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

Uncorrected Refractive Error in the African American Eye Disease Study

Importance

Refractive error remains the largest cause of correctable visual impairment in the US. Correction of refractive error will reduce visual impairment and its associated morbidity but also improve quality of life and productivity.

Objective

To determine the burden of and risk factors (RFs) associated with any uncorrected refractive error (UCRE) and unmet refractive need (URN) in a population-based sample of African American adults.

Design, Setting, and Participants

This cross-sectional study, conducted from April 2014 to April 2018, included a population-based sample of self-identified African American participants 40 years and older from 30 contiguous census tracts in Inglewood, California. Participants underwent a complete ophthalmic examination and an in-home-administered questionnaire to assess sociodemographic, lifestyle, biological, medical, and health care and eye care usage RFs associated with UCRE and URN. Measurements of visual acuity (VA) were performed using a standard Early Treatment Diabetic Retinopathy Study protocol. Noncycloplegic automated refraction with supplemental subjective refraction was performed. UCRE was defined as an improvement of 2 or more lines with refraction in the better-seeing eye. URN was defined as an improvement of 2 or more lines with refraction in the better-seeing eye in those persons who were visually impaired. Sex- and age-specific burden of UCRE and URN were calculated, and multiple regression analyses were used to identify independent RFs. Study data were analyzed from May 2018 to December 2023.

Exposures

Presence or absence of correctable refractive error.

Main Outcomes and Measures

Self-reported sex- and age-specific prevalence of and risk indicators of UCRE and URN.

Results

Of the 7957 eligible participants in the African American Eye Disease Study (AFEDS), 6347 (80%) completed both the in-home interview and the clinical examination. Of these, 6337 participants (mean [SD] age, 61 [11] years; 3997 female [63%]) with complete refractive error data were included in the analysis. Refractive error-related correctable visual impairment was present in over two-thirds of participants with visual impairment (68.7%). The overall prevalence of any UCRE was 14.6% (925 of 6337), and the overall prevalence of any URN was 5.4% (URN1 [those with presenting VA of worse than 20/40 in the better-seeing eye but who could achieve 20/40 or better with correction], 157 of 2893; URN2 [those with presenting VA of worse than 20/40 in the better-seeing eye but who could achieve an improvement of 2 or more lines with refractive correction], 155 of 2891).

Conclusions and Relevance

Results of this cross-sectional study suggest a high burden of refractive error-associated correctable refractive error in African American adults, making it the leading cause of visual impairment in this population. Providing universal coverage for vision care and prescription glasses is an affordable and achievable health care intervention that could reduce the burden of visual impairment in African American adults by over two-thirds and likely raise the quality of life and work productivity, especially in this vulnerable minority population.

Visual Impairment from Uncorrected Refractive Error among Participants in a Novel Program to Improve Eye Care Access among Low-Income Adults in Michigan

PURPOSE

To assess the rate of visual impairment (VI) from uncorrected refractive error (URE) and associations with demographic and socioeconomic factors among low-income patients presenting to the Michigan Screening and Intervention for Glaucoma and Eye Health through Telemedicine (MI-SIGHT) program.

DESIGN

Cross-sectional study.

PARTICIPANTS

Adults ≥ 18 years without acute ocular symptoms.

METHODS

MI-SIGHT program participants received a telemedicine-based eye disease screening and ordered glasses through an online optical store. Participants were categorized based on refractive error (RE) status: VI from URE (presenting visual acuity [PVA], ≤ 20/50; best-corrected visual acuity [BCVA], ≥ 20/40), URE without VI (PVA, ≥ 20/40; ≥ 2-line improvement to BCVA), and no or adequately corrected RE (PVA, ≥ 20/40; < 2-line improvement to BCVA). Patient demographics, self-reported visual function, and satisfaction with glasses obtained through the program were compared among groups using analysis of variance, Kruskal-Wallis, chi-square, and Fisher exact testing.

MAIN OUTCOME MEASURES

PVA, BCVA, and presence of VI (defined as PVA ≤ 20/50).

RESULTS

Of 1171 participants enrolled in the MI-SIGHT program during the first year, average age was 55.1 years (SD = 14.5), 37.7% were male, 54.1% identified as Black, and 1166 (99.6%) had both PVA and BCVA measured. VI was observed in 120 participants (10.3%); 96 had VI from URE (8.2%), 168 participants (14.4%) had URE without VI, and 878 (75.3%) had no or adequately corrected RE. A smaller percentage of participants with VI resulting from URE reported having a college degree, and a larger percentage reported income < $10 000 compared with participants with no or adequately corrected RE (3.2% vs. 14.2% [P = 0.02]; 45.5% vs. 21.6% [P < 0.0001], respectively). Visual function was lowest among participants with VI from URE, followed by those with URE without VI, and then those with no or adequately corrected RE (9-item National Eye Institute Visual Function Questionnaire composite score, 67.3 ± 19.6 vs. 77.0 ± 14.4 vs. 82.2 ± 13.3, respectively; P < 0.0001). In total, 71.2% (n = 830) ordered glasses for an average cost of $36.80 ± $32.60; 97.7% were satisfied with their glasses.

CONCLUSIONS

URE was the main cause of VI at 2 clinics serving low-income communities and was associated with reduced vision-related quality of life. An online optical store with lower prices made eyeglasses accessible to low-income patients.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Vision Need Profiles for the City of Richmond, Virginia: A Pilot Application of Calibration Methods to Vision Surveillance

Purpose

People with vision problems (VPs) have different needs based on their age, economic resources, housing type, neighborhood, and other disabilities. We used calibration methods to create synthetic data to estimate census tract-level community need profiles (CNPs) for the city of Richmond, Virginia.

Design

Cross-sectional secondary data analysis.

Subjects

Anonymized respondents to the 2015 to 2019 American Community Survey (ACS).

Methods

We used calibration methods to transform the ACS 5-year tabular (2015-2019) and Public Use Microdata estimates into a synthetic data set of person-level records in each census tract, and subset the data to persons who answered yes to the question "Are you blind or do you have serious difficulty seeing even when wearing glasses?" To identify individual need profiles (INPs), we applied divisive clustering to 17 variables measuring individual demographics, nonvision disability status, socioeconomic status (SES), housing, and access and independence. We labeled tracts with CNP names based on their predominant INPs and performed sensitivity analyses. We mapped the CNPs and overlayed information on the number of people with VP, the National Walkability Index, and an uncertainty measure based on our sensitivity analysis.

Main Outcome Measures

Individual need profiles and CNPs.

Results

Compared with people without VP, people with VP exhibited higher rates of disabilities, having low incomes, living alone, and lacking access to the internet or private home vehicles. Among people with VP, we identified 7 INP clusters which we mapped into 6 CNPs: (1) seniors (≥ age 65); (2) low SES younger; (3) low SES older; (4) mixed SES; (5) higher SES; and (6) adults and children in group quarters. Three CNPs had lower-than-average walkability. Community need profile assignments were somewhat sensitive to calibration variables, with 18 tracts changing assignments in 1 sensitivity analysis, and 4 tracts changing assignments in ≥ 2 sensitivity analyses.

Conclusions

This pilot project illustrates the feasibility of using ACS data to better understand the support and service needs of people with VP at the census tract level. However, a subset of categorical CNP assignments were sensitive to variable selection leading to uncertainty in CNP assignment in certain tracts.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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.

Pediatric Eye Care Treatment Rates and Community Compliance to a Spectacle Provision Program in an Underserved School District in San Diego, CA

Significance

The need for early identification and treatment of young children's refractive error needs has become a public health concern. The UCSD Eyemobile for Children (EyeMobile) provides vision screenings and comprehensive eye exams on the Eyemobile among a population of underserved, predominantly Hispanic preschool and elementary school children. The program also provides spectacles for children who fail eye exams due to refractive error.

Methods

We performed a retrospective cross-sectional analysis of all children screened from 2011 to 2017 by the Eyemobile across 10 San Diego elementary schools. We examined demographics, distance and near visual acuity, autorefraction, stereopsis, and color vision. To measure compliance to our spectacle program, we checked if children who were prescribed spectacles were wearing them, as instructed, at the following year's screening. Differences between compliance measures with respect to school, age, ethnicity, and gender were determined using chi-square analysis, while all other measures were fit to a binary logistic regression to determine statistically significant factors.

Results

A total of 12,176 elementary school children were screened between 2011 and 2017. Of these children, 5269 (43.3%) were referred for a comprehensive eye examination. Across six years, 3163 (60.0%) of the children referred completed their eye examinations. There was a significant increase (p < 0.001) in exam completion in the successive years. Exam completion was significantly higher in ten-year-olds (p = 0.0278) and in 3 of the 10 schools (p < 0.0001, p = 0.0027, and p = 0.0309). A total of 1089 (8.9% of screened) children were prescribed spectacles. Of the 409 children that were recorded with the compliance method, 342 (83.6%) were found to be fully compliant and wearing their spectacles as prescribed.

Conclusion

The Eyemobile program demonstrated high levels of compliance for both eye examination completion and prescribed spectacle wear in underserved populations in the San Diego region, compared to similar national programs.

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 of uncorrected refractive error in Japan: the Locomotive Syndrome and Health Outcome in Aizu Cohort Study

PURPOSE

Uncorrected refractive error (URE) is the leading cause of vision impairment and the second leading cause of blindness. It is a major public health challenge worldwide. However, the current status of URE in Japan is unclear.

STUDY DESIGN

Cross-sectional study.

METHODS

In 2012, a population-based cross-sectional study was conducted among community dwellers aged 40 years and older who received health check-ups in Minamiaizu and Tadami, Fukushima Prefecture, Japan. URE was considered when the presenting visual acuity in the better-seeing eye was < 0.5 and when visual acuity improved more than 1 line with refractive correction in the better-seeing eye. We estimated the age-specific prevalence of URE, and calculated the p-value for trend to examine the linear pattern of the association of the prevalence of URE and age.

RESULTS

This analysis included 2952 participants. The mean age (standard deviation [SD]) of the study population was 69.10(9.67) years and 57.79% were women. The overall prevalence of URE was 10.90% (95% CI, 9.77-12.05%). Prevalence by age category was 5.00% (95% CI, 2.03-10.03%), 6.09% (95% CI, 3.59-9.58%), 7.02% (95% CI, 5.49-8.81%), 11.96% (95% CI, 10.15-13.97%), and 22.39% (95% CI, 18.41-26.78%) for 40-49 years, 50-59 years, 60-69 years, 70-79 years, and 80 years or older, respectively (p-for trend, < 0.001).

CONCLUSIONS

The prevalence of URE was 10.9% and exceeded 20%, especially in individuals older than 80 years. Given the correlation between increasing incidence of URE and increase in age, public health intervention to promote awareness of URE is important, especially for the older population.

Refractive Error of Students (15- to 18-year-olds) in Northwest Mexico

SIGNIFICANCE

We assessed the prevalence of refractive error in a sample of children of Northern Mexico using the Refractive Error Study in Children protocol of the World Health Organization, which allows for the comparison with other global studies.

PURPOSE

Uncorrected refractive error is the main cause of visual impairment in children. The purpose of this study was to assess the refractive error and visual dysfunctions of students (15 to 18 years old) in the upper-middle school system of Sinaloa, Mexico.

METHODS

A total of 3468 students in Sinaloa's high school system participated in the study from 2017 to 2019. Optometrists and student clinicians from the Optometry Program of the Autonomous University of Sinaloa conducted the testing. Tests included visual acuities and static retinoscopy. We did not use a cycloplegic agent.

RESULTS

The results showed a high prevalence of uncorrected refractive errors. Myopia, defined as a refractive error ≤-0.50 D, had a prevalence of 36.11% (95% confidence interval, 33.47 to 38.83%); hyperopia, defined as a refractive error ≥+2.00 D, had a prevalence of 1.49% (95% confidence interval, 0.09 to 2.33%); and astigmatism, defined as a refractive error with a cylinder ≥0.75 D, had a prevalence of 29.17% (95% confidence interval, 26.60 to 31.76%). We found a significant effect of sex on visual acuity.

CONCLUSIONS

Our results are consistent with a high prevalence of myopia reported in adolescents worldwide and in Mexico's northern regions. The results suggest that students attending high school and entering universities should be required to have an optometric eye examination. Additional studies are needed to investigate the prevalence of refractive errors in children in Mexico.

The prevalence and correlates of vision impairment and glasses ownership among ethnic minority and Han schoolchildren in rural China

PURPOSE

To determine the prevalence of visual impairment and glasses ownership among Han Chinese and Hui minority junior high school children in Ningxia Hui Autonomous Region, China.

DESIGN

Population-based cross-sectional study.

METHODS

Vision screening was conducted on 20,376 children (age 12-15 years) in all 124 rural junior high schools in Ningxia. Personal and family characteristics, glasses ownership, and academic performance were assessed through a survey questionnaire and standardized mathematics test, respectively.

RESULTS

The prevalence of visual acuity (VA) ≤6/12 in either eye was significantly higher among Han (54.5%) than Hui (45.2%) children (P<0.001), and was significantly positively associated with age, female sex, Han ethnicity, parental outmigration for work, shorter time spent outside during recess, shorter time spent watching television and higher time spent studying. Among children with VA≤6/12 in both eyes, only 56.8% of Han and 41.5% of Hui children had glasses (P<0.001). Glasses ownership was significantly associated with worse vision, greater family wealth, female sex, higher test scores, age, parental outmigration for work, understanding of myopia and glasses, higher time spent studying and Han ethnicity.

CONCLUSION

One of the first of its kind, this report on Han and Hui ethnic schoolchildren confirms a high prevalence of visual impairment among both populations, but slightly higher among the Han. Both groups, especially the Hui, have low rates of glasses ownership. Future interventions and policies designed to improve glasses usage should focus on populations with lower incomes and seek to correct erroneous beliefs about the safety of glasses and efficacy of traditional eye exercises.

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.

Incidence of visual impairment in Canada: The Canadian Longitudinal Study on Aging

OBJECTIVE

Determine the 3-year incidence of visual impairment (VI) in Canada and its risk factors.

DESIGN

Prospective 3-year cohort study PARTICIPANTS: Data from 23 973 adults taking part in the Canadian Longitudinal Study on Aging Comprehensive Cohort baseline and 3-year follow-up exams were included.

METHODS

Inclusion criteria were 45 to 85 years of age, community-dwelling, and living near one of the 11 data collection sites across 7 Canadian provinces. Presenting binocular visual acuity was measured using the Early Treatment of Diabetic Retinopathy study chart. Incidence of VI was defined as the development at follow-up of visual acuity worse than 20/40 in those with acuity better than or equal to 20/40 at baseline.

RESULTS

3.88% (95% confidence interval [CI] 3.61-4.17) of Canadian adults developed VI over a 3-year period. There was a high degree of variability in the incidence between Canadian provinces with a low of 1.42% in Manitoba and a high of 7.33% in Nova Scotia. Uncorrected refractive error was the leading cause. Risk factors for incident VI included older age (odds ratio [OR] = 1.07, 95% CI 1.06-1.07), Black race (OR = 2.64, 95% CI 1.36-5.14), lower household income (OR = 1.73 for those making less than $20,000 per year, 95% CI 1.24-2.40), current smoker (OR = 1.78, 95% CI 1.37-2.32), and province.

CONCLUSION

The incidence of visual impairment is common in older Canadian adults, varies markedly between provinces, and is largely owing to treatable causes. Risk factors for VI suggest subgroups that may benefit from interventions to improve access to eye care.

The Vision Detroit Project: Visual Burden, Barriers, and Access to Eye Care in an Urban Setting

Purpose: Vision loss and blindness are among the top ten disabilities in the United States, yet access and utilization of eye care remains low. Vision Detroit aimed to address eye-care disparities via community-based screenings. By investigating burden of eye disease and barriers to eye-care utilization in an underserved urban community, we may direct efforts to improve access.Methods: Twenty-three screenings were conducted from March 2015-November 2017. Patient information gathered at screenings were demographics, medical and social history, eye exam/referral history, insurance status, primary care physician (PCP) status, and patient-perceived eye-care barriers.Results: Three-hundred-eighty patients were screened, 42% African American and 51% Hispanic. Average age was 53 ± 16.4 years, 70% reported vision problems, 50% reported over two years of vision problems, and average habitual visual acuity in best-seeing eye was 20/37. Eye-care underutilization was reported in 61% of type-2 diabetics. Older age and PCP recommendations/referrals were associated with increased utilization in all patients. Insurance was the most common barrier (53%); of the 55% insured, 31% reported financial barriers. Employed patients were more likely than unemployed to report a time barrier (odds ratio = 1.76, 95% confidence interval 1.03-3.01). Those with high school or less education reported "unaware of need", "unsure where to go", "transportation", and "insurance" as barriers more often.Conclusions: Visual burden was pervasive, yet access was suboptimal. Financial, logistical, and awareness barriers were common. PCP referral and older age were associated with increased utilization. Those less educated reported more barriers, highlighting the need to address fiscal concerns and eye-health education.

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.

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.

Prevalence and Associated Factors of Uncorrected Refractive Error in Older Adults in a Population-Based Study in France

Importance

Uncorrected refractive error (URE) is a common cause of visual impairment, but its prevalence in groups of older adults who could be pragmatic targets for improving optical correction remains unknown.

Objectives

To estimate the prevalence of URE in older adults, particularly in those with age-related eye disease and those who are unable to attend an outpatient clinic, and to identify the factors associated with URE.

Design, Setting, and Participants

This population-based cross-sectional analysis included 707 adults 78 years or older from the Alienor Study in Bordeaux, France. Data were collected from February 12, 2011, through December 21, 2012, and analyzed from November 1, 2017, through July 7, 2018.

Main Outcomes and Measures

Uncorrected refractive error was defined as the presenting distance visual acuity in the better-seeing eye improved by at least 5 letters on the Early Treatment Diabetic Retinopathy Study chart (≥1 line on the logMAR chart) using the best-achieved optical correction. Multivariate logistic regressions were used to determine the factors associated with URE.

Results

The study population of 707 adults 78 years or older (64.8% women; mean [SD] age, 84.3 [4.4] years) had a prevalence of URE of 38.8% (95% CI, 35.2%-42.5%). Prevalence was high for participants with eye disease (range, 35.0% [95% CI, 28.4%-42.0%] to 44.1% [95% CI, 27.2%-62.1%], depending on the disease) and those without eye disease (30.1%; 95% CI, 24.0%-36.7%). Prevalence was higher in participants who were examined at home (because they could not come to the clinic) than in those examined at the clinic (49.4% [95% CI, 42.8%-55.9%] vs 33.5% [95% CI, 29.2%-37.9%]; P < .001). Having an eye examination performed at home (odds ratio [OR], 1.64; 95% CI, 1.13-2.37), living alone (OR, 0.65; 95% CI, 0.47-0.90), and having the perceptions that the ophthalmologist consultation fees are too expensive (OR, 1.94; 95% CI, 1.12-3.36) and that declining visual acuity is normal with aging (OR, 1.47; 95% CI, 1.04-2.08) were all associated with URE.

Conclusions and Relevance

These study results show that the prevalence of URE was high in this population and suggest that preventive strategies aimed at enhancing optical correction could be directed to all older adults and to specific groups by implementing at-home eye examinations for those who have difficulties attending an outpatient clinic and by focusing on those with eye disease who probably already have a regular ophthalmologic follow-up. More studies are needed to evaluate prevalence of URE in different populations and countries with various eye care systems.

eHealth tools for the self-testing of visual acuity: a scoping review

Uncorrected refractive error is a major cause of vision impairment, and is indexed by visual acuity. Availability of vision assessment is limited in low/middle-income countries and in minority groups in high income countries. eHealth tools offer a solution; two-thirds of the globe own mobile devices. This is a scoping review of the number and quality of tools for self-testing visual acuity. Software applications intended for professional clinical use were excluded. Keyword searches were conducted on Google online, Google Play and iOS store. The first 100 hits in each search were screened against inclusion criteria. After screening, 42 tools were reviewed. Tools assessed near and distance vision. About half (n = 20) used bespoke optotypes. The majority (n = 25) presented optotypes one by one. Four included a calibration procedure. Only one tool was validated against gold standard measures. Many self-test tools have been published, but lack validation. There is a need for regulation of tools for the self-testing of visual acuity to reduce potential risk or confusion to users.

Ophthalmologic health status of an aging population-data from the Berlin Aging Study II (BASE-II)

PURPOSE

Vision of the elderly may be affected by typical age-related diseases like cataract and macular degeneration. Little is known about the effect of aging on visual difficulties and vision-related quality of life. This study was conducted to compare the ophthalmological health status of younger and older individuals within a large cohort study of residents of a greater metropolitan area (Berlin Aging Study II [BASE-II]).

METHODS

A total of 1655 participants (805 men) aged 60 years and older and 494 participants (232 men) aged between 22 and 48 years from the Berlin Aging Study II were included in the analysis. The subjects were examined during a 2-day clinical examination period. History of ocular diseases, vision-related quality of life using the visual function questionnaire (VFQ- 25), refraction, distance and near visual acuity, tonometry, and color vision were provided.

RESULTS

Older subjects performed significantly worse concerning distance and near visual acuity, color vision, and vision-related quality of life compared to young subjects. Intraocular pressure showed no significant difference between groups. Individuals are often unaware of existing eye diseases.

CONCLUSION

The prevalence of ocular diseases and the impairment of vision increases with age. Although 98% of elderly subjects have reported to suffer from any ocular disease, subjective quality of life seems to be affected to a lesser extent.

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.

Differences in Eye Health, Access to Eye Care Specialists and Use of Lenses among Immigrant and Native-Born Workers in Spain

Latin American immigrants make up 49% of the total immigrant population in Spain, yet little is known about their eye health. The aim of this study is to determine if there are differences in self-perceived eye health, access to eye care specialists, and use of lenses between a sample of Latin American immigrant workers from Colombia and Ecuador, and native-born workers in Spain. We used data from the PELFI cohort (Project for Longitudinal Studies of Immigrant Families). The sample consisted of 179 immigrant workers born in Colombia or Ecuador, and 83 Spanish-born workers. The outcome variables were self-perceived eye health, access to eye specialists, and use of lenses. A descriptive analysis of the sample was carried out, and the prevalence of the three outcome variables in immigrants and natives was calculated and adjusted for explanatory variables. Random effects logistic regression models examined eye health outcomes by workers’ country of birth. Immigrants are less likely to report poor self-perceived eye health than native-born (ORc 0.46; CI 95%, 0.22–0.96). Furthermore, they have less access to specialists (ORc 2.61; CI 95%, 1.32–5.15) and a higher probability of needing lenses but not having them (ORc 14.14; CI 95%, 1.77–112.69). This latter variable remained statistically significant after adjusting for covariates (ORa 34.05; CI 95%, 1.59–729.04). Latin American immigrants may not value the use of lenses, despite eye care specialists indicating that they need them. Eye health education is required to recognize the importance of using lenses according to their visual needs.

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.

Fundamentals of Presbyopia: visual processing and binocularity in its transformation

Background

The accommodation has considerable interactions with the pupil response, vergence response and binocularity. The transformation of visual reception processing and the changes of the binocular cooperation during the presbyopia development are still poorly studied. So, the regularities of visual system violation in the presbyopia formation need to be characterized. This study aims to reveal the transformation of visual reception processing and to determine the role of disturbances in binocular interactions in presbyopia formation.

Methods

This study included 60 people with emmetropic refraction, uncorrected distance visual acuity 1.0 or higher (decimal scale), normal color perception, without concomitant ophthalmopathology. The first group consisted of 30 people (from 18 to 27 years old) without presbyopia, the second cohort comprised 30 patients (from 45 to 55 years old) with presbyopia. The eyeball anatomy and optics were evaluated using ultrasound biomicroscopy, aberrometry, and pupillometry. The functional state of the visual system was investigated under monocular and binocular conditions. The registration of the disparate fusional reflex limits was performed by the original technic using a diploptic device which facilitated investigation of the binocular interaction under natural conditions without the accommodation response, but with the different vergence load. The disparate fusional reflex was analyzed using the proximal and distal fusion borders, and the convergence and divergence fusion borders. The calculation of the area of binocularity field was performed in cm².

Results

The presbyopia formation is characterized by a change in an intraocular anatomy, optics, visual processing, and binocularity. The processes of binocular interaction inhibition make a significant contribution to the misalignment of the visual perception. The modification of the proximal, distal and convergence fusion borders was determined. It was revealed that 87% of the presbyopic patients had binocularity shortage, whereas the reduction of binocularity field area in extreme grade was seen in 6% of cases.

Conclusions

The presbyopia formation is accompanied by a significant reorganization of the visual system activity and by the creation of the new visual processing interactions. These data may be useful in presbyopia surgery.

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.

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.

Refractive errors among children, adolescents and adults attending eye clinics in Mexico

AIM

To assess the proportion of refractive errors in the Mexican population that visited primary care optometry clinics in fourteen states of Mexico.

METHODS

Refractive data from 676 856 patients aged 6 to 90y were collected from optometry clinics in fourteen states of Mexico between 2014 and 2015. The refractive errors were classified by the spherical equivalent (SE), as follows: sphere+½ cylinder. Myopia (SE>-0.50 D), hyperopia (SE>+0.50 D), emmetropia (-0.50≤SE≤+0.50), and astigmatism alone (cylinder≥-0.25 D). A negative cylinder was selected as a notation.

RESULTS

The proportion (95% confidence interval) among all of the subjects was hyperopia 21.0% (20.9-21.0), emmetropia 40.7% (40.5-40.8), myopia 24.8% (24.7-24.9) and astigmatism alone 13.5% (13.4-13.5). Myopia was the most common refractive error and frequency seemed to increase among the young population (10 to 29 years old), however, hyperopia increased among the aging population (40 to 79 years old), and astigmatism alone showed a decreasing trend with age (6 to 90y; from 19.7% to 10.8%). There was a relationship between age and all refractive errors (approximately 60%, aged 50 and older). The proportion of any clinically important refractive error was higher in males (61.2%) than in females (58.3%; P<0.0001). From fourteen states that collected information, the proportion of refractive error showed variability in different geographical areas of Mexico.

CONCLUSION

Myopia is the most common refractive error in the population studied. This study provides the first data on refractive error in Mexico. Further programs and studies must be developed to address the refractive errors needs of the Mexican population.

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.

Visual Impairment in White, Chinese, Black, and Hispanic Participants from the Multi-Ethnic Study of Atherosclerosis Cohort

PURPOSE

To describe the prevalence of visual impairment and examine its association with demographic, socioeconomic, and health characteristics in the Multi-Ethnic Study of Atherosclerosis (MESA) cohort.

METHODS

Visual acuity data were obtained from 6134 participants, aged 46-87 years at time of examination between 2002 and 2004 (mean age 64 years, 47.6% male), from six communities in the United States. Visual impairment was defined as presenting visual acuity 20/50 or worse in the better-seeing eye. Risk factors were included in multivariable logistic regression models to determine their impact on visual impairment for men and women in each racial/ethnic group.

RESULTS

Among all participants, 6.6% (n = 421) had visual impairment, including 5.6% of men (n = 178) and 7.5% of women (n = 243). Prevalence of impairment ranged from 4.2% (n = 52) and 6.0% (n = 77) in white men and women, respectively, to 7.6% (n = 37) and 11.6% (n = 44) in Chinese men and women, respectively. Older age was significantly associated with visual impairment in both men and women, particularly in those with lower socioeconomic status, but the effects of increasing age were more pronounced in men. Two-thirds of participants already wore distance correction, and not unexpectedly, a lower prevalence of visual impairment was seen in this group; however, 2.4% of men and 3.5% of women with current distance correction had correctable visual impairment, most notably among seniors.

CONCLUSION

Even in the U.S. where prevalence of refractive correction is high, both visual impairment and uncorrected refractive error represent current public health challenges.

Factors Associated With Ocular Health Care Utilization Among Hispanics/Latinos: Results From an Ancillary Study to the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

IMPORTANCE

Regular ocular care is critical to early detection and prevention of eye disease and associated morbidity and mortality; however, there have been relatively few studies of ocular health care utilization among Hispanics/Latinos of diverse backgrounds.

OBJECTIVE

To examine factors associated with ocular health care utilization among Cuban, Central American, and South American Hispanics/Latinos in a cohort study.

DESIGN, SETTING, AND PARTICIPANTS

An ancillary study to the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) evaluating ocular health, knowledge, risk factors, and health care use was conducted with 1235 HCHS/SOL participants (aged ≥40 years) at the Miami, Florida, study site. Data were collected from October 17, 2011, to September 30, 2013, and analyses were conducted from May 28, 2014, to March 18, 2015. Descriptive and multivariable logistic regression analyses were performed for 3 ocular health care outcomes. Regression models were built sequentially with variables conceptually grouped according to Andersen's Behavioral Model of Health Services Use.

MAIN OUTCOMES AND MEASURES

Ever having an eye examination, having an eye examination performed within the past 2 years, and difficulty obtaining needed eye care in the past year.

RESULTS

Of the 1235 participants, 478 were men and 757 were women, and they had a mean (SD) age of 53.6 (8.1) years. Those who never had insurance were less likely to have had an eye examination (with data reported as odds ratios [95% CIs]) ever, 0.19 (0.07-0.53) and in the past 2 years, 0.22 (0.15-0.33) and were more likely to have had difficulty obtaining needed eye care in the past year (3.72 [1.75-7.93]). Those with less than excellent or good self-rated eyesight were less likely to ever have had an eye examination (0.26 [0.12-0.56]) and more likely to have had difficulty obtaining care (3.00 [1.48-6.11]). Men were less likely to ever have had an eye examination (0.31 [0.18-0.53]). Older (55-64 years) Hispanics/Latinos (3.04 [1.47-6.31]) and those with a high school degree or general educational development certification (2.06 [1.02-4.13]) or higher levels of education (4.20 [2.12-8.30]) were more likely to ever have had an eye examination. Finally, those living in the United States for more than 15 years (0.42 [0.21-0.82]) were less likely to have had difficulty obtaining care.

CONCLUSIONS AND RELEVANCE

Our findings suggest that increasing insurance coverage, decreasing the costs of care, and increasing the availability of care for Hispanics/Latinos with poor self-rated eyesight are relevant issues to address to improve ocular health care use among Hispanics/Latinos of diverse backgrounds.

Seven-year incidence of uncorrected refractive error among an elderly Chinese population in Shihpai, Taiwan: The Shihpai Eye Study

PURPOSE

To report the 7-year incidence of uncorrected refractive error in a metropolitan Chinese elderly population.

METHODS

The Shihpai Eye Study 2006 included 460/824 (55.8%) subjects (age range 72-94 years old) of 1361 participants in the 1999 baseline survey for a follow-up eye examination. Visual acuity was assessed using a Snellen chart, uncorrected refractive error was defined as presenting visual acuity (naked eye if without spectacles and with distance spectacles if worn) in the better eye of <6/12 that improved to no impairment (≥6/12) after refractive correction.

RESULTS

The 7-year incidence of uncorrected refractive error was 10.5% (95% confidence interval (CI): 7.6-13.4%). 92.7% of participants with uncorrection and 77.8% with undercorrection were able to improve at least two lines of visual acuity by refractive correction. In multivariate analysis controlling for covariates, uncorrected refractive error was significantly related to myopia (relative risk (RR): 3.15; 95% CI: 1.31-7.58) and living alone (RR: 2.94; 95% CI 1.14-7.53), whereas distance spectacles worn during examination was protective (RR: 0.35; 95% CI: 0.14-0.88).

CONCLUSION

Our study indicated that the incidence of uncorrected refractive error was high (10.5%) in this elderly Chinese population. Living alone and myopia are predisposing factors, whereas wearing distance spectacles at examination is protective.

Refractive errors in a Brazilian population: age and sex distribution

PURPOSE

To determine the prevalence of refractive errors and their distribution according to age and sex in a Brazilian population.

METHODS

This population-based cross-sectional study involved 7654 Brazilian inhabitants of nine municipalities of Sao Paulo State, Brazil, between March 2004 and July 2005. Participants aged >1 year were selected using a random, stratified, household cluster sampling technique, excluding individuals with previous refractive or cataract surgery. Myopia was defined as spherical equivalent (SE) ≤-0.5D, high myopia as SE ≤-3.0D, hyperopia as SE ≥+0.5D, high hyperopia as SE ≥+3D, astigmatism as ≤-0.5DC and anisometropia as ≥1.0D difference between eyes. Age, sex, complaints and a comprehensive eye examination including cycloplegic refraction test were collected and analysed using descriptive analysis, univariate and multivariate methods.

RESULTS

The prevalence of astigmatism was 59.7%, hyperopia 33.8% and myopia was 25.3%. Astigmatism had a progressive increase with age. With-the-rule (WTR) axes of astigmatism were more frequently observed in the young participants and the against-the-rule (ATR) axes were more frequent in the older subjects. The onset of myopia occurred more frequently between the 2nd and 3rd decades of life. Anisometropia showed a prevalence of 13.2% (95% CI 12.4-13.9; p < 0.001). There was an association between age and all types of refractive error and hyperopia was also associated with sex. Hyperopia was associated with WTR axes (odds ratio 0.73; 95% CI: 0.6-0.8; p < 0.001) and myopia with ATR axes (odds ratio 0.66; 95% CI: 0.6-0.8; p < 0.001).

CONCLUSIONS

Astigmatism was the most prevalent refractive error in a Brazilian population. There was a strong relationship between age and all refractive errors and between hyperopia and sex. WTR astigmatism was more frequently associated with hyperopia and ATR astigmatism with myopia. The vast majority of participants had low-grade refractive error, which favours planning aimed at correction of refractive error in the population.

The prevalence of refractive conditions in Puerto Rican adults attending an eye clinic system

PURPOSE

To determine the prevalence of refractive conditions in the adult population that visited primary care optometry clinics in Puerto Rico.

METHODS

A retrospective cross-sectional study of patients examined at the Inter American University of Puerto Rico School of Optometry Eye Institute Clinics between 2004 and 2010. Subjects considered had best corrected visual acuity by standardized subjective refraction of 20/40 or better. The refractive errors were classified by the spherical equivalent (SE): sphere+½ cylinder. Myopia was classified as a SE>-0.50D, hyperopia as a SE>+0.50 D, and emmetropia as a SE between -0.50 and +0.50, both included. Astigmatism equal or higher than 0.25 D in minus cylinder form was used. Patients with documented history of cataract extraction (pseudophakia or aphakia), amblyopia, refractive surgery or other corneal/ocular surgery were excluded from the study.

RESULTS

A total of 784 randomly selected subjects older than 40 years of age were selected. The estimated prevalence (95%, confidence interval) among all subjects was hyperopia 51.5% (48.0-55.0), emmetropia 33.8% (30.5-37.2), myopia 14.7% (12.1-17.2) and astigmatism 69.6% (68.8-73.3). Hyperopia was more common in females than males although the difference was not statistically significant. The mean spherical equivalent values was hyperopic until 70 y/o and decreased slightly as the population ages.

CONCLUSION

Hyperopia is the most common refractive error and its prevalence and seems to increase among the aging population who visited the clinics. Further programs and studies must be developed to address the refractive errors needs of the adult Puerto Rican population.

Prevalence of correctable visual impairment in primary school children in Qassim Province, Saudi Arabia

PURPOSE

The worldwide prevalence of refractive errors (RE), which is a common cause of treatable visual impairment among children, varies widely. We assessed the prevalence of correctable visual impairment (uncorrected RE) in primary school children in Qassim, Saudi Arabia.

METHODS

A cross-sectional study was conducted in 21 primary schools. A total of 5176 children (mean age 9.5±1.8 years), 2573 boys (49.7%) and 2603 girls (50.3%), underwent a comprehensive eye examination. The examinations consisted of visual acuity, autorefraction, cover test, ocular motility, pupillary evaluation, anterior segment examination, cycloplegic auto-refraction and dilated fundus examination with direct ophthalmoscopy. The children were divided into groups based on their age and gender.

RESULTS

The overall prevalence of RE in the better eye was 18.6% (n=963), and the prevalence of uncorrected RE 16.3% (n=846), with only 2.3% (n=127) of children wearing spectacles during examination. The prevalence of uncorrected myopia (5.8%) and myopic astigmatism (5.4%) was higher compared to that of hyperopic astigmatism (2.7%), mixed astigmatism (1.7%) and hyperopia (0.7%). The anisometropia prevalence was 3.6%. Risks for astigmatism, myopia and anisometropia were positively associated with age. In addition, myopia and anisometropia risks were also associated with female gender, while risk of astigmatism was correlated with male gender. Few children with vision reducing RE wore spectacles; an additional 16.3% of children could benefit from spectacle prescription.

CONCLUSION

The prevalence of uncorrected RE in children is relatively high and represents an important public health problem in school-aged children in Qassim province. Performance of routine periodical vision screening throughout childhood may reverse this situation.

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.

Population-based assessment of sensitivity and specificity of a pinhole for detection of significant refractive errors in the community

BACKGROUND

Measurements of refractive errors through subjective or automated refraction are not always possible in rapid assessment studies and community vision screening programs; however, measurements of vision with habitual correction and with a pinhole can easily be made. Although improvements in vision with a pinhole are assumed to mean that a refractive error is present, no studies have investigated the magnitude of improvement in vision with pinhole that is predictive of refractive error. The aim was to measure the sensitivity and specificity of 'vision improvement with pinhole' in predicting the presence of refractive error in a community setting.

METHODS

Vision and vision with pinhole were measured using a logMAR chart for 488 of 582 individuals aged 15 to 50 years. Refractive errors were measured using non-cycloplegic autorefraction and subjective refraction. The presence of refractive error was defined using spherical equivalent refraction (SER) at two levels: SER greater than ± 0.50 D sphere (DS) and SER greater than ±1.00 DS. Three definitions for significant improvement in vision with a pinhole were used: 1. Presenting vision less than 6/12 and improving to 6/12 or better, 2. Improvement in vision of more than one logMAR line and 3. Improvement in vision of more than two logMAR lines.

RESULTS

For refractive error defined as spherical equivalent refraction greater than ± 0.50 DS, the sensitivities and specificities for the pinhole test predicting the presence of refractive error were 83.9 per cent (95% CI: 74.5 to 90.9) and 98.8 per cent (95% CI: 97.1 to 99.6), respectively for definition 1. Definition 2 had a sensitivity 89.7 per cent (95% CI: 81.3 to 95.2) and specificity 88.0 per cent (95% CI: 4.4 to 91.0). Definition 3 had a sensitivity of 75.9 per cent (95% CI: 65.5 to 84.4) and specificity of 97.8 per cent (95% CI: 95.8 to 99.0). Similar results were found with spherical equivalent refraction greater than ±1.00 DS, when tested against the three pinhole-based definitions.

CONCLUSION

Refractive error definitions based on improvement in vision with the pinhole shows good sensitivity and specificity at predicting the presence of significant refractive errors. These definitions can be used in rapid assessment surveys and community-based vision screenings.

Age-related eye diseases and visual impairment among U.S. adults

BACKGROUND

Visual impairment is a common health-related disability in the U.S. The association between clinical measurements of age-related eye diseases and visual impairment in data from a national survey has not been reported.

PURPOSE

To examine common eye conditions and other correlates associated with visual impairment in the U.S.

METHODS

Data from the 2005-2008 National Health and Nutrition Examination Survey of 5222 Americans aged ≥40 years were analyzed in 2012 for visual impairment (presenting distance visual acuity worse than 20/40 in the better-seeing eye), and visual impairment not due to refractive error (distance visual acuity worse than 20/40 after refraction). Diabetic retinopathy (DR) and age-related macular degeneration (AMD) were assessed from retinal fundus images; glaucoma was assessed from two successive frequency-doubling tests and a cup-to-disc ratio measurement.

RESULTS

Prevalence of visual impairment and of visual impairment not due to refractive error was 7.5% (95% CI=6.9%, 8.1%) and 2.0% (1.7%, 2.3%), respectively. The prevalence of visual impairment not due to refractive error was significantly higher among people with AMD (2.2%) compared to those without AMD (0.8%), or with DR (3.5%) compared to those without DR (1.2%). Independent predictive factors of visual impairment not due to refractive error were AMD (OR=4.52, 95% CI=2.50, 8.17); increasing age (OR=1.09 per year, 95% CI=1.06, 1.13); and less than a high school education (OR=2.99, 95% CI=1.18, 7.55).

CONCLUSIONS

Visual impairment is a public health problem in the U.S. Visual impairment in two thirds of adults could be eliminated with refractive correction. Screening of the older population may identify adults at increased risk of visual impairment due to eye diseases.

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.

Incidence of visual impairment over a 20-year period: the Beaver Dam Eye Study

PURPOSE

To describe visual impairment (VI) over a 20-year period and its associations with age-related eye diseases and socioeconomic factors in the Beaver Dam Eye Study.

DESIGN

Population-based cohort study.

PARTICIPANTS

Four thousand nine hundred twenty-six persons 43 to 86 years of age participated in the baseline examination phase from 1988 through 1990, and 3721, 2962, 2375, and 1913 persons participated in follow-up examinations each spaced 5 years apart from 1993 through 1995, 1998 through 2000, 2003 through 2005, and 2008 through 2010, respectively.

METHODS

Best-corrected visual acuity after refraction, assessed by the Early Treatment Diabetic Retinopathy Study protocol.

MAIN OUTCOME MEASURES

Incidence of VI, defined as best-corrected visual acuity of poorer than 20/40 in the better eye in persons with one or both eyes 20/40 or better at the beginning of a 5-year interval, and incidence of severe VI, defined as best-corrected visual acuity of 20/200 or worse in the better eye in persons with one or both eyes better than 20/200 at the beginning of a 5-year interval.

RESULTS

Overall incidence of VI between examinations (5-year interval) was 1.4% (varying from 0.1% in persons 50-54 years of age to 14.6% in those 85 years of age and older), whereas for severe VI it was 0.4% (varying from 0.0% in persons 50-54 years of age to 6.9% in those ≥ 85 years of age). The incidence of VI decreased for each (2003-2005 to 2008-2010; odds ratio fourth interval vs. first interval, 0.53; 95% confidence interval, 0.32-0.87; P = 0.01 period after adjustment for age, from the first 5-year interval between examinations (1988-1990 to 1993-1995) to the fourth and most recent 5-year interval ). This period effect was no longer significant after adjustment for age-related macular degeneration. Age-related macular degeneration remained the leading cause of incident severe VI (54% of eyes with incident severe VI, which was as low as 40% and as high as 57% for specific visits), with no evidence of a trend across visits. The overall frequency of VI correctable with new refraction was 38% of all eyes with VI.

CONCLUSIONS

These data provide population-based estimates that show a high (15%) 5-year incidence of VI in persons 85 years of age and older. Age-related macular degeneration remained the leading cause of severe VI in this population over the 20 years of the study.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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.

Causes of blindness and visual impairment in Latin America

We review what is known in each country of the Latin American region with regards to blindness and visual impairment and make some comparisons to Hispanic populations in the United States. Prevalence of blindness varied from 1.1% in Argentina to 4.1% in Guatemala in people 50 years of age and older, with the major cause being cataract. Diabetic retinopathy and glaucoma are starting to make serious inroads, although epidemiological data are limited, and age-related macular degeneration is now a concern in some populations. Infectious diseases such as trachoma and onchocerciasis are quickly diminishing. Although progress has been made, retinopathy of prematurity remains the major cause of childhood blindness. If VISION 2020 is to succeed, many more epidemiological studies will be needed to set priorities, although some can be of the Rapid Assessment of Avoidable Blindness design. Developing the infrastructure for screening and treatment of ophthalmic disease in Latin America continues to be a challenge.

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.