Prevalence and causes of blindness and low vision in Timor-Leste

Development and Validation of a Lighting Facility for the Objective Assessment of the Visual Performance of Presbyopic Patients in a Series of Activities of Daily Living

Introduction The primary objective of this study is to develop and validate an experimental lighting facility that allows the evaluation of near and intermediate vision in different user-defined illuminance levels. Methods This is a prospective, randomized, controlled study. Normophakic patients populated three validation groups (VGs) according to their binocular uncorrected near visual acuity (UNVA): a) VG1, 0.0-0.1 logMAR; b) VG2, 0.4 logMAR; and c) VG3, 0.7 logMAR. All participants addressed 10 near and intermediate activities of daily life (ADLs) in the three following lighting settings: 1) 25 foot candles (fc)/3000 kelvins (K), 2) 50 fc/4000 K, and 3) 75 fc/6000 K. Results Thirty patients in each group performed all ADLs in the three lighting settings. VG1 demonstrated the best ADL scores in all ADLs and lighting settings, followed by the VG2. VG3 presented the worst scores. ADLs using printed material showed significant differences among the three lighting settings for all study groups, while ADLs using screens or needing manual dexterity demonstrated no significant differences except for the Screwdriver Test (ST) in VG1. All ADL scores demonstrated a high correlation with UNVA in all lighting settings (p < 0.001). Conclusion This is the first study that validates a lighting facility for comparative studies in patients with different near vision capacities performing a series of ADLs.

A search for trachoma in Timor-Leste: no evidence to justify undertaking population-based prevalence surveys

Purpose

We sought evidence to justify undertaking population-based trachoma surveys in Timor-Leste, believing that in the absence of such evidence, the country could be categorized as not needing interventions to eliminate trachoma.

Methods

We undertook a systematic review of published literature on trachoma in Timor-Leste, with results updated to 28 April 2018. We also undertook a series of clinic- and field-based screening exercises, consisting of: (1) in October 2015, conjunctival examination of all children attending a school in Vila, Atauro Island; (2) from 1 November 2016 to 30 April 2017, examination for trichiasis, by specifically-trained frontline eye workers, of all individuals presenting to the ophthalmic clinics of six referral hospitals and five district eye clinics; and (3) house-to-house case searches in a total of 110 households, drawn from three communities that were reported by investigators from the 2016 Rapid Assessment of Avoidable Blindness (RAAB) to include residents with trachoma.

Results

Three RAABs (2005, 2009–2010, 2016) and two relevant published papers were identified. The 2016 RAAB reported one female subject to have been diagnosed with trachomatous corneal opacity. Re-examination of that individual revealed that she had ankyloblepharon, without evidence of trichiasis or entropion. No children on Atauro Island, no clinic attendees, and no individuals examined in the targeted house-to-house searches had any sign of trachoma.

Conclusion

Trachoma is very unlikely to be a public health problem in Timor-Leste. It would not be appropriate to incur the costs of conducting formal population-based trachoma prevalence surveys here.

Building a national eye-care service in post-conflict Timor-Leste

Problem

Violent conflict left Timor-Leste with a dismantled health-care workforce and infrastructure after 2001. The absence of existing health and tertiary education sectors compounded the challenges of instituting a national eye-care system.

Approach

From 2001, the East Timor Eye Program coordinated donations and initially provided eye care through visiting teams. From 2005, the programme reoriented to undertake concerted workforce and infrastructure development. In 2008 full-time surgical services started in a purpose-built facility in the capital city. In 2014 we developed a clinical training pipeline for local medical graduates to become ophthalmic surgeons, comprising a local postgraduate diploma, with donor funding supporting master's degree studies abroad.

Local setting

In the population of 1.26 million, an estimated 35 300 Timorese are blind and an additional 123 500 have moderate to severe visual impairment, overwhelmingly due to cataract and uncorrected refractive error.

Relevant changes

By April 2018, six Timorese doctors had completed the domestic postgraduate diploma, three of whom had enrolled in master's degree programmes. Currently, one consultant ophthalmologist, seven ophthalmic registrars, two optometrists, three refractionists and four nursing staff form a tertiary resident ophthalmic workforce, supported by an international advisor ophthalmologist and secondary eye-care workers. A recorded 12 282 ophthalmic operations and 117 590 consultations have been completed since 2001.

Lessons learnt

International organizations played a pivotal role in supporting the Timorese eye health system, in an initially vulnerable setting. We highlight how transition to domestic funding can be achieved through the creation of a domestic training pipeline and integration with national institutions.

Prevalence and associated factors of low vision and blindness among patients attending St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia

BACKGROUND

Low vision and blindness are major public health problems. A vast burden of worlds visually impaired live in low-income settings especially in sub Saharan Africa. In such settings the blindness is associated with considerable disability and excess mortality, resulting in huge economic and social consequence. The main purpose of this study was to determine the prevalence and associated factors of low vision and blindness among patients at St. Paul's hospital millenium medical college.

METHODS

Institution based cross sectional design study was carried out from January to April, 2017 with sample size of 904. Systematic random sampling was used to recruit the study subjects. Retrospective medical chart review was done; data was entered into and analyzed by SPSS 23. Descriptive statistics such as frequency cross tabulation and chi-square test was carried out to translate data into information. P-value less than 0.05 was considered as statistically significant.

RESULTS

A total of 881 subjects with a response rate of 97.4% selected. The mean age of the study subjects was 44.53(SD: ± 21.85) with a range of 1-100 years. The prevalence of low vision and blindness was 91 (10.3% (95% CI: 8.2, 12.3)), and 64 (7.3 95%CI: 5.7, 9.0)) respectively. Age (p-value < 0.001), cataract (p-value = 0.002), glaucoma (p-value = 0.002) and age related macular degeneration (p-value < 0.001) were significantly associated with low vision and blindness.

CONCLUSION

Low vision and blindness found in this study was high. Age, cataract, glaucoma and age related macular degeneration were significantly associated with low vision and blindness. This amount of magnitude will be reduced if prevention, early diagnosis and management will be targeted towards avoidable causes of visual impairment.

Global prevalence and causes of visual impairment with special reference to the general population of Saudi Arabia

Objective:

This review was undertaken to highlight the worldwide prevalence and causes of visual impairment (VI), on the basis of a wide range of recent and clearly defined data and in comparison with published articles from the Kingdom of Saudi Arabia.

Methods:

These data are mainly based on PubMed indexed journal articles. Some representative surveys from each of the six WHO regions across the globe were included in this review with special reference to Saudi Arabian studies.

Results:

Published literature show that the prevalence and causes of VI varies markedly in different parts of the world and from region to region within the same country. Cataract, uncorrected refractive errors and glaucoma were shown to be the leading causes of VI worldwide and in Saudi Arabia. Diabetic retinopathy was found to have more contribution in Saudi Arabia due the higher prevalence of diabetes mellitus in this country.

Conclusion:

Epidemiological surveys about the prevalence and causes of VI are crucial for the formulation of preventive and curative measures. Data about VI are still scarce with a need to make wider population based surveys, worldwide and in Saudi Arabia for in-depth evaluation of the problem and better strategies to reduce the burden of VI.

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.

Prevalence and Causes of Unilateral Vision Impairment and Unilateral Blindness in Australia: The National Eye Health Survey

Importance

This study determines the prevalence of unilateral vision impairment (VI) and unilateral blindness to assist in policy formulation for eye health care services.

Objective

To determine the prevalence and causes of unilateral VI and unilateral blindness in Australia.

Design, Setting, and Participants

This cross-sectional population-based survey was conducted from March 2015 to April 2016 at 30 randomly selected sites across all strata of geographic remoteness in Australia. A total of 1738 indigenous Australians 40 years or older and 3098 nonindigenous Australians 50 years or older were included.

Main Outcomes and Measures

The prevalence and causes of unilateral vision impairment and blindness, defined as presenting visual acuity worse than 6/12 and 6/60, respectively, in the worse eye, and 6/12 or better in the better eye.

Results

Of the 1738 indigenous Australians, mean (SD) age was 55.0 (10.0) years, and 1024 participants (58.9%) were female. Among the 3098 nonindigenous Australians, mean (SD) age was 66.6 (9.7) years, and 1661 participants (53.6%) were female. The weighted prevalence of unilateral VI in indigenous Australians was 12.5% (95% CI, 11.0%-14.2%) and the prevalence of unilateral blindness was 2.4% (95% CI, 1.7%-3.3%), respectively. In nonindigenous Australians, the prevalence of unilateral VI was 14.6% (95% CI, 13.1%-16.3%) and unilateral blindness was found in 1.4% (95% CI, 1.0%-1.8%). The age-adjusted and sex-adjusted prevalence of unilateral vision loss was higher in indigenous Australians than nonindigenous Australians (VI: 18.7% vs 14.5%; P = .02; blindness: 2.9% vs 1.3%; P = .02). Risk factors for unilateral vision loss included older age (odds ratio [OR], 1.60 for each decade of age for indigenous Australians; 95% CI, 1.39-1.86; OR, 1.65 per decade for nonindigenous Australians; 95% CI, 1.38-1.96), very remote residence (OR, 1.65; 95% CI, 1.01-2.74) and self-reported diabetes (OR, 1.52; 95% CI, 1.12-2.07) for indigenous Australians, and having not undergone an eye examination in the past 2 years for nonindigenous Australians (OR, 1.54; 95% CI, 1.04-2.27). Uncorrected refractive error and cataract were leading causes of unilateral VI in both populations (70%-75%). Corneal pathology (16.7%) and cataract (13.9%) were leading causes of unilateral blindness in indigenous Australians, while amblyopia (18.8%), trauma (16.7%), and age-related macular degeneration (10.4%) were major causes of unilateral blindness in nonindigenous Australians.

Conclusions and Relevance

Unilateral vision loss is prevalent in indigenous and nonindigenous Australians; however, most cases are avoidable. As those with unilateral vision loss caused by cataract and posterior segment diseases may be at great risk of progressing to bilateral blindness, national blindness prevention programs may benefit from prioritizing examination and treatment of those with unilateral vision loss.

Prevalence and causes of blindness, visual impairment, and cataract surgery in Timor-Leste

Purpose

To estimate the prevalence and causes of blindness and visual impairment, cataract surgical coverage (CSC), visual outcome of cataract surgery, and barriers to uptake cataract surgery in Timor-Leste.

Method

In a nationwide rapid assessment of avoidable blindness (RAAB), the latest population (1,066,409) and household data were used to create a sampling frame which consists of 2,227 population units (study clusters) from all 13 districts, with populations of 450-900 per unit. The sample size of 3,350 was calculated with the assumed prevalence of blindness at 4.5% among people aged ≥50 years with a 20% tolerable error, 95% CI, and a 90% response rate. The team was trained in the survey methodology, and inter-observer variation was measured. Door-to-door visits, led by an ophthalmologist, were made in preselected study clusters, and data were collected in line with the RAAB5 survey protocol. An Android smart phone installed with mRAAB software was used for data collection.

Result

The age-gender standardized prevalence of blindness, severe visual impairment, and visual impairment were 2.8%, (1.8-3.8), 1.7% (1.7-2.3), and 8.1% (6.6-9.6), respectively. Cataract was the leading cause of blindness (79.4%). Blindness was more prevalent in the older age group and in women. CSC was 41.5% in cataract blind eyes and 48.6% in cataract blind people. Good visual outcome in the cataract-operated eyes was 62% (presenting) and 75.2% (best corrected). Two important barriers to not using available cataract surgical services were accessibility (45.5%) and lack of attendants to accompany (24.8%).

Conclusion

The prevalence of blindness and visual impairment in Timor-Leste remains high. CSC is unacceptably low; gender inequity in blindness and CSC exists. Lack of access is the prominent barrier to cataract surgery.

The prevalence of uncorrected refractive error in urban, suburban, exurban and rural primary school children in Indonesian population

Uncorrected refractive error (URE) is a major health problem among school children. This study was aimed to determine the frequency and patterns of URE across 4 gradients of residential densities (urban, exurban, suburban and rural). This was a cross-sectional study of school children from 3 districts in Yogyakarta and 1 district near Yogyakarta, Indonesia. The information regarding age, sex, school and school grader were recorded. The Snellen's chart was used to measure the visual acuity and to perform the subjective refraction. The district was then divided into urban, suburban, exurban and rural area based on their location and population. In total, 410 school children were included in the analyses (urban=79, exurban=73, suburban=160 and rural=98 school children). Urban school children revealed the worst visual acuity (P<0.001) and it was significant when compared with exurban and rural. The proportion of URE among urban, suburban, exurban and rural area were 10.1%, 12.3%, 3.8%, and 1%, respectively, and it was significant when compared to the proportion of ametropia and corrected refractive error across residential densities (P=0.003). The risk of URE development in urban, suburban, exurban, and rural were 2.218 (95%CI: 0.914-5.385), 3.019 (95%CI: 1.266-7.197), 0.502 (95%CI: 0.195-1.293), and 0.130 (95%CI:0.017-0.972), respectively. Urban school children showed the worst visual acuity. The school children in urban and suburban residential area had 2 and 3 times higher risk of developing the URE.

Multiple deprivation, vision loss, and ophthalmic disease in adults: global perspectives

The association between socioeconomic position and morbidity and mortality has long been recognized. We evaluate the evidence for an association between multiple aspects of deprivation and ocular health in a global context. This is a systematic review of studies that evaluated deprivation in the adult population in the context of the major acquired causes of visual loss such as cataract, diabetic eye disease, glaucoma, age-related macular degeneration, and ocular trauma. The search strategy identified relevant studies reported between 1946 and August 2016, with randomized control trials, case-control, cohort, and cross-sectional study designs being selected for inclusion. The studies identified in this review from across the world demonstrate the extent to which the common themes such as low educational attainment and low income may be associated with increased incidence of various sight-threatening conditions and may adversely affect access to specialist assessment and delivery of treatment. Health inequality may always persist, but an increased recognition of the importance of the various impacts of deprivation may empower policy makers to target limited resources to the most vulnerable groups in order to deliver the greatest benefit.

Prospective Study of Eye Disease in Timor-Leste: The East Timor Eye Program

PURPOSE

This study aimed to present the methodology of the East Timor Eye Program and report the prevalence of eye disease seen at the National Eye Centre during a 3-month sample period between June and August 2012.

DESIGN

Two hundred ninety-three new patients aged 17 years or older were assessed at the National Eye Centre in Dili, Timor-Leste.

METHODS

All participants received a comprehensive dilated eye examination that included distance visual acuity measurements, indirect fundoscopy, and a complete slit lamp assessment including gonioscopy and intraocular pressure measurement. Each patient completed an interview-administered general questionnaire, and information on general health, ocular history, and medication was obtained. Anthropometric measurements were also taken and recorded.

RESULTS

A total of 293 patients, 183 males (62.5%) and 110 females (37.5%), aged between 17 and 88 years (mean, 47.66 years) were recruited and examined. The 3 most common clinical eye presentations were conjunctival disorders (60.41%), followed by lens disorders (48.12%) and scleral, corneal, iris, and ciliary body disorders (46.42%). The 3 most common conditions causing blindness (visual acuity less than 3/60 as defined by the World Health Organization) were lens disorders (45.9%), choroidal and retinal disorders (18.9%), and other disorders of the eye and adnexa (13.5%).

CONCLUSIONS

The East Timor Eye Program is an effective program that has enabled the management and treatment of various eye conditions in residents of Timor-Leste. The program set high standards for stringent and accurate data collection and ophthalmic diagnoses in a low-resource setting. Lens disorders and choroidal and retinal disorders were the most common conditions causing blindness.

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.

Prevalence and causes of visual impairment in patients seen at Nkhensani Hospital Eye Clinic, South Africa

Background

Knowledge of the prevalence and causes of visual impairment (VI) amongst hospital patients is useful in planning preventive programmes and provision of eye-care services for residents in the surrounding communities.

Aim

The aim of this study was to determine the prevalence and causes of VI amongst eye clinic patients at Nkhensani Hospital. The relationship between VI and age was also investigated.

Setting

Nkhensani Hospital in the Greater Giyani subdistrict municipality, Mopani district, Limpopo Province, South Africa.

Methods

Four hundred participants aged 6–92 years were selected for the study using a convenient sampling method. Presenting and best corrected visual acuities (VA) were measured with a LogMAR E chart. Presenting VA (PVA) in the right and left eyes and in the better eye of the patients was used to determine the prevalence of VI, low vision (LV) and blindness. Ophthalmoscope was used to diagnose the eye conditions causing VI amongst participants.

Results

The prevalence of VI based on the PVA in the right eye was 34.8% and in the left eye, the prevalence was 35.8%. There was a significant association between age of the participants and VI in the right and left eyes (p = 0.00) in each case, respectively. Based on the vision in the better eye of each patient, the prevalence of VI was 28.0% and there was a significant association between VI and age of the participants (p = 0.00). The main causes of VI were uncorrected refractive errors, cataract and glaucoma.

Conclusion

Findings in this study indicate that a large proportion of VI is preventable. Focusing on refractive error correction and surgical intervention for cataract would significantly reduce the burden of VI amongst patients utilising this hospital.

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

Purpose

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

Methods

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

Results

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

Conclusions

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

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.

Spectacle dispensing in Timor-Leste: tiered-pricing, cross-subsidization and financial viability

PURPOSE

To examine the financial viability of the Timor-Leste National Spectacle Program as it increases spectacle availability, affordability and uptake, particularly for Timor's poor.

METHODS

In rural areas, three models of ready-made spectacles were dispensed according to a tiered pricing structure of US$3.00, 1.00, 0.10 and 0.00. In addition, custom-made spectacles were available in the capital, Dili. Spectacle costs, dispensing data and income for the National Spectacle Program for 18 months from March 2007 were analyzed.

RESULTS

Rural services dispensed 3415 readymade spectacles: 47.1% to women, and 51.4% at subsidized prices, being 39.8% at US$0.10 and 11.6% free. A profit of US$1,529 was generated, mainly from the sale of US$3.00 spectacles. Women (odds ratio, OR, 1.3, 95% confidence interval, CI, 1.1-1.4) and consumers aged ≥65 years (OR 2.1; 95% CI 1.7-2.6) were more likely to receive subsidized spectacles. Urban services dispensed 2768 spectacles; mostly US$3.00 readymade (52.8%) and custom-made single vision (29.6%) units. Custom-made spectacles accounted for 36.7% of dispensing, but 73.1% of the US$12,264 urban profit. The combined rural and urban profit covered all rural costs, leaving US$2,200 to meet administration and other urban expenses.

CONCLUSION

It is instructive and encouraging that a national spectacle dispensing program in one of the ten poorest countries of the world can use tiered-pricing based on willingness-to-pay information to cover spectacle stock replacement costs and produce profit, while using cross-subsidization to provide spectacles to the poor.

prevalence and causes of blindness and low vision revisited after 5 years of eye care in Timor-Leste

PURPOSE

To estimate the 2010 prevalence and causes of blindness and low vision among Timor-Leste adults aged ≥40 years, and compare these to the results of a survey conducted 5 years previously.

METHOD

A population-based cross-sectional survey used multistage cluster random sampling proportionate to size to identify 50 clusters of 45 people each. Cause of vision loss was determined for each eye with presenting visual acuity worse than 6/18.

RESULTS

A participation rate of 89.5% (n = 2014) was achieved. The gender-age-domicile adjusted prevalence was 7.7% (95% confidence interval [CI] 6.5, 8.8) for 6/60, and 3.6% (95% CI 2.7, 4.4) for 3/60 blindness (better eye presenting vision worse than 6/60 and 3/60, respectively) among Timorese aged ≥40 years. Cataract caused most blindness (69.3% at 6/60). The population prevalence of low vision (better eye presenting vision of 6/60 or better, but worse than 6/18) was 13.6% (95%CI 12.1, 15.1), most caused by uncorrected refractive error (57.4%) or cataract (39.5%). The prevalence and causes of blindness were unchanged compared with 5 years earlier, but low vision was less common.

CONCLUSION

Unusually for a developing country, Timor-Leste has initiated a cycle of evidence-based eye care in which, although with limitations, population data are periodically available for monitoring and planning.

An estimation of the worldwide economic and health burden of visual impairment

This study aims to provide a rigorous estimate of the worldwide costs of visual impairment (VI), and the associated health burden. The study used a prevalence-based model. Prevalence rates for mild VI (visual acuity (VA) worse than 6/12 but not worse than 6/18), moderate VI (VA worse than 6/18 but not worse than 6/60) and blindness (VA worse than 6/60) were applied to population forecasts for each World Health Organisation (WHO) subregion. The limited available country cost data were extrapolated between subregions using economic and population health indicators. Age and gender subgroup population numbers were derived from United Nations' data. Costs and the health burden of VI were estimated for each world subregion using published disease prevalence rates, health care expenditures and other economic data. The study includes direct health care costs, indirect costs and the health burden of VI. The total cost of VI globally was estimated at $3 trillion in 2010, of which $2.3 trillion was direct health costs. This burden is projected to increase by approximately 20% by 2020. VI is associated with a considerable disease burden. Unless steps are taken to reduce prevalence through prevention and treatment, this burden will increase alongside global population growth.

Blindness in iraq: leading causes, target patients, and barriers to treatment

Purpose:

To define the main causes of blindness, demographic characteristics and barriers to care of blind patients attending a teaching eye hospital in Iraq.

Material and Method:

Successive new patients, 6 years of age and older, who attended three outpatients clinics at Ibn Al-Haetham Teaching Eye Hospital (IAHTEH), Baghdad, Iraq, from September 1 to November 30, 2007, were included in this study. Inclusion criterion was fulfillment of the World Health Organization's definition of blindness. The cause of blindness was identified and subjects were interviewed for collection of data on demographic characteristics and barriers to treatment.

Results:

Of 18612 consecutive patients who attended the outpatient clinics, 497 (2.7%) patients were blind. Cataract (76.1%), diabetic retinopathy (12.9%), and glaucoma (5%) were the leading causes of blindness. The majority of blind patients had low socioeconomic status and poor educational level. In cases of cataract, the most important barrier to treatment was the waiting list at the hospital (53.7%). A lack of awareness was the most important barrier to treatment for patients with diabetic retinopathy (54.7%) and glaucoma (56%).

Conclusions:

The preliminary data from our study will aid in the development of blindness prevention programs in Iraq. Priorities include decreasing waiting lists for cataract surgeries at governmental hospitals. Active health promotion programs for early detection and treatment of diabetic retinopathy and glaucoma are also warranted.

Missing X and Y: a review of participant ages in population-based eye studies

Ophthalmic population-based studies have been used to establish the frequency of eye disease and the associated environmental and genetic factors that cause vision impairment and blindness. Most of these studies have concentrated on the diseases of ageing: cataract, age-related macular degeneration, glaucoma and diabetic retinopathy. Other studies have identified eye diseases in children but few studies of young adult eye disease exist. We conducted a systematic review of the ophthalmic literature to identify potential population-based eye studies and then note the age of participants in the studies. We then summarized the disease specific to young adults to show there is a need for further research to identify eye disease in this important and often-neglected group in the community. Eighty-four large population-based studies have been conducted worldwide: 9 in North America, 2 in South America, 17 in Africa, 35 in Asia, 11 in Australia and the Pacific, 6 in Europe, 4 in the Middle East and 1 that covered 3 continents. No studies specifically examined young adults. Twenty-six per cent of studies included young adults as part of all ages examined but none of these examined a large number of young adults.

Cataract and its surgery in Fiji

BACKGROUND

To characterize cataract and its surgery among adults aged ≥40 years in Fiji.

DESIGN

Population-based cross-sectional survey using multistage cluster random sampling.

PARTICIPANTS

1381 (= 73.0% participation); eight provinces on Viti Levu.

METHODS

Interview-based questionnaire; visual acuity measured; autorefraction; dilated ocular examination.

MAIN OUTCOME MEASURES

Prevalence; predictors; surgical outcomes.

RESULTS

Being Indian (P = 0.001), elderly (P < 0.001), and previous/current smoker (P = 0.036) were predictive of at least one unoperated vision-impairing or operated cataract. Gender (P = 0.062) and diabetes (P = 0.384) were not. Unoperated cataract (predominantly nucleosclerosis) was the second most frequent (25.0%) cause of low vision (<6/18, ≥6/60) and commonest (71.1%) of blindness (<6/60). Ethnicity-gender-age-domicile adjusted and extrapolating to the Fiji population aged ≥40 years, prevalence of cataract-induced low vision and blindness were each 1.7% (95% confidence interval [CI] 1.0-2.4%). At least one eye of 4.6% and both of 1.8% participants had surgery (86.4% extracapsular). Gender (P = 0.213), age (P = 0.472) and rural/urban domicile (P = 0.895) were not predictors of surgery among those who required it in at least one eye. After intraocular lens surgery: 50.7% had pupillary posterior capsular opacification; mean spherical equivalent was -1.37 ± 1.95D (range, -6.38 to +2.25D); mean cylindrical error was 2.31 ± 1.75D (range, 0.0 to 8.75D); ≥N8 for 39.5%; ≥6/18 for 56.6%; <6/60 for 19.7%, with 2.6% no light perception. Ethnicity-gender-age-domicile adjusted and extrapolating to the Fiji population aged ≥40 years, Cataract Surgical Coverage (Person) was 47.5% (95%CI 29.2-65.8%) at <6/18, and 65.2% (95%CI 37.8-92.6%) at <6/60.

CONCLUSIONS

Fiji cataract services and outcomes compare favourably with those of neighbouring Papua New Guinea and Timor Leste.

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

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

The impact of reduced distance and near vision on the quality of life of adults in Timor-Leste

PURPOSE

To determine the independent, relative, and combined impact of reduced distance and near vision on the vision-specific quality of life (VS QOL) of adults in Timor-Leste.

DESIGN

A population-based cross-sectional eye health survey was conducted in urban and rural areas in Timor-Leste.

PARTICIPANTS

Participants were 40 years or older. Those with better eye presenting distance vision worse than 6/18, and every third participant with 6/18 or better vision, completed the VS QOL questionnaire: in total 704 of the 1414 participants.

METHODS

Distance and near visual acuities were measured and eye health was assessed. The VS QOL questionnaire administered by interview was analyzed using Rasch analysis, univariate analysis, and linear regression to determine associations between VS QOL, demographic factors, and levels of visual impairment.

MAIN OUTCOME MEASURES

The Timor-Leste VS QOL questionnaire results.

RESULTS

Rasch analysis confirmed that for participants both with and without visual impairment, the Timor-Leste VS QOL questionnaire provided a valid and reliable measure, was unidimensional, and had appropriate response categories. There was a consistent pattern of deterioration in VS QOL as vision worsened: for each category of distance- and near-vision impairment, there was an independent and significant change in Timor-Leste VS QOL scores between no visual impairment and either mild, moderate, or severe impairment (P < 0.05). Combined distance- and near-vision impairment was associated with a greater impact on VS QOL than categories separately, the impact of severe distance- and near-vision impairment being the greatest and clinically significant: -3.05 (95% confidence interval [CI], -3.60 to -2.49; P<0.05; and 95% CI, <-1.0). Distance vision (37.2%) contributed relatively more than near vision (4.7%) to the total variance in VS QOL (41.9%). Older people, those not married, not literate, and rural dwellers had significantly worse Timor-Leste VS QOL scores (P < 0.05).

CONCLUSIONS

This study provides evidence of independent dose-response relationships between distance- and near-vision impairment and poorer VS QOL. Distance-vision impairment had a relatively larger impact on VS QOL than near-vision impairment. Combined distance- and near-vision impairment was associated with a greater impact on VS QOL compared with the independent impact of distance- or near-vision impairment at similar levels.

Correction of refractive error and presbyopia in Timor-Leste

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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