Uncorrected refractive errors and spectacle utilisation rate in Tehran: the unmet need

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.

Effect of Myopic Undercorrection on Habitual Reading Distance in Schoolchildren: The Hong Kong Children Eye Study

INTRODUCTION

This study aimed to evaluate the habitual reading distance among non-myopic children and also myopic children with undercorrection and with full correction.

METHODS

This was a population-based cross-sectional study with a total of 2363 children aged 6-8 years who were recruited from the Hong Kong Children Eye Study. Cycloplegic autorefraction, subjective refraction, habitual visual acuity, and best corrected visual acuity were measured. The entire reading process (9 min) was recorded using a hidden video camera placed 5 m away from the reading desk. Reading distances were taken at 6, 7, 8, and 9 min after the child began reading and were measured using a customized computer program developed in MATLAB. The main outcome was the association of habitual reading distances with refraction status. Habitual reading distances of children were documented via video camera footage.

RESULTS

The habitual reading distances of undercorrected myopic children (23.37 ± 4.31 cm) were the shortest when compared to non-myopic children (24.20 ± 4.73 cm, P = 0.002) and fully corrected myopic children (24.81 ± 5.21 cm, P < 0.001), while there was no significant difference between the last two children groups (P = 0.17). A shorter reading distance was associated with myopia (OR 1.67; 95% CI 1.11-2.51; P = 0.013) after adjusting for age, sex, height, near work time, outdoor time, and parental myopia. The association of reading distance with myopia did not hold after undercorrected myopic children were excluded (OR 0.97, 95% CI 0.55-1.73; P = 0.92). A shorter reading distance correlated with poorer vision under habitual correction (β = - 0.003, P < 0.001).

CONCLUSION

A shorter reading distance was present among undercorrected myopic children. Myopia undercorrection is not recommended as a strategy for slowing myopic progression.

A Study to Analyze Refractive Errors in Relation to Age and Sex

Background and objective Refractive defects should be detected and treated early to avoid irreversible vision loss and other potential problems in the future. In this study, we aimed to analyze the refractive errors (REs) and their relationship with gender and age. Methods This study was conducted at the Northern Border University Health Center, Arar, Saudi Arabia. REs were analyzed using spherical equivalents (SEs), cylinders, and their orientations. SEs of REs were taken as half the cylinder plus the spherical component. Emmetropia was defined as SE between -0.50 and +0.50 diopter sphere (DS), myopia as SE ≤0.50 DS, and hyperopia as SE ≥0.50 DS for adults and SE ≥1.0 for children (up to 10 years). Statistical analysis was performed using the IBM SPSS Statistics software package (IBM, Armonk, NY). Qualitative data were presented as frequency and percentage while quantitative data were presented as mean and standard deviation (SD). Chi-square was used as a significant test and a p-value <0.05 was considered statistically significant. Results A total of 240 patients were included in the study. There were 138 men and 102 females aged 3-60 years (57.5 and 42.5%, respectively). The mean age of males was 24.4 years and that of females was 25.5 years. The p-value was statistically significant in terms of analysis with age. The study found an association between age and RE magnitude and variability. Conclusion Based on our findings, RE is a common problem that affects individuals of all ages. Regular screenings are advised for individuals in order to detect REs early.

Risk Factors for Uncorrected Refractive Error: Persian Cohort Eye Study - Rafsanjan Center

Purpose

To determine the prevalence of visually significant uncorrected refractive error (URE) in Rafsanjan and investigate the related factors. URE is the leading cause of visual impairment (VI) which causes the second-highest number of years lived with disability. The URE is a preventable health problem.

Methods

In this cross-sectional study participants from Rafsanjan who were 35-70 years were enrolled between 2014 and 2020. Demographic and clinical characteristics data were gathered, and eye examination was performed. Visually significant URE was defined as present if habitual visual acuity was (HVA; visual acuity with present optical correction) >0.3 logMAR in the best eye and the visual acuity of that eye showed >0.2 logMAR improvement after the best correction. Logistic regression was used to determine the association between predicting variables (age, sex, wealth, education, employment, diabetes, cataract, and refractive error characteristics) and outcome (URE).

Results

Among the 6991 participants of Rafsanjan subcohort of the Persian Eye Cohort, 311 (4.4%) had a visually significant URE. Diabetes was significantly more prevalent in the participants with visually significant URE, at 18.7% versus 13.1% in patients without significant URE (P = 0.004). In the final model, each year of increase in age was associated with 3% higher URE (95% confidence interval [CI]: 1.01-1.05). In comparison to low hyperopia, participants with low myopia had 5.17 times more odds of visually significant URE (95% CI: 3.38-7.93). However, antimetropia decreased the risk of visually significant URE (95% CI: 0.02-0.37).

Conclusion

Policymakers should pay special attention to elderly patients with myopia to effectively reduce the prevalence of visually significant URE.

The prevalence and causes of pediatric uncorrected refractive error: Pooled data from population studies for Global Burden of Disease (GBD) sub-regions

Background

There are limited systematic reviews on the prevalence of uncorrected refractive errors in children. We aimed to summarize the prevalence and causes of pediatric uncorrected refractive error (URE) from studies in the Global Burden of Disease (GBD) sub-regions.

Methods

The pooled analysis used the individual participant data (ages less than 20 years old) from population-based studies around the world by regions. URE was defined as presenting VA < 6/18 and improving to ≥ 6/18 or ≥1 line on using a pinhole in either eye, with main causes of myopia, hyperopia or astigmatism. Each study provided data on any URE, myopia, hyperopia or astigmatism by age, gender, and ethnicity. Prevalence rates were directly age and gender standardized to the 2020 world population with all age groups. Estimates were calculated by study and sub-regions after pooling. Summary estimates included studies in which URE was assessed from a pinhole-corrected refraction in the better eye.

Results

The combined pooled data contained 302,513,219 patients including 8 963 URE cases individuals from 57 studies. Prevalence varied by age and GBD sub-regions and differed by gender. The age- and region-standardized prevalence of URE was 3.41 per 1000 (CI, 1.53~7.62) in Western Pacific region (12 studies), 2.26 per 1000 (CI, 0.85~6.01) in South-East Asia region (14 studies), 5.85 per 1000 (CI, 3.75~9.13) in Americans (11 studies) and 4.40 per 1000 (CI, 3.0~6.45) in Eastern Mediterranean region (13 studies). On the basis of these data, myopia was the first-leading cause in female children with 12~17 age group, with the prevalence rate 18.2 per 1000 (CI, 11.52~23.61). Astigmatism was detected in 27.2 per 1000 male children with 6~11 age group (CI: 19.12–30.68).

Conclusions

Prevalence of URE available data within these sub-regions are widely disparate. Myopia and astigmatism in young age children continue as the leading cause of URE worldwide. Providing appropriate refractive correction to those individuals whose vision can be improved is an important public health endeavor with implications for safety and quality of life.

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.

Visual Impairment, Major Eye Diseases, and Mortality in a Multi-Ethnic Asian Population and a Meta-analysis of Prospective Studies

PURPOSE

Vision impairment (VI) is associated with poor quality of life and increased risk of falls. Few prospective data are available on Asians. This study investigates the longitudinal impact of VI and the major eye diseases on mortality risk in Asians.

DESIGN

Prospective cohort study with meta-analysis.

METHODS

We conducted a multi-ethnic prospective study of adults (40-80 years old) in the Singapore Epidemiology of Eye Diseases Study (baseline: 2004-2011). All-cause mortality was obtained from the National Death Registry until May 2017. VI was defined by best-corrected visual acuity (BCVA) <20/40 in the better eye. Major eye diseases were assessed using standard protocols. We examined associations using multivariate-adjusted Cox proportional hazards regression models. Finally, we conducted a meta-analysis of the associations between VI and mortality.

RESULTS

Of 9,986 participants, 1,210 deaths occurred (12.1%) over a median follow-up of 8.8 years. Compared to participants with normal vision, persons with VI had increased risk of mortality (hazards ratio [HR]: 1.53; 95% confidence interval [CI:] 1.30-1.81) in multivariate models. In ethnicity-specific analyses, this association was significant across Chinese (HR: 1.63; 95% CI: 1.08-2.48); Malays (HR: 1.31; 95% CI: 1.06-1.62); and Indians (HR: 2.25; 95% CI: 1.61-3.15). Cataract, under-corrected refractive errors (URE), and diabetic retinopathy (DR) were significantly associated with mortality (HRs: 1.30, 1.22, and 1.54, respectively). In a meta-analysis of 12 studies including 58,034 persons, VI was associated with 30% increased risk of mortality (HR: 1.3; 95% CI: 1.2-1.5).

CONCLUSIONS

In this multi-ethnic Asian population, VI and preventable eye conditions (cataract, URE, and DR) were associated with mortality, emphasizing the need for early detection and intervention to prevent and treat VI and major eye diseases.

Global disease burden of uncorrected refractive error among adolescents from 1990 to 2019

Background

To estimate the global disease burden of uncorrected refractive error (URE) among adolescents and assess the contributions of various risk factors to disability-adjusted life-years (DALYs) due to URE.

Methods

Global, regional and country-level DALY numbers and rates due to URE among adolescents were acquired from the Global Burden of Disease Study 2019 database. Human Development Index (HDI), Socio-Demographic Index (SDI) and other country-level data were obtained from other open databases as potential indicators. Regression analysis was used to evaluate associations between DALY rates among adolescents and potential predictors.

Results

Global DALYs due to URE among adolescents rose by 8% between 1990 and 2019 but moderately decreased by 4.8% during this period after adjusting for population size. Female adolescents showed higher DALY rates. DALY rates sharply increased from 5 to 9 years of age, then rose more slowly, reaching a plateau before 20 years of age. Country-level DALY rates in 2019 were positively associated with HDI, SDI, and urbanization rates but negatively correlated with primary school dropout rates. Higher disease burden of adolescents visually impaired from URE was associated with lower primary school dropout rates (β = − 0.257, 95% CI − 0.376 to − 0.138, P < 0.001) and higher urbanization rates (β = 0.257, 95% CI 0.067 to 0.256, P = 0.001).

Conclusions

Higher socioeconomic status, urbanization rates and education levels are associated with a heavier disease burden of URE among adolescents. The findings of this study can provide a reference for policy making on resource allocation for URE prevention and control in teenagers.

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.

Prevalence of Uncorrected Refractive Error and Its Risk Factors; Tehran Geriatric Eye Study (TGES)

Purpose: To determine the age-sex-standardized prevalence of uncorrected refractive error and its determinantsMethods: This population-based cross-sectional study was conducted on 3310 people aged≥ 60 years in Tehran, Iran in 2019. Need for spectacles was defined as uncorrected visual acuity worse than 20/40 in better eye that could be corrected to more than 20/40 with suitable spectacles. Met need was defined as proportion of individuals with need for spectacles whose visual acuity was 20/40 or better with current spectacles. Unmet need was defined as proportion of individuals with need for spectacles who needed but did not have spectacles or their visual acuity was worse than 20/40 with current spectacles while suitable spectacles improved their visual acuity to 20/40 or better.Results: The age-sex-standardized prevalence of need for spectacles, met need, and unmet need was 16.67% (95% CI: 15.33-18.09), 7.81% (95% CI: 6.95-8.78), and 8.85% (95% CI: 7.77-10.07), respectively. Myopic subjects had the highest prevalence of need for spectacles (24.06%, 95% CI: 21.47-26.87). The odds ratio of met and unmet need in subjects≥ 80 years versus those aged 60-65 years was 0.36 (p-value: 0.009) and 2.34 (p-value: <0.001), respectively. The odds ratio of met and unmet need in subjects with a university education versus illiterate subjects was 1.72 (p-value: 0.045) and 0.42 (p-value: 0.007), respectively.Conclusion: The prevalence of uncorrected refractive error was lower in this study compared to previous studies. The met need rate was lower in subjects with older age and lower education levels.

Economic Inequality in Unmet Refractive Error Need in Deprived Rural Population of Iran

Purpose:

To determine economic inequality in unmet refractive error (RE) need and its determinants in deprived rural population of Iran.

Methods:

In this population-based study, two villages were randomly selected from among underserved villages of Iran. After selecting the participants, optometric examinations, including uncorrected and corrected visual acuity and subjective and manifest refraction, were done for all the participants. Then, unmet need for glasses was determined. Concentration index (C) was used to assess inequality, and Oaxaca–Blinder decomposition method was applied to decompose the gap between the two groups based on the determinants.

Results:

Of 3851 samples, 3314 participated in the study (response rate = 86.05%). The data of 3255 participants were used for analysis. The value of C and 95% confidence interval (CI) was −0.088 (−0.157 to −0.020), indicating a pro-poor inequality in unmet need. The prevalence (95% CI) of unmet need was 11.74% (9.25–14.22) in the poor and 6.51% (4.96–8.06) in the rich, with a gap of about 5% in favor of the rich (P < 0.001). A marked percentage of the gap was due to the explained portion (b = 5.73; P = 0.031). In the explained portion, the variable of economic status (b = 3.48; P = 0.004) and myopia (b = 0.88; P = 0.031) caused inequality in favor of the rich and against the poor, respectively. In the unexplained portion (b = −0.51; P = 0.372), the variables of education (P = 0.002) and place (P = 0.001) had statistically significant effects on inequality.

Conclusions:

There is a significant pro-poor economic inequality in the prevalence of unmet need in rural areas of Iran. Although part of this inequality is related to variables such as education and myopia, a major portion (two thirds) of this inequality may be due to the direct effect of economic inequality.

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.

The reduction of horizontal inequity in unmet refractive error: The Shahroud Eye Cohort Study, 2009-2014

Purpose

To measure Horizontal Inequity Index (HI) of unmet refractive error and its changes between 2009 and 2014 in Iran.

Methods

The data used in this study was taken from population-based study, Shahroud Eye Cohort Study. The number of participants analyzed in first (2009) and second phases of study (2014) were 5190 and 4737, respectively, and individuals between 40 and 64 years were included. The HI was determined by using the Concentration Index (C) based on the nonlinear (Probit) model, and C was decomposed to identify and quantify the contribution of each factor.

Results

After adjusting for need variables, the results demonstrated that the HI in unmet refractive need decreased from −0.288 (95% CI: 0.370, −0.206) in the 2009 to −0.132 (95% CI: 0.290, −0.028) in 2014. Decomposition of the C showed that level of education and economic status were the greatest contributors with shares of 26.2% and 17.9%, respectively, in reducing the amount of HI in unmet refractive error between 2009 and 2014.

Conclusions

The current study demonstrated that unmet refractive error did not have an equal distribution among economic quintiles, despite the same need for correcting refractive errors. Reducing the amount of HI in unmet refractive error between 2009 and 2014 indicated an improvement in the unmet need in the five years period between two phases of study.

Ophthalmic Care Utilization and Out-of-Pocket Expenditure in Iran: Kurdistan Eye Health and Economics Survey-2015

BACKGROUND

Due to lack of information about ophthalmic economics in Iran, health policy makers unable to distribute resources optimally in terms of efficiency and equity. Therefore, we estimated the total and eye care utilization, out-of-pocket expenditures, and its association with social determinants of health in Iran in 2015.

METHODS

A multi-stage population-based, cross-sectional study in a random sample aged 50 yr or older in Kurdistan Province, Northwest Iran was used. The utilization rate of eye and general health care and related out-of-pocket expenditures was estimated during the recent last six months. To find the association between social factors and care out-of-pocket expenditures, we used a Heckman two-step regression model.

RESULTS

About 81% and 37% of participants were utilized the health and ophthalmic services, respectively. Statistically significant lower ophthalmic utilization rates were observed among men, middle-aged population, illiterate participants, rural residents, daily-paid workers, and the poorest participants. The average of vision and total health-related out-of-pocket expenditures among those used these services have estimated as US$43.7 (SE: 2.6) and US$439.9 (SE: 22.8), respectively. The highest (US$ 396.6) and lowest (US$ 10.4) ophthalmic out-of-pocket costs were related to patients with Glaucoma and Central Nervous System abnormalities, respectively. Multivariate analyses confirmed an unequal probability of having the ophthalmic out-of-pocket expenditures among different subgroups especially in favor of females, older, and those with more severe visual impairment.

CONCLUSION

Ophthalmic disorders reconstituted about 10% of all health services OOP expenditures on average among individuals older than 50 yr.

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.

Spectacles use in a rural population in the state of Telangana in South India

CONTEXT

Uncorrected refractive errors are the leading cause of visual impairment.

AIMS

To assess the prevalence and patterns of spectacles use among those aged ≥40 years in the South Indian state of Telangana.

SETTINGS AND DESIGN

This was a population-based, cross-sectional study, in which 6150 people were enumerated from 123 clusters in the two districts of Telangana state (Adilabad and Mahbubnagar) using a two-stage cluster random sampling methodology.

MATERIALS AND METHODS

Participants were visited in their households and presenting visual acuity (VA) was assessed in all cases followed by pinhole VA if presenting VA was worse than 6/12. A questionnaire was used to collect information on the current and previous spectacles use, type of spectacles, and details of the spectacles provider.

STATISTICAL ANALYSIS USED

Stata statistical software version 12.

RESULTS

Among 5881 participants examined, 53.7% were women, and 82% had no formal education. The prevalence of current spectacles use was 28.8% (95% confidence interval: 27.6-30.0). On applying multiple logistic regression analysis, spectacles use was significantly associated with older age groups, female gender, higher levels of education, and residing in Adilabad district. Bifocals were the most commonly used type of spectacles (56.3%), and private eye clinics (70.3%) were the leading service providers. The spectacles coverage was 53.6%.

CONCLUSIONS

We reported on prevalence and patterns of spectacles use using a large representative sample and a high response rate. More than half of those who may benefit from spectacles were using them, suggestive of a reasonable primary eye care coverage in the two districts studied.

Prevalence of visual impairment due to uncorrected refractive error: Results from Delhi-Rapid Assessment of Visual Impairment Study

AIM

To estimate the prevalence of visual impairment (VI) due to uncorrected refractive error (URE) and to assess the barriers to utilization of services in the adult urban population of Delhi.

MATERIALS AND METHODS

A population-based rapid assessment of VI was conducted among people aged 40 years and above in 24 randomly selected clusters of East Delhi district. Presenting visual acuity (PVA) was assessed in each eye using Snellen's "E" chart. Pinhole examination was done if PVA was <20/60 in either eye and ocular examination to ascertain the cause of VI. Barriers to utilization of services for refractive error were recorded with questionnaires.

RESULTS

Of 2421 individuals enumerated, 2331 (96%) individuals were examined. Females were 50.7% among them. The mean age of all examined subjects was 51.32 ± 10.5 years (standard deviation). VI in either eye due to URE was present in 275 individuals (11.8%, 95% confidence interval [CI]: 10.5-13.1). URE was identified as the most common cause (53.4%) of VI. The overall prevalence of VI due to URE in the study population was 6.1% (95% CI: 5.1-7.0). The elder population as well as females were more likely to have VI due to URE (odds ratio [OR] = 12.3; P < 0.001 and OR = 1.5; P < 0.02). Lack of felt need was the most common reported barrier (31.5%).

CONCLUSIONS

The prevalence of VI due to URE among the urban adult population of Delhi is still high despite the availability of abundant eye care facilities. The majority of reported barriers are related to human behavior and attitude toward the refractive error. Understanding these aspects will help in planning appropriate strategies to eliminate VI due to URE.

Excimer laser refractive surgery rate in Iran: 2010-2014

Purpose

To determine the rate of excimer laser refractive surgery in Iran and its trend during 2010–2014, and the number of surgeries per ophthalmologist.

Methods

Twelve provinces were considered for the study; 4 major referral provinces of Tehran, Fars, Isfahan, and Khorasan, and 8 others which were selected randomly. Then a number of excimer laser centers were chosen from each province. In the timeframe between 2010 and 2014, one week per season was randomly selected for each center, and the number of surgeries conducted in these 20 weeks was determined by trained personnel.

Results

In the 12 surveyed provinces, 28 of the 57 active surgical centers were selected. The rate of excimer laser refractive surgery in 2010 in Iran was 2764 per million population which reached 3744 per million by 2012 and took a slightly decreasing trend to 3582 until 2014. Based on the number of ophthalmologists and the number of surgeries in 2014, the average number of surgeries per ophthalmologist was 103 surgeries.

Conclusion

This is the first study to report the rate of excimer laser refractive surgery in Iran.

The prevalence of uncorrected refractive errors in underserved rural areas

Purpose

To determine the prevalence of uncorrected refractive errors, need for spectacles, and the determinants of unmet need in underserved rural areas of Iran.

Methods

In a cross-sectional study, multistage cluster sampling was done in 2 underserved rural areas of Iran. Then, all subjects underwent vision testing and ophthalmic examinations including the measurement of uncorrected visual acuity (UCVA), best corrected visual acuity, visual acuity with current spectacles, auto-refraction, retinoscopy, and subjective refraction. Need for spectacles was defined as UCVA worse than 20/40 in the better eye that could be corrected to better than 20/40 with suitable spectacles.

Results

Of the 3851 selected individuals, 3314 participated in the study. Among participants, 18.94% [95% confidence intervals (CI): 13.48–24.39] needed spectacles and 11.23% (95% CI: 7.57–14.89) had an unmet need. The prevalence of need for spectacles was 46.8% and 23.8% in myopic and hyperopic participants, respectively. The prevalence of unmet need was 27% in myopic, 15.8% in hyperopic, and 25.46% in astigmatic participants. Multiple logistic regression showed that education and type of refractive errors were associated with uncorrected refractive errors; the odds of uncorrected refractive errors were highest in illiterate participants, and the odds of unmet need were 12.13, 5.1, and 4.92 times higher in myopic, hyperopic and astigmatic participants as compared with emmetropic individuals.

Conclusion

The prevalence of uncorrected refractive errors was rather high in our study. Since rural areas have less access to health care facilities, special attention to the correction of refractive errors in these areas, especially with inexpensive methods like spectacles, can prevent a major proportion of visual impairment.

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.

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.

Attitude and beliefs of Nigerian undergraduates to spectacle wear

BACKGROUND

Uncorrected refractive error is a common cause of preventable visual impairment. Glasses are the cheapest and commonest form of correction of refractive errors. To achieve this, patients must exhibit good compliance to spectacle wear. Patients' attitude and perception of glasses and eye health could affect compliance to spectacle wear.

OBJECTIVE

To determine the attitude and beliefs of Nigerian undergraduates to spectacle wear.

METHOD

A cross sectional study of 500 undergraduates of the University of Benin, Nigeria. Age range was from 18 to 30 years, mean age 23 ± 2.7 years. There were 269 males and 231 females. Semi structured questionnaires were distributed to the participants and collected same day after completion.

RESULTS

Two-thirds (68%) of the total population studied had not heard of refractive error. About a third (38%) believed wearing eyeglasses was one of the methods used to correct refractive error. Half (50%) believed they would wear spectacles if prescribed with one by their doctor. Sixty-four percent believed eyeglasses are harmful to the eyes; and 65% did not know that eyeglasses could be used to relieve other forms of ocular discomfort like headache and tearing. Fifty-seven per cent of respondents saw people who wore eyeglasses as visually handicapped, while 60% believed that eyeglasses were meant for old people. Majority of the respondents (56%) believed that they would be teased if they wore glasses.

CONCLUSION

Knowledge of refractive errors and acceptance of glasses for the correction of refractive errors among Nigerian undergraduates is not encouraging. Public enlightenment programs to promote benefits of wearing prescribed spectacles are needed.

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

Background

To investigate the prevalence and risk factors of visual impairment associated with refractive error and the unmet need for spectacles in a special suburban senior population in Baoshan District of Shanghai, one of several rural areas undergoing a transition from rural to urban area, where data of visual impairment are limited.

Methods

The study was a population based survey of 4545 Chinese aged (age: >60 years or older ) at Baoshan, Shanghai, in 2009. One copy of questionnaire was completed for each subject. Examinations included a standardized refraction and measurement of presenting and best corrected visual acuity (BCVA) as well as tonometry, slit lamp biomicroscopy, and fundus photography.

Results

The prevalence of mild (6/12 to 6/18), moderate (6/18 to 6/60) and severe visual impairment was 12.59%, 8.38% and 0.44%, respectively, and 5.26%, 3.06% and 0.09% with refractive correction. Visual impairment was associated with age, gender, education and career, but not insurance . The prevalence of correctable visual impairment was 5.81% (using 6/18 cutoff) and 13.18% (using 6/12 cutoff). Senior people and women were significantly at a higher risk of correctable visual impairment, while the well-educated on the contrary. The prevalence of undercorrected refractive error (improves by 2 or more lines with refraction) was 24.84%, and the proportion with undercorrected refractive error for mild, moderate , severe and no visual impairment was 61.54%, 67.98%, 60.00% and 14.10%, respectively. The spectacle coverage rate was 44.12%. Greater unmet need for spectacles was observed among elderly people, females, non-peasant, and subjects with less education and astigmatism only.

Conclusions

High prevalence of visual impairment, visual impairment alleviated by refractive correction, and low spectacle coverage existed among the senior population in Baoshan District of Shanghai. Education for the public of the importance of regular examination and appropriate and accessible refraction service might be helpful to solve the problem.

Cohort profile: Shahroud Eye Cohort Study

The Shahroud Eye Cohort Study was set up to determine the prevalence and incidence of visual impairment and major eye conditions in the 40-64-year-old population of Shahroud as a Middle Eastern population. The first phase of the study was conducted in 2009-10. Using random cluster sampling, 6311 Shahroud inhabitants were invited for ophthalmologic examinations; of these, 5190 participants completed phase 1 (participation rate of 82.2%). All participants were interviewed to collect data on participants' demographics, occupation status, socioeconomic status, history of smoking, and medical and ophthalmic history, as well as history of medication, and the quality and duration of their insurance. DNA and plasma samples, as well as four dots of whole blood were collected from participants. Extensive optometric and ophthalmologic examinations were performed for each participant, including lensometry of current glasses, testing near and far visual acuity; determining objective and subjective refraction; eye motility; cycloplegic refraction; colour vision test; slit-lamp biomicroscopy and intraocular pressure measurement; direct and indirect fundoscopy; perimetry test; ocular biometry; corneal topography; lens and fundus photography; and the Schirmer's (1008 participants) and tear breakup time tests (1013 participants). The study data are available for collaborative research at Noor Ophthalmology Research Center, Tehran, Iran.

Uncorrected refractive error in older British adults: the EPIC-Norfolk Eye Study

AIM

To investigate the prevalence of, and demographic associations with, uncorrected refractive error (URE) in an older British population.

METHODS

Data from 4428 participants, aged 48-89 years, who attended an eye examination in the third health check of the European Prospective Investigation into Cancer-Norfolk study and had also undergone an ophthalmic examination were assessed. URE was defined as ≥1 line improvement of visual acuity with pinhole-correction in the better eye in participants with LogMar presenting visual acuity (PVA) <0.3 (PVA <6/12). Refractive error was measured using an autorefractor without cycloplegia. Myopia was defined as spherical equivalent ≤-0.5 dioptre, and hypermetropia ≥0.5 dioptre.

RESULTS

Adjusted to the 2010 midyear British population, the prevalence of URE in this Norfolk population was 1.9% (95% CI 0.6% to 3.1%). Lower self-rated distance vision was correlated with higher prevalence of URE (p(trend)<0.001). In a multivariate logistic regression model adjusting for age, gender, retirement status, educational level and social class, independent significant associations with URE were increasing age (p(trend)<0.001) and having hypermetropic or myopic refractive error. Wearing distance spectacles was inversely associated with URE (OR 0.34, 95% CI 0.21 to 0.55, p<0.001). There were 3063 people (69.2%) who wore spectacles/contact lenses for distance vision. Spectacle wear differed according to type of refractive error (p<0.001), and use rose with increasing severity of refractive error (p(trend)<0.001).

CONCLUSION

Although refractive error is common, the prevalence of URE was found to be low in this population reflecting a low prevalence of PVA<0.3.

Unmet refractive need and its determinants in Shahroud, Iran

Uncorrected refractive error plays a significant role in poor vision and blindness, and its correction is the most cost-effective intervention in eye care. In this study, we report the status of the unmet refractive need and the role of economic inequality in determining the level of this need in Shahroud, Iran. This cross-sectional nested case-control study was performed on 5,190 individuals aged 40-64 years. Cases and controls were individuals with uncorrected visual acuity worse than 0.3 LogMAR in the better eye who showed at least 0.2 LogMAR improvement after correction. Cases were individuals whose presenting vision was worse than 0.3 in the better eye but improved by at least 0.2 LogMAR after correction. Controls were individuals in whom the difference between the presenting and corrected vision was less than 0.2 LogMAR. The prevalence of the unmet need was 5.7 % and it was more prevalent in women (6.5 %) than in men (4.6 %) (p = 0.003). There was a gap of 19.6 % between the two groups of high and low economic status. The Oaxaca-Blinder decomposition method revealed that differences in the education level of the two groups accounted for half of this gap. Spectacle usage is better in Iran than in some other developing countries; however, in this study, about 40 % of those who required spectacles did not have them.

Six year Trend in Cataract Surgical Techniques in Iran

Purpose

To determine the cataract surgery techniques performed in Iran from 2000 to 2005.

Materials and Methods

This study was part of the Iranian Cataract Surgery Survey (ICSS) which was a retrospective cross-sectional study. All major ocular surgery units and 10% of randomly selected minor units throughout Iran were included. Excluding the 2 week Iranian New Year holiday, 1 week per season between 2000 and 2005 (a total of 24 weeks) was selected for each center, and data on all cataract surgeries performed during these weeks were collected by reviewing patient records. The ANOVA repeated measure test was performed to determine longitudinal changes with a P<0.05 denoting statistical significance.

Results

Phacoemulsification with intraocular lens (IOL) implantation has become the surgical method of choice in Iran, increasing from less than 7% in 2000 to 57% in 2005 (P<0.0001). Extracapsular cataract extraction showed a reverse trend compared to phacoemulsification, decreasing from greater than 91% in 2000 to 41% in 2005 (P<0.0001). Intracapsular cataract extraction and lensectomy were rarely performed without significant changes over time (P>0.05).

Conclusion

Phacoemulsification with IOL implantation has become the preferred cataract surgery method in Iran during recent years.

Uncorrected refractive error in a Latino population: proyecto VER

PURPOSE

To determine the prevalence of refractive error (RE), the proportion of those with uncorrected RE, and factors associated with uncorrected RE in Latino adults.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

A random sample of 4509 Latinos aged ≥40 years from Arizona with both ophthalmic evaluation and questionnaire.

METHODS

A case of RE was defined as a subject wearing prescription glasses for distance vision whose presenting visual acuity (PVA) was ≥20/25, or a subject with PVA <20/25 in at least 1 eye who improved ≥2 lines after subjective refraction and whose refractive correction met these cutoffs: sphere < -0.5 diopters (D) or >1.0 D or cylinder ≥ +1.0 D. Among those with RE, those who on refraction achieved ≥2 line improvement in at least 1 eye (definition 1) or in both eyes (definition 2) were classified as uncorrected RE. A questionnaire on access to care, acculturation, and socioeconomic variables was used.

MAIN OUTCOME MEASURES

Prevalence of RE and proportion of uncorrected RE.

RESULTS

The prevalence of RE was 64% in at least 1 eye and 51% in both eyes. Of participants with RE in at least 1 eye, 35% have uncorrected RE. Of those with RE in both eyes, 19% have uncorrected RE. Compared with participants with corrected RE, those with uncorrected RE in at least 1 eye were more likely to have lower levels of acculturation (odds ratio [OR] 1.2; 95% confidence interval [CI], 1.1-1.4 per unit decrease) and education (OR 1.6 for ≤6 years vs. >12 years; 95% CI, 1.2-2.2). Uncorrected RE was also associated with not having insurance (OR 1.4; 95% CI, 1.1-1.6), with a low family income (OR 1.4; 95% CI, 1.1-1.7 for <$20,000/year), and with time since last health care visit (OR 1.4; 95% CI, 1.1-1.7 for >1 year vs. <6 months).

CONCLUSIONS

In our sample of Latinos, the proportion of uncorrected RE is high and suggests that one third of those with RE may benefit from new glasses. Indices of marginalization are associated with uncorrected RE and could be targeted for future interventions.

Frequency, course, and impact of correctable visual impairment (uncorrected refractive error)

Uncorrected refractive error has been identified by the World Health Organization (WHO) as one of the priorities for Vision 2020 and a frequent cause of visual impairment. In the past, only the terms presenting visual impairment (PVI) and visual impairment after best refractive correction (BCVI) were used, so that PVI also included BCVI cases. In the more recent literature, visual impairment has been subdivided into two mutually exclusive entities: that which is correctable by refraction (which we now term correctable visual impairment, CVI) and that which cannot be corrected by refraction due to ocular or neurological disease (which we now term non-correctable visual impairment, NCVI, and which is identical to BCVI). PVI remains a useful concept as it includes both types of impairment. Although CVI is reported to be the major form of visual impairment worldwide, its impacts are not yet well understood. CVI has a higher prevalence among vulnerable groups such as older people, less well educated people and those living alone or in rural areas. Systematic data on barriers to refractive correction remain scant, but these may be present at the individual level, within the health service context, or at a social level. Our review indicates that research on CVI is at a relatively early stage and that more detailed research, particularly determining whether it has impacts on independent living and quality of life, is needed before CVI can be justifiably prioritized in health policy.

The prevalence and risk indicators of uncorrected refractive error and unmet refractive need in Latinos: the Los AngelesLatino Eye Study

PURPOSE

To determine the age- and sex-specific prevalence and risk indicators of uncorrected refractive error and unmet refractive need among a population-based sample of Latino adults.

METHODS

Self-identified Latinos 40 years of age and older (n = 6129) from six census tracts in La Puente, California, underwent a complete ophthalmic examination, and a home-administered questionnaire provided self-reported data on potential risk indicators. Uncorrected refractive error was defined as a >or=2-line improvement with refraction in the better seeing eye. Unmet refractive need was defined as having <20/40 visual acuity in the better seeing eye and achieving >or=20/40 after refraction (definition 1) or having <20/40 visual acuity in the better seeing eye and achieving a >or=2-line improvement with refraction (definition 2). Sex- and age-specific prevalence and significant risk indicators for uncorrected refractive error and unmet refractive need were calculated.

RESULTS

The overall prevalence of uncorrected refractive error was 15.1% (n = 926). The overall prevalence of unmet refractive need was 8.9% (n = 213, definition 1) and 9.6% (n = 218, definition 2). The prevalence of uncorrected refractive error and either definition of unmet refractive need increased with age (P < 0.0001). No sex-related difference was present. Older age, <12 years of education, and lack of health insurance were significant independent risk indicators for uncorrected refractive error and unmet refractive need.

CONCLUSIONS

The data suggest that the prevalence of uncorrected refractive error and unmet refractive need is high in Latinos of primarily Mexican ancestry. Better education and access to care in older Latinos are likely to decrease the burden of uncorrected refractive error in Latinos.

Age-specific changes in the prevalence and management of optically correctable visual impairment between 1988 and 2000: the Ponza Eye Study

PURPOSE

To obtain age-specific data on changes in the prevalence and management of optically correctable visual impairments (OCVIs) in Ponza, Italy.

METHODS

Ophthalmologic examinations were carried out to 1000 Ponzans aged 40-87 years in 1988 and to 836 persons in 2000. Visual acuity (VA) was evaluated under uncorrected (VA(UC)), presenting (VA(PR)), and best-corrected (VA(BC)) conditions. We calculated the prevalence of total OCVIs (subjects with VA(UC)>0.5 logMAR and VA(BC)<or=0.5 logMAR in the better eye), uncorrected OCVIs (VA(PR)>0.5 logMAR), and corrected OCVIs (VA(PR)<or=0.5 logMAR) as well as the OCVI correction rate ((corrected OCVI/total OCVI) x 100). Subjects with uncorrected OCVIs were compared to those with corrected OCVIs to evaluate possible associations with some risk factors.

RESULTS

Among 52- to 63-year olds there were increases in the prevalence of total OCVI (from 15.7 to 22.7%, P=0.051), corrected OCVI (from 10.9 to 19.9%, P=0.005), and OCVI correction rate (from 69.2 to 87.8%, P=0.045). Among 64- to 75-year olds decreases were observed in the prevalence of total OCVI (from 28.5 to 20.0%, P=0.029) and uncorrected OCVI (from 12.6 to 4.8%, P=0.003) while the OCVI correction rate increased from 55.9 to 76.1% (P=0.033). The overall prevalence of uncorrected OCVIs dropped from 7.5 to 4.1%. In 2000, uncorrected OCVI was associated with limited education, very advanced age, retirement, and refractive error associated with eye diseases.

CONCLUSIONS

Refractive error management has improved in Ponza since 1988, and these changes may be, in part, due to higher education levels, increased frequency of cataract surgery, and slower progression of cataract-related disability.

Correction of refractive error and presbyopia in Timor-Leste

AIM

To investigate the aspects of spectacle correction of vision-impairing refractive error and presbyopia in those aged >or=40 years in Timor-Leste.

METHOD

A population-based cross-sectional survey with cluster random sampling was used to select 50 clusters of 30 people. Those who had uncorrected or undercorrected refractive error (presenting acuity worse than 6/18, but at least 6/18 with pinhole), uncorrected or undercorrected presbyopia (near vision worse than N8), and/or who were using or had used spectacles were identified. Dispensing history, willingness to wear and willingness to pay for spectacles were elicited.

RESULTS

Of 1470 people enumerated, 1414 were examined (96.2%). The "met refractive error need" in the sample was 2.2%, and the "unmet refractive error need" was 11.7%. The "refractive error correction coverage" was 15.7%. The "met presbyopic need" was 11.5%, and the "unmet presbyopic need" was 32.3%. The "presbyopia correction coverage" was 26.2%. Lower correction coverage was associated with rural domicile, illiteracy and farming. Of the sample, 96.0% were willing to wear spectacles correcting impaired vision. Of these, 17.0% were willing to pay US$3 ( pound 1.52, euro 2.24) for spectacles, whereas 50.2% were unwilling to pay US$1 ( pound 0.51, euro 0.75). Women and rural dwellers were less likely to be willing to pay at least US$1 for spectacles.

CONCLUSION

Refractive error and presbyopia correction coverage rates are low in Timor-Leste. There is a large need for spectacles, especially for elderly and illiterate people, farmers and rural dwellers: those least able to pay for them. An equitable cross-subsidisation spectacle system should be possible.

Capturing myopia and hypermetropia ‘phenotypes’ without formal refraction

PURPOSE

Understanding genetic and environmental factors that together contribute to the development of myopia is an international research priority. We have investigated the feasibility and accuracy of identifying and classifying refractive error, without formal refraction, as a means of easily identifying affected individuals in a large-scale, non-ophthalmological, and population-based survey.

METHODS

At age 44/45 years, members of the 1958 British birth cohort underwent a biomedical, community survey. Refractive error (autorefraction) was measured and categorised by spherical equivalent (SE) measurement; myopia (SE of -1.00 or more extreme), hypermetropia (+1.00 or more extreme), or emmetropia (-0.99 to +0.99). Lenses of prescribed distance glasses, if worn, were assessed as minifying, magnifying, or making no difference to a standard viewed image and cohort members reported on 'short' or 'long' sightedness.

RESULTS

A total of 2499 cohort members, randomly selected, had formal refraction (autorefraction) and 917 (36.7%) of these individuals had their prescribed distance glasses examined. Sensitivities for myopia and hypermetropia using examination of glasses were over 80% and positive predictive values were 95 and 65% respectively whereas self-report of 'short-sightedness' or 'long-sightedness' had poor accuracy.

CONCLUSION

We suggest examination of prescribed distance glasses can be an effective method of 'screening' for refractive error in the field, especially where prevalence is high.