[Prevalence of near vision deficiency and related factors: a population-based study]

BCLA CLEAR Presbyopia: Epidemiology and impact

The global all-ages prevalence of epidemiologically-measured 'functional' presbyopia was estimated at 24.9% in 2015, affecting 1.8 billion people. This prevalence was projected to stabilise at 24.1% in 2030 due to increasing myopia, but to affect more people (2.1 billion) due to population dynamics. Factors affecting the prevalence of presbyopia include age, geographic location, urban versus rural location, sex, and, to a lesser extent, socioeconomic status, literacy and education, health literacy and inequality. Risk factors for early onset of presbyopia included environmental factors, nutrition, near demands, refractive error, accommodative dysfunction, medications, certain health conditions and sleep. Presbyopia was found to impact on quality-of-life, in particular quality of vision, labour force participation, work productivity and financial burden, mental health, social wellbeing and physical health. Current understanding makes it clear that presbyopia is a very common age-related condition that has significant impacts on both patient-reported outcome measures and economics. However, there are complexities in defining presbyopia for epidemiological and impact studies. Standardisation of definitions will assist future synthesis, pattern analysis and sense-making between studies.

Understanding Presbyopia in Asmara: Prevalence, Association with Refractive Error, and Age-Based Addition

Background

Presbyopia is an age-related progressive decrease of near vision, corrected by near addition glasses. These age-appropriate glasses, however, vary across different geographical locations and populations. But there is no existing information on the age-based addition for Asmara and high number of uncorrected presbyopes, so this study determined the required age-based addition for the presbyopes in Asmara.

Methods

A cross-sectional study was conducted on patients aged 35-60 years who visited all eye centers in the city. Patients with best-corrected visual acuity in both eyes better than 6/9 were included in the study. Near add was calculated using Monocular Estimation Method (MEM) and amplitude of accommodation results. Data entry and analysis were performed using Statistical Package for the Social Sciences v. 20.

Results

This study included 1310 participants of whom 48.5% were females and 51.5% were males. The prevalence of presbyopia was found to be 74.1% out of which 44% were females. There were 35.6% of the participants with a previous prescription for glasses, though only 24% of the participants presented with glasses on. Among the different occupational categories, laborers were the ones who had the highest number of presbyopes (79.5%), office workers (73%), and housewives (68.7%). The mean age of those with presbyopes was 49.5 ± 5.8 years. Multivariable analysis performed for presbyopia showed that older age and female sex were associated with a higher likelihood of presbyopia (<0.005). An addition table was prepared separately for males and females. On post-hoc tests, no significant association was found between the given and the different refractive status.

Conclusion

The study showed that there is a high level of uncorrected presbyopes in the city, so the availability of refraction sites and glasses accessibility needs to increase. The near addition demand for this population varies from the previously stated amount in other countries. Therefore, guidelines specifically prepared for a society are necessary.

Potential productivity loss from uncorrected and under-corrected presbyopia in low- and middle-income countries: A life table modeling study

Objective

To estimate the burden of potential productivity losses due to uncorrected and under-corrected presbyopia in LMICs among the working-age population in both the cross-sectional and longitudinal manner.

Methods

We extracted data for the prevalence of presbyopia from the Global Burden of Diseases (GBD), Injuries, and Risk Factors Study 2019. Data for the gross domestic product (GDP) per capita were extracted from the World Bank database and Central Intelligence Agency's World Factbook. We introduced life table models to construct age cohorts (in 5-year age groups) of the working-age population (aged from 40 to 64 years old) in LMICs, with simulated follow-up until 65 years old in people with and without uncorrected presbyopia. The differences in productivity-adjusted life years (PALYs) lived and productivity between these two cohorts were calculated. The potential productivity loss was estimated based on GDP per capita. The WHO standard 3% annual discount rate was applied to all years of life and PALYs lived.

Results

In 2019, there were 238.40 million (95% confidence interval [CI]: 150.92-346.78 million) uncorrected and under-corrected presbyopia cases in LMICs, resulting in 54.13 billion (current US dollars) (95% confidence interval [CI]: 34.34-79.02 billion) potential productivity losses. With simulated follow-up until retirement, those with uncorrected and under-corrected presbyopia were predicted to experience an additional loss of 155 million PALYs (an average loss of 0.7 PALYs per case), which was equivalent to a total loss of US$ 315 billion (an average loss of US$ 1453.72 per person).

Conclusions

Our findings highlight the considerable productivity losses due to uncorrected and under-corrected presbyopia in LMICs, especially in a longitudinal manner. There is a great need for the development of enabling eye care policies and programs to create access to eye care services, and more healthcare investment in the correction of presbyopia in the working-age population in LMICs. This study could provide evidences for some potential health-related strategies for socio-economic development.

Prevalence, risk factors and association with glycemic levels of presbyopia in South Indian population

Purpose

To determine the prevalence of presbyopia and its association with elevated glycemic levels in subjects ≥40 years of age in the South Indian population of Chennai.

Methods

This was a retrospective study. Subjects were included from the Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular genetics Study (SN-DREAMS 1). Demographic data, detailed medical and ocular history, comprehensive eye examination, and biochemical investigations were performed. Glycosylated hemoglobin results were categorized as controls (4%-5.6%), prediabetic (5.7%-6.4%), and diabetic (≥6.5%) groups. The given presbyopic correction was divided into two groups as within and outside donders limit. Prevalence rates and mean values were determined and compared among the three glycemic groups. The Student t test, the Chi-square test, and multivariate logistic regression analyses were performed.

Results

The overall prevalence of presbyopia from our previously conducted SN-DREAMS 1 population of 1414 patients was 79.77% (95% CI: 0.775-0.818). In total, 1128 participants were included for our current secondary analysis with a mean age of 54.40 years (range: 40-83). The number of subjects within and outside donders limit was 1044 (92.55%) and 84 (7.44%), respectively. In each age group (40-49, 50-59, ≥60) regardless of being within or outside donders limits, an increasing trend in the prevalence of presbyopia was noted based on increasing glycemic levels.

Conclusion

Our study demonstrated a high prevalence of presbyopia in the South Indian population of Chennai. Findings show that the prevalence of presbyopia in different age groups increases with worsening diabetes status.

[Validation study on self-reported visual impairment among undergraduate students at the Federal University of Pelotas]

The objectives of the study were to assess the prevalence of self-reported visual impairment among undergraduate students between 18 and 39 years of age at the Federal University of Pelotas, and to validate a question about visual impairment in a subsample of the participants. A cross-sectional study was conducted by asking the question "Do you have any difficulty seeing up close and/or in the distance?" As the gold standard for the validation study, visual acuity (VA) was measured using the Snellen chart. Patients with VA less than 20/40 in either eye were considered to have reduced VA. The prevalence of self-reported visual impairment was 37.3% (95% CI: 35.1-39.6) and VA less than 20/40 in either eye was 6.9% (95% CI: 5.3-8.9). The question revealed sensitivity of 71.4% (95 CI: 57.8-82.7), specificity of 66.9% (95% CI: 63.4-70.2), positive predictive value of 13.8% (95% CI: 10.0-18.3), and negative predictive value of 96.9% (95% CI: 95,1-98.2). The results indicated a high prevalence of self-reported visual impairment among university students. The question showed reasonable sensitivity and specificity and high negative predictive value and may be used for screening for ophthalmological evaluation among young adult university students.

Unmet need for presbyopia correction and its associated factors among school teachers in Hawassa city, South Ethiopia

BACKGROUND

Presbyopia is a decline in the amplitude of accommodation with the onset in the age range 40-45 years affecting near visual task performance. As the age of presbyopia onset coincides with productive age, it results in great productivity loss especially in those with high near visual demand like teachers. A maximum near vision potential is essential for teachers in ensuring the quality of education, as most of the students' evaluations and scripts are assessed manually in Ethiopia. The prevalence of unmet need for presbyopia correction among school teachers ranges from 38.5-70.4% worldwide. Though presbyopia is a common ocular condition, there is limited evidence regarding the unmet need for presbyopia correction in Ethiopia as well as in Hawassa city. Therefore, this study aimed to determine the magnitude of unmet need for presbyopia correction and its associated factors among school teachers in Hawassa city, South Ethiopia.

METHODS

A school-based cross-sectional study was conducted among teachers older than 35 years. A simple random sampling technique was used to select participants using name lists as a sampling frame from 69 schools. The participants selected underwent for distance and near visual acuity test. Those with distance visual acuity of 6/12 or worse were refracted before near visual acuity test. Information on the spectacle use and associated factors was obtained using the interviewer-administered questionnaire. Data analysis was done using Statistical Package for Social Sciences software version 20. Binary logistic regression analysis was performed to assess association between independent variables and the unmet need for presbyopia correction.

RESULTS

A total of 459 study participants were included in the study with a response rate of 95.21%.The unmet need for presbyopia correction was 51.26% (95%CI: 46.7-55.6%). Female gender (AOR = 2.50; 95%CI: 1.51-4.15), age 36-45 (AOR = 4.12; 95%CI: 1.46-11.76), unaware of presbyopia (AOR = 2.36; 95%CI: 1.2-4.66) and self-rating of current vision as good (AOR = 3.5; 95%CI: 1.61-7.6) were factors significantly associated with the unmet need for presbyopia.

CONCLUSIONS

The burden of unmet need for presbyopia correction is a moderate priority according to the World Health Organization for presbyopia correction services criteria. A school-based presbyopia awareness creation program is important to reduce this huge burden.

Presbyopic correction use and its impact on quality of vision symptoms

AIM

To assess real-world adoption of presbyopic correction and its impact on quality of vision.

METHOD

The use of visual corrections by 529 sequential patients (aged 36 years to 85 years, 50.4% female) attending 4 optometric practices in diverse areas across London were surveyed by interview and completed the quality of vision (QoV) questionnaire to evaluate visual symptoms.

RESULTS

Over half of the population (54.7%) managed without glasses at least some of the time, while between 30 and 40% wore distance, reading and progressive spectacles with those using Progressive Addition Lenses wearing them over 80% of the time, while those wearing reading spectacles only approximately 25% of the time. Age, sex and driving frequency had no effect of QoV (p>0.05), whereas the distance of the task significantly impacted QoV (p<0.01). In all QoV metrics, regardless of the far, intermediate or near blur assessment, QoV was rated higher by patients whose main tasks were far focused (n=231, 43.9%), than those who principally conduct intermediate tasks (n=165, 31.4%) and worse still for those whose main tasks were near (n=130, 24.7%), regardless of the form of correction.

CONCLUSION

Majority of tasks are in the distance and these had a higher QoV than intermediate tasks with near focused tasks being even worse. It is important to discuss with patients the principal distance of the tasks they generally perform and the forms of presbyopic correction used from the outset.

Presbyopia and Ocular Conditions Causing Near Vision Impairment in Older Adults From the Brazilian Amazon Region

PURPOSE

To investigate the prevalence and causes of near vision impairment (NVI) in a population of older adults from the Brazilian Amazon Region.

DESIGN

Population-based cross-sectional study.

METHODS

Cluster sampling was used in randomly selecting subjects 45 years of age and older from urban and rural areas of Parintins city, Brazil. Participants underwent ophthalmic examination, including uncorrected (UCNVA), presenting (PNVA), and best-corrected near visual acuity (BCNVA) from each eye; biomicroscopy; funduscopy; and subjective refraction, including testing with additional lenses for near vision optical correction. A principal cause for NVI was assigned by the ophthalmologist and presbyopia was defined as UCNVA ≤ 20/40 changing to > 20/40 with BCNVA. Free-of-charge glasses were provided for those in need.

RESULTS

A total of 2384 subjects were enumerated and 2025 had reliable NVA measurements from both eyes. The prevalence of NVI in the better-seeing eye was 96.5% with UCNVA, decreasing to 81.1% with PNVA and to 20.5% with BCNVA. Presbyopia was the principal cause of NVI in 71.8%, followed by cataract (16.5%) and pterygium (2.5%), and was associated with younger age and high schooling. Glasses for near vision were prescribed and provided to 1414 (69.8%) participants.

CONCLUSIONS

A high prevalence of NVI was detected even in those wearing glasses for near. Prescription and provision of low-cost reading glasses should be considered by Brazilian health authorities to address this easily and promptly correctable form of vision impairment.

Impact of Presbyopia and Its Correction in Low- and Middle-Income Countries

Presbyopia affects more than 1 billion people worldwide, and the number is growing rapidly due to the aging global population. Uncorrected presbyopia is the world's leading cause of vision impairment, and as with other causes. The burden falls unfairly on low- and middle-income countries (LMICs), in which rates of presbyopic correction are as low as 10%. The importance of presbyopia as a cause of vision impairment is further underscored by the fact that it strikes at the heart of the productive working years, although it can be safely and effectively treated with a pair of inexpensive glasses. To galvanize action for programs to address uncorrected presbyopia in the workplace and beyond LMICs, it is crucial to build a solid evidence base detailing the impact of presbyopia and its correction in important areas such as work productivity, activities of daily living, visual function, and quality of life. The aim of this review was to provide an up-to-date reference for program planners and policymakers seeking to build support for programs of presbyopia correction, particularly in low-resource settings.

Global Prevalence of Presbyopia and Vision Impairment from Uncorrected Presbyopia: Systematic Review, Meta-analysis, and Modelling

TOPIC

Presbyopia prevalence and spectacle-correction coverage were estimated by systematic review and meta-analysis of epidemiologic evidence, then modeled to expand to country, region, and global estimates.

CLINICAL RELEVANCE

Understanding presbyopia epidemiologic factors and correction coverage is critical to overcoming the burden of vision impairment (VI) from uncorrected presbyopia.

METHODS

We performed systematic reviews of presbyopia prevalence and spectacle-correction coverage. Accepted presbyopia prevalence data were gathered into 5-year age groups from 0 to 90 years or older and meta-analyzed within World Health Organization global burden of disease regions. We developed a model based on amplitude of accommodation adjusted for myopia rates to match the regionally meta-analyzed presbyopia prevalence. Presbyopia spectacle-correction coverage was analyzed against country-level variables from the year of data collection; variation in correction coverage was described best by a model based on the Human Development Index, Gini coefficient, and health expenditure, with adjustments for age and urbanization. We used the models to estimate presbyopia prevalence and spectacle-correction coverage in each age group in urban and rural areas of every country in the world, and combined with population data to estimate the number of people with near VI.

RESULTS

We estimate there were 1.8 billion people (prevalence, 25%; 95% confidence interval [CI], 1.7-2.0 billion [23%-27%]) globally with presbyopia in 2015, 826 million (95% CI, 686-960 million) of whom had near VI because they had no, or inadequate, vision correction. Global unmet need for presbyopia correction in 2015 is estimated to be 45% (95% CI, 41%-49%). People with presbyopia are more likely to have adequate optical correction if they live in an urban area of a more developed country with higher health expenditure and lower inequality.

CONCLUSIONS

There is a significant burden of VI from uncorrected presbyopia, with the greatest burden in rural areas of low-resource countries.

Corneal Refractive Procedures for the Treatment of Presbyopia

Purpose:

Refractive surgery has been in use for a long time and is evolving at a fast pace with several new corneal procedures being used for the correction of presbyopia. The purpose of this article is to give a comprehensive review of the literature to evaluate the outcome and success of different corneal refractive surgical procedures in presbyopic patients.

Methods:

We performed a comprehensive search on PubMed to identify published reports of the various procedures utilized in the past and present to correct presbyopia. The outcomes of these procedures were recorded.

Results and conclusion:

We found that varying rates of success have been reported with these procedures. The results of our exhaustive search are presented in this report for review.

Progression of Near Vision Loss and Incidence of Near Vision Impairment in an Adult Chinese Population

PURPOSE

To investigate the progression of near vision loss and the cumulative incidence of near vision impairment (NVI) 6 years after initial examination of an urban Chinese cohort.

DESIGN

Population-based, prospective cohort study.

PARTICIPANTS

People aged ≥35 years examined at baseline in the Yuexiu District of Guangzhou, China.

METHODS

Participants examined at baseline were invited for 2-year and 6-year follow-up examinations in 2010 and 2014, respectively. Examinations included noncycloplegic autorefraction and binocular near visual acuity (NVA) with and without current near correction measured at 40 cm using a LogMAR ETDRS near vision tumbling E chart. Those with uncorrected binocular NVA (UCNVA) ≤20/40 underwent subjective refraction to obtain best-corrected binocular NVA (BCNVA).

MAIN OUTCOME MEASURES

Change in UCNVA between baseline and 2014 follow-up examinations and the 6-year cumulative incidence of vision impairment based on 3 definitions: NVA ≤20/40, ≤20/50, and ≤20/63.

RESULTS

Among the 1817 baseline participants, 1595 (87.8%) were reexamined in 2010 and 1427 (78.5%) in 2014. Mean vision loss between baseline and the 2014 follow-up was 1.54 (±1.74) lines of UCNVA. Vision loss was associated with age 80 years or older, less education, and better baseline UCNVA. The 6-year cumulative incidence of uncorrected binocular NVI (UCNVI) across the 3 vision impairment definitions was 55.2% (95% confidence interval [CI], 46.1%-64.3%), 51.3% (95% CI, 44.0%-58.7%), and 42.4% (95% CI, 35.5%-49.3%), respectively. With best-corrected binocular NVI (BCNVI), incidence was 6.89% (95% CI, 4.28%-9.50%), 5.17% (95% CI, 2.89%-7.44%), and 2.62% (95% CI, 1.11%-4.12%), respectively. A higher incidence of UCNVI was associated with worse baseline UCNVA for all 3 impairment definitions. Similarly, incidence of BCNVI was associated with worse baseline BCNVA, but also with older age and education at the primary level or less. Gender was not significant for either UCNVI or BCNVI.

CONCLUSIONS

Approximately half of those aged 35 years or older develop UCNVI in 6 years, the overwhelming majority of whom can be corrected with spectacles. Cost-effective strategies to provide spectacles to this at-risk population remains an issue requiring further study.

Ageing doctors

Doctors are neither more nor less susceptible than the general population to the effects of ageing. The relevance of deterioration with age depends on the nature of the work undertaken. Reduced muscle strength and visual and auditory deterioration can compromise clinical ability. Accumulation of chronic disease further reduces capacity. Cognitive decline is of particular importance, as good medical care requires considerable cognitive function. Patient safety is paramount, yet older doctors are an important part of the medical workforce and their value should be recognised. Changes in patient case mix, work place support systems and individual adjustments can assist safe practice. Deterioration in health should be acknowledged and requires proactive management. Current methods of ensuring competence are inadequate for supporting ageing doctors. A new initiative is recommended comprising collaboration between regulators, colleges and employing institutions to support the ageing doctor in providing safe and effective practice.

A novel strategy for management of uncorrected refractive errors in urban slums

BACKGROUND

Blindness and Vision impairment remains a major public health issue not only in rural but also in urban areas. Concept of using peripheral health centers to render primary health care services to the community was a WHO proposed model. However, establishing them in urban slums is a challenge as most of the slums are illegal establishments. So, aim was to establish vision centers for providing primary eye care services in the urban slums of Mumbai, West India.

METHODS

Vision centers were established in various slum pockets of Mumbai from the year 2008 till 2009. Refraction and screening for ocular morbidity were carried out for those who attended this center and management for uncorrected refractive errors was done.

RESULTS

Data from 6 such vision centers located in various slum pockets of Mumbai city from April 9 to March 2011 were collected and analyzed. Of the 19,550 adults, 2270 (11.61%) had moderate vision impairment with presenting visual acuity of <0.5 LogMAR in both eyes. Severe Visual impairment was seen in (723) 3.70%. Blindness was seen in (357) 1.82%. Of the 2993, which were moderately and severely visually impaired, 1893 subjects that is, 63.24% of them improved to 0.2 LogMAR or better with spectacle correction.

CONCLUSIONS

About 63.24% of visual impairment was due to uncorrected refractive errors, these included both moderately and severely vision impaired. Totally, 357 (1.82%) were also identified as blind. This model of vision centers has a role in the identification and management of sight-threatening problems.

Review of the impact of presbyopia on quality of life in the developing and developed world

PURPOSE

To examine the public health impact of presbyopia regarding its effect on quality of life (QoL) and society in both the developed and developing worlds.

METHODS

A database was created from articles found on PubMed, the Cochrane Library and Science Direct using the following search terms: presbyopia, QoL, accommodation, impact, cost, prevention, treatment and public health. Articles were accepted into the database if they addressed presbyopia and public health.

RESULTS

This study showed in the developed world presbyopic subjects treated with reading glasses suffered a reduction in QoL parameters compared with those who were younger and emmetropic. A small minority of subjects were assessed to be a candidate for additional non-spectacle treatment measures. In undeveloped areas, the manifestations of presbyopia were similar to the developed world in symptoms, age and reduced QoL. However, there was inadequate treatment of this condition, even with reading glasses. The availability of reading glasses ranged from 6 to 45%. Activities of daily living could not be accomplished as easily without near correction of reading. Reasons described for the lack of correction included: lack of access to medical care, poor awareness of decreased near vision, lack of motivation and cost. Overall scant data exist regarding presbyopia and its impact and how treatment affects QoL.

CONCLUSIONS

This review suggests that the effect of presbyopia and its treatments on QoL remain poorly described and incompletely treated, especially in developing areas of the world.

A survey of ocular diseases in an isolated rural Haitian community: a retrospective evaluation

PURPOSE

To report the prevalence and incidence of ophthalmic pathology from a small, rural town in Haiti and to determine the leading causes of blindness in this population.

DESIGN

Retrospective study from 2002 to 2009. Data collected include visual acuity, intraocular pressure, and ocular and family history.

METHOD

The study was conducted in a single center--Hospital de Lascahobas, Lascahobas, Haiti. Patients were natives of Lascahobas and the surrounding areas. Treatments were dispensed as indicated or warranted.

RESULTS

A total of 3702 patients were seen and examined: 51.52% were male and 49.48% were female. Ages ranged from 6 months to 92 years (mean, 48.69 SD +/- 49.94). Uncorrected refractive error was the most common diagnosis (53.27%), followed by presbyopia (43.76%), hyperopia (34.03%), and myopia (22.21%). A total 981 patients (26.50%) were diagnosed with cataract. Three hundred twenty-three (32.93%) cataract surgeries were performed. The overall postoperative complications rate was 9.29%. A total of 706 patients (19.07%) were diagnosed with glaucoma: 23.65% were glaucoma suspect and 76.35% were diagnosed with open-angle glaucoma (POAG). Of those diagnosed with POAG, 35.06% had end-stage (absolute) glaucoma. The mean age at diagnosis was 52.56 SD +/- 8.2 years. The mean intraocular pressure was 24.07 and 25.60 mm Hg, and the mean cup to disc ratio of the right eye (OD) and the left eye (OS), respectively, was 0.67 and 0.72.

CONCLUSIONS

Glaucoma was the most common cause for blindness. The most common cause of correctable vision loss was uncorrected refractive error followed by cataract. Providing constant eye care in this region will most likely decrease the incidence of correctable and permanent vision loss.

Presbyopia, spectacles use and spectacle correction coverage for near vision among cloth weaving communities in Prakasam district in South India

PURPOSE

To assess the prevalence of presbyopia, spectacles use and spectacle correction coverage for near vision among weaving communities in Prakasam district in the South Indian state of Andhra Pradesh.

METHODS

A population based cross sectional study was conducted among a population aged ≥40 years. Distance visual acuity was assessed at 6 m. Near vision was assessed using N notation charts at a fixed distance of 40 cm. Presbyopia was defined as binocular unaided near vision <N8 and improving to ≥N8 with near addition lenses. Functional presbyopia was defined as presenting near vision <N8 and improving to ≥N8 with near addition lenses. A questionnaire was used to collect information on spectacles use. In order to calculate spectacle correction coverage for presbyopia, met presbyopia need was defined as the percentage of people who presented with presbyopia correction and achieved binocular N8 using it. Unmet presbyopia need was defined as the percentage of people who had either under corrected or uncorrected binocular near vision worse than N8 that would improve with correction to at least N8.

RESULTS

Of 2848/3000 enumerated subjects (94.0%) participated. Four hundred individuals with distance visual impairment were excluded from the analysis. Among the remaining 2448 individuals, 46% were male and 49.1% had no formal education. The mean age among males was higher compared to females (p < 0.01). Based on unaided near vision, the prevalence of presbyopia was 61.8% (95% CI: 59.9-63.7) and the prevalence of functional presbyopia was 35.1% (95% CI: 33.2-37.0). Using multivariable analysis, it was found that functional presbyopia was significantly associated with female gender, no education and lack of spectacle use. Spectacle correction coverage was 43.2%. Among the 781 individuals who had no correction at the time of examination, 122 (15.6%) subjects reported having used spectacles previously. The reasons for discontinuation of spectacles were discomfort with spectacles (n = 57; 46.7%), damaged or lost spectacles (n = 45; 36.9%), ability to see clearly even without spectacles (n = 12; 9.8%) and other reasons (n = 8; 6.6%).

CONCLUSION

Although the prevalence of presbyopia (61.8%) was comparable with other studies, the prevalence of functional presbyopia (35.1%) was lower and linked with higher spectacle correction coverage (43.2%) in this weaving community. However, it still highlights a large unmet need and spectacle correction coverage that could be improved by the provision of good quality, affordable spectacles, which may also improve spectacles use.

Economic inequality in presenting near vision acuity in a middle-aged population: a Blinder-Oaxaca decomposition

PURPOSE

To investigate economic inequality and its determinants in near vision, in a middle-aged population.

METHODS

In this population-based study, the presenting near vision in the better eye was investigated as the main outcome. If this vision revealed a value ≥1.6 M, the participant was considered to have presenting near vision impairment (PNVI). The effect of variables studied on PNVI was investigated using logistic regression. Economic inequality in PNVI was investigated using the Oaxaca-Blinder decomposition method.

RESULTS

PNVI in the better eye was observed in 18.2% (95% CI 16.8 to 19.6) of participants. The prevalence of PNVI in the high and low economic groups was 11.7% (95% CI 10.3 to 13.0) and 28.5% (95% CI 26.0 to 31.0), respectively. Age and education were observed as the main factors in the explained portion of this gap and were in favour of the high economic group. Gender and eye care utilisation were factors affecting the unexplained portion of this gap and were in favour of the low economic group.

CONCLUSIONS

Economic inequality plays a significant role in PNVI, while age and education are among the main factors affecting this gap. The effect caused by any change in these two factors was found to have a greater effect on women with low economic status.

Near-vision impairment and unresolved vision problems in Indigenous Australian adults

BACKGROUND

  To describe near-vision impairment, self-reported unresolved vision problems and barriers to having near-vision correction in Indigenous Australians.

DESIGN

  A nationwide population-based study designed to determine the causes and prevalence of vision loss and utilization of eye care services.

PARTICIPANTS

  Indigenous Australians aged ≥40 years.

METHODS

  Using a multistage random cluster sampling methodology, 30 geographical areas stratified by remoteness were selected to obtain a representation of Indigenous Australians. Visual acuity was conducted using a standard E chart. A questionnaire collected data on eye health, eye care service utilization and vision-related quality of life.

MAIN OUTCOME MEASURES

  Near-vision impairment defined as presenting binocular near visual acuity <N8. Self-reported unresolved vision problems defined as anything considered an eye/vision problem by the participant, including distance and/or near-vision impairments, not resolved after seeking care and quality-of-life scores.

RESULTS

  Being aged 50-59 years (reference group 40-49 years), speaking a language other than English at home and vision loss (distance vision impairment and blindness) increased the odds of near-vision impairment. Of those with near-vision impairment, 37% (175/468) reported not having near-vision correction. Being aged 60-69 years, speaking a language other than English at home and having vision loss decreased the odds of having near-vision correction. Longer time since last consultation was associated with unresolved vision problems and worse quality-of-life scores.

CONCLUSION

  There remains a large unmet need in regard to near-vision correction. Many Indigenous adults have unresolved vision problems that could be resolved with regular consultations with eye care services.

Uncorrected refractive errors

Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC), were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR) Development, Service Development and Social Entrepreneurship.

Meta-analysis of sex differences in presbyopia

PURPOSE

Uncorrected presbyopia is a significant cause of visual disability globally. Greater comprehension of the etiology of presbyopia and its contributing factors among medical and vision care providers could lead to changes in correction methods and account for sex differences in near-vision requirements.

METHODS

A meta-analysis was performed using nine cross-sectional studies that provided sufficient data to compare the prevalence and magnitude of presbyopia among men and women. This analysis was further subdivided into measurement methods to determine what differences in presbyopia might exist between men and women.

RESULTS

Studies of presbyopia including sex as a contributing factor were highly heterogenic (P = 0.01) but overall found female sex to be statistically significant in predicting earlier onset for presbyopia with an adjusted confidence interval (CI) using the Shore method of 95% CI [1.02, 1.45]. When limited to studies only measuring accommodative amplitude, female sex was not associated with presbyopia in a fixed effects model with a 95% CI [0.49, 1.07].

CONCLUSIONS

While an association between female sex and presbyopia for subjective measurements (near spectacle prescriptions and add powers) was indicated, measurements of accommodative amplitude show a weak tendency toward the opposite.

CONCLUSION

This suggests that increased association of presbyopia for women is not due to a physiologic difference in accommodation but rather due to other sex differences, such as tasks performed and viewing distances. Age-based correction nomograms for presbyopia should therefore consider these sex differences when prescribing add powers for near tasks.

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.

Presbyopia among public senior high school teachers in the Kumasi metropolis

BACKGROUND

Presbyopia if uncorrected causes inability to see and do near work. It is unavoidable as one ages. High school teachers whose work depends much on near work need proper and adequate correction of their presbyopia to increase effectiveness and efficiency.

OBJECTIVES

The aim was to determine the uptake of correction and prescription for presbyopia of presbyopic teachers of public Senior High School (S.H.S.).

DESIGN

Descriptive cross-sectional study.

METHODS

The study was conducted in 12 public S.H.S. in the Kumasi, with a total sample size of 298. Questionnaire was administered to teachers. Their visual acuity, refraction and ophthalmoscopy were done.

RESULTS

The prevalence of presbyopia among the teachers was 68.1%. Out of the number examined 197(66.1%) were males and 10(33.9%) were females. Amongst the presbyopes 60 did not have presbyopic correction, representing 29.6% of the presbyopes. A total of 52 presbyopic teachers required an add of +2.00DS and this was the highest diopter of correction needed (25.6%). Among those with presbyopic correction 55.5% of them use single vision type of correction whiles the remaining 44.5% use bifocals. Out of the 48% presbyopic teachers who have had their presbyopia corrected before, 6% were not wearing their correction.

CONCLUSION

The study has demonstrated a relatively higher prevalence of uncorrected presbyopia amongst teachers in public Senior High Schools in the Kumasi Metropolis of 29.6%. Among those with correction 6 % were not using their correction. Proper and adequate correction is needed by presbyopic teachers through screening to ensure their maximum performance.

Relação entre cognição (função executiva e percepção espacial) e equilíbrio de idosos de baixa escolaridade

O objetivo deste estudo foi investigar se défices na percepção visuoespacial e nas funções executivas apresentariam relação com o equilíbrio em idosos de baixa escolaridade. Participaram deste estudo 38 idosos (com média de idade 69,1±6,8 anos), com um a seis anos de escolaridade formal. Os testes aplicados foram: o teste de seqüência alfa-numérica - partes A, que avalia escaneamento visual e seqüenciamento (TSA-A), B, que avalia flexibilidade mental e memória operacional (TSA-B), considerando-se ainda o delta, que avalia função executiva (TSA-D); teste de cancelamento de estrelas (TCE), que avalia percepção espacial; a escala de equilíbrio de Berg (EEB) e a escala de eficácia de quedas (falls efficacy scale - international, FES-I), que avaliam equilíbrio e risco de quedas. As correlações foram verificadas pelo teste de Spearman, com p<0,05. Foram encontradas fortes correlações significativas entre as escalas de equilíbrio (EEB e FES-I) e o TSA-B (r=-0,61 e r=0,60, respectivamente); e correlações moderadas entre a EEB e o TSA-A (r=-0,51) e entre a FES-I e o TSA-D (r=0,55). Também houve correlações significativas entre as escalas de equilíbrio (EEB e FES-I) e o TCE (r=0,45 e r=-0,45, respectivamente). A função executiva e a percepção espacial apresentaram relação com o equilíbrio e com o medo de cair em idosos de baixa escolaridade. Quanto melhores forem a função executiva e a percepção espacial, melhor tenderá a ser o equilíbrio e menor tenderá a ser o medo de cair.

Carência de atenção à saúde ocular no setor público: um estudo de base populacional

Este estudo transversal de base populacional investigou a prevalência de utilização de serviços de saúde ocular e sua associação com fatores sócio-demográficos, necessidades em saúde e forma de financiamento da consulta. Avaliaram-se 2.960 indivíduos de 20 anos ou mais. Nos últimos cinco anos, 46% dos entrevistados e 30% daqueles com 50 anos ou mais não consultaram para os olhos. Dos que consultaram, 18% foram em óticas, e apenas 17% foram no setor público. O principal motivo foi não enxergar bem (69,5%). Falta de dinheiro (29%) e de tempo (24,6%) foram os principais motivos para ter deixado de consultar. Idade, escolaridade e nível econômico estiveram diretamente associados com ter consultado nos últimos cinco anos. Ser mulher, ter catarata, glaucoma e usar correção, bem como consultar no setor privado também estiveram positivamente associados com o desfecho. É preciso não só aumentar a participação do setor público, integrando a saúde ocular a todos os níveis de atenção, ampliando a participação de outros profissionais de saúde, como também intensificar o rastreamento de problemas oculares e a sua prevenção.

O Mestrado do Programa de Pós-graduação em Epidemiologia da UFPel baseado em consórcio de pesquisa: uma experiência inovadora

O Programa de Pós-graduação em Epidemiologia da UFPel realizou um intenso trabalho de auto-avaliação para resolver problemas identificados com seu curso de mestrado. O resultado foi a introdução de uma estrutura curricular baseada em dois pilares. De um lado, disciplinas de cunho teórico, fornecendo a base da formação do mestrando; de outro, disciplinas de cunho prático, onde os alunos trabalham coletivamente a construção de seu projeto de pesquisa, passando pela escolha de um tema, revisão da literatura, definição de objetivos e da metodologia. Esse esforço conjunto culmina na realização de um trabalho de campo único, na forma de um estudo transversal de base populacional, em que todos os mestrandos participam de maneira integral, obtendo dados para sua dissertação. Essa estratégia tem garantido a formação de mestres em epidemiologia com forte base teórica e com experiência de preparação e condução de um trabalho de campo. Além disso, tem sido possível manter um tempo de titulação abaixo de 24 meses. Cerca de 80% dos egressos têm publicado pelo menos um artigo baseado em seu mestrado. Destas publicações, quase 90% têm se dado em periódicos classificados como Internacional-A no Qualis da Capes.

A reassessment of sexual dimorphism in human senescence: theory, evidence, and causation

Age-specific mortality rates of men are higher than those of women, and men have shorter average life spans than women. This has been interpreted as evidence of sexual dimorphism in rates of senescence. However, because mortality can be caused by numerous factors in addition to senescence, higher mortality rates do not necessarily indicate more rapid senescence. In this paper, we (1) emphasize the necessity of decoupling mortality and senescence when considering sexual dimorphism in senescence, (2) present a theoretical framework for the hypothesis that selection affects senescence in human males and females differently due to different life history characteristics, (3) consider phenotypic evidence from the literature that human males show a later onset of senescence than human females, despite exhibiting higher mortality rates, and (4) discuss the potential roles of mutation accumulation and antagonistic pleiotropy in the evolution of sexual dimorphism in senescence.

Population-Based Study of Presbyopia in Rural Tanzania

OBJECTIVE

To determine the prevalence of presbyopia in a rural African population.

DESIGN

Cross-sectional prevalence study.

PARTICIPANTS

One thousand seven hundred nine persons age 40 years and older who resided in 3 villages and randomly selected neighborhoods of Kongwa town, Tanzania.

METHODS

Eligible persons were refracted and given best distance correction. Near vision was tested and corrected to the nearest 0.5 diopter. Presbyopia was defined as at least 1 line of improvement on a near visual acuity chart with an addition of a plus lens.

RESULTS

A total of 61.7% of eligible participants were presbyopic. A higher prevalence of presbyopia was associated with increased age, female gender, higher educational level, and residence in town (odds ratio = 3.09; 95% confidence interval: 2.46-3.90). The odds of developing presbyopia increased 16% per year of age from age 40 to 50, but the increase was nonsignificant at 1% per year after age 50. More severe presbyopia was associated with female gender and less with education.

CONCLUSIONS

This study provides the first population-based data on prevalence of presbyopia in a large, random sample of older Africans and suggests a high rate of presbyopia. Presbyopia plateaus after age 50, and it is more common in females. In addition, the 3-fold increased odds in town versus village dwellers was unexpected and suggests that research of other factors, including environmental factors, is warranted.

Impact of Presbyopia on Quality of Life in a Rural African Setting

PURPOSE

To determine the impact of uncorrected presbyopia on quality of life in rural Tanzania.

DESIGN

Cross-sectional study.

PARTICIPANTS

Population-based sample of 1709 village and town-dwelling adults aged 40 and older in the Kongwa district in rural Tanzania.

METHODS

Subjects underwent distance and near visual acuity testing to determine presbyopia. A near vision-related quality of life questionnaire was administered by trained interviewers to determine the degree of self-rated difficulty with tasks appropriate to life in a rural African setting, and how much near vision loss contributed to this difficulty.

MAIN OUTCOME MEASURES

Near vision-related quality of life.

RESULTS

Complete data were available for 1564 (92%) of the subjects. The prevalence rate of presbyopia was 62%. The majority of presbyopes (94%) did not have corrective near vision glasses. Compared with nonpresbyopes, being presbyopic increased the odds of reporting some difficulty with near vision tasks by 2-fold (odds ratio [OR], 2.04; 95% confidence interval [CI]: 1.57-2.66), odds of reporting moderate difficulty by 5-fold (OR 5.01; 95% CI: 3.19-7.89), and odds of reporting high difficulty by >8-fold (OR 8.52; 95% CI 3.13-23.10). The degree of presbyopia was associated with increasing difficulty with daily tasks (P<0.0001).

CONCLUSIONS

This is the first study to demonstrate that uncorrected presbyopia has a significant impact on vision-related quality of life in a rural African setting. The high prevalence of presbyopia, and increased aging of the population in developing countries, suggests that the World Health Organization's Vision 2020 refraction agenda should place greater emphasis on presbyopia.