those examined, 49.3% were males. The prevalence of visual impairment (VI) in the study population, was 11.4% (95% C.I. 10.1, 12.7) and that of blindness was 1.2% (95% C.I. 0.8, 1.6). Uncorrected refractive error was the leading cause of VI accounting for 53.4% of all VI followed by cataract (33.8%). With multivariable logistic regression, the odds of having VI increased with age (OR= 24.6[95% C.I.: 14.9, 40.7]; p<0.001). Illiterate participants were more likely to have VI [OR= 1.5 (95% C.I.: 1.1,2.1)] when compared to educated participants.

Conclusions

The first implementation of the RAVI methodology in a North Indian population revealed that the burden of visual impairment is considerable in this region despite availability of adequate eye care facilities. Awareness generation and simple interventions like cataract surgery and provision of spectacles will help to eliminate the major causes of blindness and visual impairment in this region.

Prevalence and causes of visual impairment and rate of wearing spectacles in schools for children of migrant workers in Shanghai, China

Background

To assess the prevalence of visual impairment and rate of wearing spectacles in schools for children of migrant workers in Shanghai, China.

Methods

Children from grade 1 to 5 in schools for children of migrant workers were randomly chosen for ocular examinations. All children were screened for uncorrected visual acuity and presenting visual acuity. After screening, the children whose uncorrected visual acuity was 20/40 or less received ocular motility evaluation, cycloplegic refraction/non-cycloplegic refraction, and external eye, anterior segment, media, and fundus examinations.

Results

A total of 9673 children were enumerated and 9512 (98.34%) participated in this study. The prevalence of uncorrected, presenting, and best-corrected visual acuity of 20/40 or worse in the better eye were 13.33%, 11.26%, and 0.63%, respectively. The rate of wearing spectacles of the children with visual impairment in one or both eyes was 15.50%. Of these, 26.05% were wearing spectacles with inaccurate prescriptions. Refractive error was a major cause of visual impairment, accounting for 89.48% of all the visual impairment causes. Other causes of visual impairment included amblyopia accounting for 10.12%; congenital cataract, 0.1%; congenital nystagmus, 0.1%; ocular prosthesis, 0.1%; macular degeneration, 0.05%; and opaque cornea, 0.05%.

Conclusions

This is the first study of the prevalence and causes of visual impairment in schools for children of migrant workers in Shanghai, China. The visual impairment rate in schools for children of migrant workers in suburbs of Shanghai in the best eye before vision correction was lower than those of urban children in mainstream schools in Guangzhou in 2012, and higher than students in rural of Beijing in 1998 and in suburb of Chongqing in 2007. The refractive error was the principal cause of the visual impairment of the children of migrant workers. The rate of wearing spectacles was low and the percentage of inaccurate prescriptions, among those who wore spectacles, was high. Uncorrected refractive error was a significant cause of visual impairment in migrant children.

The control effect of orthokeratology on axial length elongation in Chinese children with myopia

BACKGROUND

To retrospectively compare axial elongation in children with different degrees of myopia wearing spectacles and undergoing ortho-k treatment.

METHODS

The medical records of 128 patients who were fitted with spectacles or orthokeratology (ortho-k) lenses in our clinic between 2008 and 2009 were reviewed. Ortho-k group comprised 65 subjects and 63 subjects wearing spectacles were included in the control group. Subjects were also divided into low-myopia, moderate-myopia and high-myopia groups, based on the basic spherical equivalent refractive error. Axial length periodically measured over 2-year of lens wear and changes in axial length were compared between treatment groups and between subgroups with different degrees of myopia.

RESULTS

The control group exhibited more changes in axial length than the ortho-k group at both 12 months (0.39 ± 0.21 mm vs 0.16 ± 0.17 mm, p <0.001) and 24 months (0.70 ± 0.35 mm vs 0.34 ± 0.29 mm, p <0.001). Axial length elongation was estimated to be slower by about 51% in the ortho-k group. Similar results were found for the subgroups (49%, 59% and 46% reductions, respectively). In the group with low and moderate myopia, the annual increases in axial length were significantly different between the ortho-k and control groups during both the first ( Low myopia: 0.19 ± 0.17 mm vs 0.40 ± 0.18 mm, p = 0.001; Moderate myopia: 0.14 ± 0.18 mm vs 0.45 ± 0.22 mm, p <0.001) and second ( Low myopia: 0.18 ± 0.14 mm vs 0.32 ± 0.19 mm, p = 0.012; Moderate myopia: 0.18 ± 0.16 mm vs 0.34 ± 0.30 mm, p = 0.030) years. In the high myopia groups, significant differences were only found between the ortho-k and control groups during the first year (0.16 ± 0.18 mm vs 0.34 ± 0.22 mm, p = 0.004). The 2-year axial elongation was significantly associated with initial age (p <0.001) and treatment (p <0.001), but not with gender, initial refractive error, initial axial length, initial corneal curvature.

CONCLUSIONS

This 2-year study indicates that ortho-k contact lens wear is effective for reducing myopia progression in children with low, moderate and high myopia.

Influence of uncorrected refractive error and unmet refractive error on visual impairment in a Brazilian population

BACKGROUND

The World Health Organization (WHO) definitions of blindness and visual impairment are widely based on best-corrected visual acuity excluding uncorrected refractive errors (URE) as a visual impairment cause. Recently, URE was included as a cause of visual impairment, thus emphasizing the burden of visual impairment due to refractive error (RE) worldwide is substantially higher. The purpose of the present study is to determine the reversal of visual impairment and blindness in the population correcting RE and possible associations between RE and individual characteristics.

METHODS

A cross-sectional study was conducted in nine counties of the western region of state of São Paulo, using systematic and random sampling of households between March 2004 and July 2005. Individuals aged more than 1 year old were included and were evaluated for demographic data, eye complaints, history, and eye exam, including no corrected visual acuity (NCVA), best corrected vision acuity (BCVA), automatic and manual refractive examination. The definition adopted for URE was applied to individuals with NCVA > 0.15 logMAR and BCVA ≤ 0.15 logMAR after refractive correction and unmet refractive error (UREN), individuals who had visual impairment or blindness (NCVA > 0.5 logMAR) and BCVA ≤ 0.5 logMAR after optical correction.

RESULTS

A total of 70.2% of subjects had normal NCVA. URE was detected in 13.8%. Prevalence of 4.6% of optically reversible low vision and 1.8% of blindness reversible by optical correction were found. UREN was detected in 6.5% of individuals, more frequently observed in women over the age of 50 and in higher RE carriers. Visual impairment related to eye diseases is not reversible with spectacles. Using multivariate analysis, associations between URE and UREN with regard to sex, age and RE was observed.

CONCLUSION

RE is an important cause of reversible blindness and low vision in the Brazilian population.