Cataract, visual impairment and long-term mortality in a rural cohort in India: the Andhra Pradesh Eye Disease Study

The association between disability and all-cause mortality in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

There are 1·3 billion people with disabilities globally. On average, they have poorer health than their non-disabled peers, but the extent of increased risk of premature mortality is unknown. We aimed to systematically review the association between disability and mortality in low-income and middle-income countries (LMICs).

METHODS

We searched MEDLINE, Global Health, PsycINFO, and EMBASE from Jan 1, 1990 to Nov 14, 2022. Longitudinal epidemiological studies in any language with a comparator group that measured the association between disability and all-cause mortality in people of any age were eligible for inclusion. Two reviewers independently assessed study eligibility, extracted data, and assessed risk of bias. We used a random-effects meta-analysis to calculate the pooled hazard ratio (HR) for all-cause mortality by disability status. We then conducted meta-analyses separately for different impairment and age groups.

FINDINGS

We identified 6146 unique articles, of which 70 studies (81 cohorts) were included in the systematic review, from 22 countries. There was variability in the methods used to assess and report disability and mortality. The meta-analysis included 54 studies, representing 62 cohorts (comprising 270 571 people with disabilities). Pooled HRs for all-cause mortality were 2·02 (95% CI 1·77-2·30) for people with disabilities versus those without disabilities, with high heterogeneity between studies (τ2=0·23, I2=98%). This association varied by impairment type: from 1·36 (1·17-1·57) for visual impairment to 3·95 (1·60-9·74) for multiple impairments. The association was highest for children younger than 18 years (4·46, [3·01-6·59]) and lower in people aged 15-49 years (2·45 [1·21-4·97]) and people older than 60 years (1·97 [1·65-2·36]).

INTERPRETATION

People with disabilities had a two-fold higher mortality rate than people without disabilities in LMICs. Interventions are needed to improve the health of people with disabilities and reduce their higher mortality rate.

FUNDING

UK National Institute for Health and Care Research; and UK Foreign, Commonwealth and Development Office.

Evaluation and model to achieve sex parity in cataract surgical coverage in Theni district, India

BACKGROUND/AIMS

To propose an approach to determine the target ratio of cataract surgical rates (CSRs) of female to male subpopulations to increase sex parity in cataract surgical coverage (CSC), based on the sex gap in cataract burden and incidence, and demonstrate its application to Theni district, India.

METHODS

A population-based longitudinal study between January 2016 and April 2018. We recruited 24 327 participants using random cluster sampling. We conducted detailed eye examinations of 7087 participants aged ≥40 years (4098 females, 2989 males). We fit exponential models to the age-specific and sex-specific cataract burden and estimated annual incidence rates. We developed a spreadsheet-based planning tool to compute the target CSR ratio of female to male subpopulations.

RESULTS

Among those aged ≥40 years, cataract burden was 21.4% for females and 17.5% for males (p<0.05). CSC was 73.9% for females versus 78.6% for males (p<0.05), with an effective CSC of 52.6% for females versus 57.6% for males (p<0.05). Treating only incident cataracts each year requires a target CSR ratio of female to male subpopulations of 1.30, while addressing in addition 10% of the coverage backlog for females and 5% for males requires a target CSR ratio of 1.48.

CONCLUSIONS

The female population in Theni district, as in many low-income and middle-income countries, bears a higher cataract burden and lower CSC. To enhance sex parity in coverage, both the higher number of annual incident cataracts and the larger backlog in females will need to be addressed.

Incidence of primary open angle glaucoma in the Andhra Pradesh Eye Disease Study (APEDS)

BACKGROUND

To report 15-year incidence rate of primary open angle glaucoma (POAG) in the Andhra Pradesh Eye Disease Study (APEDS).

METHODS

A population-based longitudinal study was carried out at three rural study sites. Phakic participants aged ≥40 years who participated at baseline (APEDS I) and the mean 15-year follow-up visit (APEDS III) were included. A comprehensive ophthalmic examination was performed on all participants. Mean intraocular pressure (IOP) was average of IOPs of right and left eyes. The definition of glaucoma was based on the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification. The main outcome measure was incidence of POAG during the follow-up period in participants without glaucoma or suspicion of glaucoma at baseline.

RESULTS

Data from the available and eligible participants from the original cohort (1241/2790; 44.4%) were analysed. The mean age (standard deviation) of participants at baseline was 50.2 (8.1) years; 580 (46.7%) were men. Thirty-six participants developed POAG [bilateral in 17 (47.2%)] over 15 years. The incidence rate of POAG per 100-person years (95% confidence interval) was 2.83 (2.6, 3.08). Compared to baseline, the reduction in mean IOP [median (range) mm Hg] was -0.75 (-7.5, 9) in participants with incident POAG and -2.5 (-14.5, 14.5) in those without. The inter-visit difference in mean IOP was a significant risk factor on logistic regression analysis.

CONCLUSION

We report the long-term incidence of POAG in rural India. A longitudinal change in IOP, specifically a less pronounced reduction in IOP with increasing age, was a novel risk factor.

Enzymatic and biochemical properties of lens in age-related cataract versus diabetic cataract: A narrative review

Cataract is the leading cause of blindness worldwide. There is an increased incidence of cataract formation in the diabetic population due to several factors. Diabetes mellitus accelerates the development of cataract. Oxidative stress results in most of the diabetic complications including diabetic cataract. Oxidative stress leading to the expression of various enzymes has also been proven as crucial for cataractous changes in the lens in old age. A narrative review was undertaken to investigate the expression of different biochemical parameters as well as enzymes in diabetic and senile cataracts. Identification of these parameters is crucial for the prevention and treatment of blindness. Combinations of MeSH terms and key words were used to do literature search in PubMed. The search resulted 35 articles and among them, 13 were relevant to the topic and were included in synthesis of results. Seventeen different types of enzymes were identified in the senile and diabetic cataracts. Seven biochemical parameters were also identified. Alteration in biochemical parameters and expression of enzymes were comparable. Majority of the parameters were raised or altered in diabetic cataract compared to senile cataract.

Self-reported cataract surgery and 10-year all-cause and cause-specific mortality: findings from the National Health and Nutrition Examination Survey

PURPOSE

To investigate the association of self-reported cataract surgery with all-cause and cause-specific mortality using a large-scale population-based sample.

METHODS

Data from the 1999-2008 cycles of the National Health and Nutrition Examination Survey were used. A self-reported history of cataract surgery was considered a surrogate for the presence of clinically significant cataract surgery. Mortality data were ascertained from National Death Index records. Hazard ratios (HRs) and 95% confidence intervals (CIs) for survival were estimated using Cox proportional hazards regression models.

RESULTS

A total of 14 918 participants were included in the analysis. During a median follow-up of 10.8 (Interquartile range, IQR, 8.25-13.7) years, 3966 (19.1%) participants died. Participants with self-reported cataract surgery were more likely to die from all causes and specific causes (vascular disease, cancer, accident, Alzheimer's disease, respiratory disease, renal disease and others) compared with those without (all Ps <0.05). The association between self-reported cataract surgery and all-cause mortality remained significant after multiple adjustments (HR=1.13; 95% CI 1.01 to 1.26). For cause-specific mortality, multivariable Cox models showed that self-reported cataract surgery predicted a 36% higher risk of vascular-related mortality (HR=1.36; 95% CI 1.01 to 1.82). The association with other specific causes of mortality did not reach statistical significance after multiple adjustments.

CONCLUSIONS

This study found significant associations of self-reported cataract surgery with all-cause and vascular mortalities. Our findings provide potential insights into the pathogenic pathways underlying cataract.

Opium Use and the Risk of Cataract: a Hospital-based, Group-matched, Case-control Study in Iran

PURPOSE

Cataract is the most prevalent cause of reversible blindness worldwide. Although studies have identified risk factors for cataract, its association with opium use has not been studied. This study aimed to evaluate the association between opium use and cataract in Iran in 2020.

METHODS

In a hospital-based, group-matched case-control study in Kerman, a city in southeast Iran, 160 new cases of cataract and 320 controls without cataract underwent ophthalmological examination and were interviewed. Logistic regression models tested the association between cataract and history of opium use, adjusting for demographic characteristics and history of hypertension, coronary heart disease, renal disease, smoking, alcohol use, and unprotected sun exposure.

RESULTS

After controlling for potential confounders, opium use increased the odds of cataract, exhibiting a dose-response relationship. The adjusted odds ratio (aOR) for mild use was 1.44 (95% confidence intervals [CI] 0.80-2.58), and 2.10 (95% CI 1.04-4.25) for heavy use. Exposure to opium juice use further increased the odds of cataract (aOR 2.24, 95% CI 1.00-5.10). Other significant associations with cataract were lower education level (aOR 5.46, 95% CI 2.45-11.29), being unmarried (aOR 2.88, 95% CI 1.65-5.00), both underweight (BMI <18.5, aOR 5.27, 95% CI 2.02-13.70) and overweight (BMI >25, aOR 1.82, 95% CI 1.15-2.87), and family history of cataract (aOR 2.07, 95% CI 1.32-3.23).

CONCLUSION

Our study provides evidence that opium use could increase the odds of cataract. Results also support the association of cataract with other modifiable risk factors, such as very low and high BMI and unprotected sun exposure.

Use of unclean cooking fuels and visual impairment of older adults in India: A nationally representative population-based study

Despite widespread use of unclean cooking fuels (UCF) in India, evidence from nationally representative data on its association with visual impairment was lacking. We used a population-based nationwide survey of adults aged 45 years and older that included reported UCF and measured visual impairment. We estimated that 44.8% (95% CI: 42.6, 47.1) of older adults in India lived in households that used UCF. Age- and sex-adjusted prevalence of visual impairment was estimated to be 33.0% (95% CI: 31.0, 34.9) in the older population that did not use UCF and 9.0 percentage points (pp) (95% CI: 8.9, 9.1) higher among those who did. Among those who used UCF, age- and sex-adjusted prevalence of low distance vision was 4.3 pp (95% CI: 4.2, 4.4) higher, prevalence of low near vision was 8.0 pp (95% CI: 7.9, 8.1) higher, and prevalence of blindness was 1.0 pp (95% CI: 0.9, 1.0) higher. After controlling for a rich array of sociodemographic characteristics and state fixed effects, we estimated that use of UCF was associated with higher prevalence of visual impairment by 3.2 pp (95% CI: 1.4, 5.0), low distance vision by 1.8 pp (95% CI: 0.7, 2.9), and low near vision by 3.2 pp (95% CI: 1.3, 5.0). Doubly robust estimates of these differences were slightly larger. Blindness was not significantly partially associated with use of UCF (95% CI: -0.4, 0.6). We did not find support for the hypotheses that the visual impairment risk associated with use of UCF was even larger for females and in households without a separate kitchen or ventilation. The older population of India is highly reliant on UCF that is very strongly associated with visual impairment. Impaired vision should not be overlooked among the harms associated with UCF.

Senile Cataract in Patients with Diabetes with and Without Diabetic Retinopathy: A Community-Based Comparative Study

Aim

We compare the incidence rates of cataract in persons with diabetes with and without diabetic retinopathy in Saudi Arabia, for the first time. In addition, we explored the role of new factor, diabetes age of onset and several other known factors.

Methods

In a community-based cross-sectional study, 334 persons with diabetes type 2 were randomly selected from a diabetic register. Detailed history and comprehensive ophthalmic examination was done at an eye clinic. Body Mass Index, blood pressure and glycosylated hemoglobin were also recorded.

Results

In 668 eyes, cataract and diabetic retinopathy were present in 35.5% and 32.2%, respectively. Diabetic retinopathy, age, duration of diabetes and systolic BP were found to be independent risk factors for cataract. Whereas, gender, BMI, HbA1c use of insulin and diastolic BP have no significant association with cataract. Persons with cataract had significantly higher age of onset of diabetes. Most of the cataracts were cortical followed by PSC, while minority were nuclear.

Conclusion

DR is an independent risk factor of developing cataract in persons with diabetes. Others are age, duration of DM and hypertension. Age-of-onset of DM is a new factor we report it to be significantly associated with cataract.

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

PURPOSE

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

DESIGN

Prospective cohort study with meta-analysis.

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fifteen-Year Incidence Rate of Primary Angle Closure Disease in the Andhra Pradesh Eye Disease Study

PURPOSE

To report on the 15-year incidence of primary angle closure disease (PACD) among participants aged ≥40 years in rural southern India DESIGN: Population-based longitudinal incidence rate study METHODS: Setting: 3 rural study centres.

STUDY POPULATION

Phakic participants aged ≥40 years who participated in both examination time points.

OBSERVATION PROCEDURES

All participants at the baseline and at the mean 15-year follow-up visit underwent a detailed interview, anthropometry, blood pressure measurement, and comprehensive eye examination. Automated perimetry was attempted based on predefined criteria. Main outcome measures included development of any form of PACD, as defined by the International Society for Geographical and Epidemiological Ophthalmology (ISGEO), during the follow-up period in phakic participants, who did not have the disease at baseline.

RESULTS

We analyzed data obtained from 1,197 (81.4% out of available 1,470) participants to calculate the incidence of the disease. The mean age (standard deviation) of the study participants at the baseline was 50.2 (8.1) years, with 670 male (45.5%) and 800 female (54.4%) participants. The incidence rate per 100 person-years (95% confidence interval) for primary angle closure suspect, primary angle closure, and primary angle closure glaucoma was 8.8 (8.4, 9.2), 6.2 (5.9, 6.6), and 1.6 (1.4, 1.8), respectively. Thus, the incidence of all forms of PACD was 16.4 (15.9, 17) per 100 person-years. On logistic regression analysis, female gender was a significant risk factor whereas presence of myopia was protective.

CONCLUSIONS

This study reports long-term incidence of PACD from rural India. It has implications for eye health care policies, strategies, and planning.

Association between vision impairment and mortality: a systematic review and meta-analysis

BACKGROUND

The number of individuals with vision impairment worldwide is increasing because of an ageing population. We aimed to systematically identify studies describing the association between vision impairment and mortality, and to assess the association between vision impairment and all-cause mortality.

METHODS

For this systematic review and meta-analysis, we searched MEDLINE (Ovid), Embase, and Global Health database on Feb 1, 2020, for studies published in English between database inception and Feb 1, 2020. We included prospective and retrospective cohort studies that measured the association between vision impairment and all-cause mortality in people aged 40 years or older who were followed up for 1 year or more. In a protocol amendment, we also included randomised controlled trials that met the same criteria as for cohort studies, in which the association between visual impairment and mortality was independent of the study intervention. Studies that did not report age-adjusted mortality data, or that focused only on populations with specific health conditions were excluded. Two reviewers independently assessed study eligibility, extracted the data, and assessed risk of bias. We graded the overall certainty of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations framework. We did a random-effects meta-analysis to calculate pooled maximally adjusted hazard ratios (HRs) for all-cause mortality for individuals with a visual acuity of <6/12 versus those with ≥6/12; <6/18 versus those with ≥6/18; <6/60 versus those with ≥6/18; and <6/60 versus those with ≥6/60.

FINDINGS

Our searches identified 3845 articles, of which 28 studies, representing 30 cohorts (446 088 participants) from 12 countries, were included in the systematic review. The meta-analysis included 17 studies, representing 18 cohorts (47 998 participants). There was variability in the methods used to assess and report vision impairment. Pooled HRs for all-cause mortality were 1·29 (95% CI 1·20-1·39) for visual acuity <6/12 versus ≥6/12, with low heterogeneity between studies (n=15; τ2=0·01, I2=31·46%); 1·43 (1·22-1·68) for visual acuity <6/18 versus ≥6/18, with low heterogeneity between studies (n=2; τ2=0·0, I2=0·0%); 1·89 (1·45-2·47) for visual acuity <6/60 versus ≥6/18 (n=1); and 1·02 (0·79-1·32) for visual acuity <6/60 versus ≥6/60 (n=2; τ2=0·02, I2=25·04%). Three studies received an assessment of low risk of bias across all six domains, and six studies had a high risk of bias in one or more domains. Effect sizes were greater for studies that used best-corrected visual acuity compared with those that used presenting visual acuity as the vision assessment method (p=0·0055), but the effect sizes did not vary in terms of risk of bias, study design, or participant-level factors (ie, age). We judged the evidence to be of moderate certainty.

INTERPRETATION

The hazard for all-cause mortality was higher in people with vision impairment compared with those that had normal vision or mild vision impairment, and the magnitude of this effect increased with more severe vision impairment. These findings have implications for promoting healthy longevity and achieving the Sustainable Development Goals.

FUNDING

Wellcome Trust, Commonwealth Scholarship Commission, National Institutes of Health, Research to Prevent Blindness, the Queen Elizabeth Diamond Jubilee Trust, Moorfields Eye Charity, National Institute for Health Research, Moorfields Biomedical Research Centre, Sightsavers, the Fred Hollows Foundation, the Seva Foundation, the British Council for the Prevention of Blindness, and Christian Blind Mission.

Incidence, Incident Causes, and Risk Factors of Visual Impairment and Blindness in a Rural Population in India: 15-Year Follow-up of the Andhra Pradesh Eye Disease Study

PURPOSE

To report 15-year incidence rate of visual loss (blindness and visual impairment [VI]), causes, and risk factors for participants in Andhra Pradesh Eye Disease Study III (APEDS III).

DESIGN

Population-based cohort study.

METHODS

From 2012 to 2016, all rural participants were interviewed and underwent a comprehensive eye examination, including dilated fundus examination and imaging. Presenting visual acuity (PVA) and best-corrected visual acuity (BCVA) were measured using a standard logarithm of Minimum Angle of Resolution chart at 3 meters. World Health Organization (WHO) and United States of America (USA) categories of VI and blindness were used. Incident visual loss was defined as the development of or worsening of visual loss of one or more categories.

RESULTS

In APEDS I, 7,771 rural participants were examined using stratified, random-cluster systematic sampling; in APEDS III, 5,395 participants (69.4% of rural or 52.4% of total participants) were re-examined. Using WHO categories, the crude incidence rate of any visual loss based on PVA and BCVA were 14.6 (95% confidence interval [CI]:13.6-15.7) and 6.3 (95% CI: 6.1-6.4) per 100 person-years, respectively. Using USA criteria, the values were 22.6 (95% CI: 22.3-23.0) and 10.6 (95% CI: 10.3-10.8) per 100 person-years, respectively. More than 90% of visual loss was attributable to cataract and uncorrected refractive error. Using WHO categories, significant independent risk factors for the incident visual loss were increasing age, female gender, illiteracy, past or current smoker, and current use of alcohol. Using the USA definition, an additional risk factor was lower level of education.

CONCLUSIONS

The high incidence likely reflects poor access to eye care in this population, which needs to be taken into account when planning eye care programs.

Cataract risk stratification and prioritisation protocol in the COVID-19 era

Background

The COVID-19 pandemic halted non-emergency surgery across Scotland. Measures to mitigate the risks of transmitting COVID-19 are creating significant challenges to restarting all surgical services safely. We describe the development of a risk stratification tool to prioritise patients for cataract surgery taking account both specific risk factors for poor outcome from COVID-19 infection as well as surgical ‘need’. In addition we report the demographics and comorbidities of patients on our waiting list.

Methods

A prospective case review of electronic records was performed. A risk stratification tool was developed based on review of available literature on systemic risk factors for poor outcome from COVID-19 infection as well as a surgical ‘need’ score. Scores derived from the tool were used to generate 6 risk profile groups to allow prioritised allocation of surgery.

Results

There were 744 patients awaiting cataract surgery of which 66 (8.9 %) patients were ‘shielding’. One hundred and thirty-two (19.5 %) patients had no systemic comorbidities, 218 (32.1 %) patients had 1 relevant systemic comorbidity and 316 (46.5 %) patients had 2 or more comorbidities. Five hundred and ninety patients (88.7 %) did not have significant ocular comorbidities. Using the risk stratification tool, 171 (23 %) patients were allocated in the highest 3 priority stages. Given an aging cohort with associated increase in number of systemic comorbidities, the majority of patients were in the lower priority stages 4 to 6.

Conclusions

COVID-19 has created an urgent challenge to deal safely with cataract surgery waiting lists. This has driven the need for a prompt and pragmatic change to the way we assess risks and benefits of a previously regarded as low-risk intervention. This is further complicated by the majority of patients awaiting cataract surgery being elderly with comorbidities and at higher risk of mortality related to COVID-19. We present a pragmatic method of risk stratifying patients on waiting lists, blending an evidence-based objective assessment of risk and patient need combined with an element of shared decision-making. This has facilitated safe and successful restarting of our cataract service.

In Vivo Quasi-Elastic Light Scattering Eye Scanner Detects Molecular Aging in Humans

The absence of clinical tools to evaluate individual variation in the pace of aging represents a major impediment to understanding aging and maximizing health throughout life. The human lens is an ideal tissue for quantitative assessment of molecular aging in vivo. Long-lived proteins in lens fiber cells are expressed during fetal life, do not undergo turnover, accumulate molecular alterations throughout life, and are optically accessible in vivo. We used quasi-elastic light scattering (QLS) to measure age-dependent signals in lenses of healthy human subjects. Age-dependent QLS signal changes detected in vivo recapitulated time-dependent changes in hydrodynamic radius, protein polydispersity, and supramolecular order of human lens proteins during long-term incubation (~1 year) and in response to sustained oxidation (~2.5 months) in vitro. Our findings demonstrate that QLS analysis of human lens proteins provides a practical technique for noninvasive assessment of molecular aging in vivo.

All-cause mortality and three aspects of social relationships: an eight-year follow-up of older adults from one entire Korean village

Various aspects of social relationships have been examined as risk factors for mortality. In particular, most research has focused on either loneliness or social disengagement. We aimed to extend the current research by adding a group-level segregation measure utilizing the whole social network of one entire village in South Korea. The analyses were based on the Korean Social Life, Health and Aging Project data collected over eight years across five waves. Of the 679 old adults who participated throughout the entire project (to wave 5), 63 were confirmed as deceased. All three aspects of social relationships examined, loneliness, social disengagement, and group-level segregation, were associated with mortality in the traditional Cox proportional hazard model without considering health-related time-varying covariates. However, a Cox marginal structural model, a counterfactual statistical measure that is designed to control for censoring bias due to sample attrition over the eight years and time-varying confounding variables, revealed that only group-level segregation was associated with mortality. Our results strongly suggest that more attention is needed on group-level segregation for mortality studies, as well as on well-known individual-level risk factors, including social disengagement and loneliness. All methods were carried out in accordance with relevant guidelines and regulations.

Comprehensive eye care - Issues, challenges, and way forward

As we move from a disease-specific care model toward comprehensive eye care (CEC), there is a need for a more holistic and integrated approach involving the health system. It should encompass not only treatment, but also prevention, promotion, and rehabilitation of incurable blindness. Although a few models already exist, the majority of health systems still face the challenges in the implementation of CEC, mainly due to political, economic, and logistic barriers. Shortage of eye care human resources, lack of educational skills, paucity of funds, limited access to instrumentation and treatment modalities, poor outreach, lack of transportation, and fear of surgery represent the major barriers to its large-scale diffusion. In most low- and middle-income countries, primary eye care services are defective and are inadequately integrated into primary health care and national health systems. Social, economic, and demographic factors such as age, gender, place of residence, personal incomes, ethnicity, political status, and health status also reduce the potential of success of any intervention. This article highlights these issues and demonstrates the way forward to address them by strengthening the health system as well as leveraging technological innovations to facilitate further care.

Association between Age-related Cataract and Mortality in Sweden: A Long-term Population-based Follow-up Study

PURPOSE

To assess the relationship of age-related cataract with all-cause mortality in a Swedish population.

METHODS

Cox regression analyses were performed in a cohort of 746 residents 65-74 years of age, examined in a population survey in the rural district of Tierp, Sweden, 1984-86. To expand the sample size, 1,071 people were recruited by means of glaucoma case records established at the Eye Department in Tierp from 1978 to 2007. In this way, the cohort comprised 1,817 subjects, representing nearly 27,000 person-years at risk. The presence of cataract was determined based on retroillumination with lens opacities evident on slit-lamp examination. Information on deaths was obtained from the local population register.

RESULTS

By the conclusion of the study in April 2020, 1,633 deaths had been reported. Of these cases, 694 were affected by lens opacities or had history of cataract surgery at baseline. In multivariate analysis, including cataract, age, sex, smoking habits, cancer, diabetes, hypertension and ischemic heart disease, no association was found between cataract and mortality (hazard ratio 0.99; 95% confidence interval 0.90-1.10). Adjustment for participation in the population survey had no effect on the estimate.

CONCLUSION

In this long-term follow-up study of subjects 65-74-years-old in Sweden, cataract was not associated with all-cause mortality.

Visual impairment and ten-year mortality: the Liwan Eye Study

OBJECTIVES

To explore associations between visual impairment (VI) and mortality in an adult population in urban China.

METHODS

The Liwan Eye Study was a population-based prevalence survey conducted in Guangzhou, Southern China. The baseline examination was carried out in 2003. All baseline participants were invited for the 10-year follow-up visit. VI was defined as the visual acuity of 20/40 or worse in the better-seeing eye with habitual correction if worn. Correctable VI was defined as the VI correctable to 20/40 or better by subjective refraction, and non-correctable VI was defined as the VI correctable to worse than 20/40. Mortality rates were compared using the log-rank test and Cox proportional hazards regression models.

RESULTS

Of the 1399 participants (mean age: 65.3 ± 9.93 years; 56.4% female) with available baseline visual acuity measurement, 320 participants (22.9%) had VI. After 10 years, 314 (22.4%) participants died. Visually impaired participants had a significantly increased 10-year mortality compared with those without VI (40.0% vs. 17.2%, P < 0.05). After adjusting for age, gender, income, educational attainment, BMI, history of diabetes and hypertension, both VI (HR, 1.55; 95% CI, 1.14-2.11) and non-correctable VI (HR, 2.72; 95% CI, 1.86-3.98) were significantly associated with poorer survival, while correctable VI (HR, 0.99; 95% CI, 0.66-1.49) was not an independent risk factor for 10-year mortality.

CONCLUSIONS

Our findings that VI, particularly non-correctable VI, predicting poorer survival may imply the underlying mechanism behind VI-mortality association and reinforce the importance of preventing and treating disabling ocular diseases to prevent premature mortality in the elderly.

The prevalence and causes of visual impairment among children in Kenya - the Kenya eye study

Background

Visual impairment is the partial or complete loss of vision in which the presenting visual acuity lie between 6/18-no perceptions of light. In Kenya, little attention has been directed towards children vision and causes of visual impairment. Therefore, this study was designed to investigate the prevalence and causes of visual impairment in the children population of Kenya.

Methods

This cross-sectional population-based study included 3400 (1800, 52.9% female) randomly selected children with a mean age of 12 ± 2 years (range 5–16 years). Visual acuity was taken using Snellens chart at 6 m. Anterior and posterior segment was assessed using slit lamp and indirect ophthalmoscope. The World Health Organization definition formed the baseline for calculating the mean prevalence of visual impairment.

Results

Visual acuity measurements were available for 3240 (95.3%) participants. The mean prevalence of visual impairment based on pin-hole value was 1.7 ± 0.3% using World Health Organization definition. The prevalence of visual impairment based on presenting visual acuity value was 2.4 ± 0.7% using the World Health Organization definition. Multivariate analysis demonstrated that the presence of visual impairment on pin-hole increased significantly with increasing age (odds ratio 1.230, P = .021) and uncorrected refractive error (odds ratio 0.834, P = .032) according to World Health Organization definition. Cases of uncorrected refractive error remained the major cause for presenting visual impairment. Causes of visual impairment due to presenting visual acuity were nystagmus (14%), amblyopia (24%) and uncorrected refractive error (62%).

Conclusion

The prevalence of visual impairment in Kenya is associated with age. Uncorrected refractive error remains the major causes of visual impairment.

Fifteen-year incidence rate and risk factors of pterygium in the Southern Indian state of Andhra Pradesh

PURPOSE

To report 15-year incidence rate and associated risk factors of pterygium among people aged 30 years and above at baseline in the rural clusters of longitudinal Andhra Pradesh Eye Disease Study (APEDS III).

METHODS

The baseline APEDS I included 7771 participants of which 6447 (83%) were traced and 5395 (83.7%) were re-examined in APEDS III. To estimate the incidence of pterygium, we selected participants who were 30 years and above at baseline (4188), of which 2976 were traced and 2627 (88.3%) were examined, and based on inclusion criteria, 2290 participants were included in the study. The incidence rate of pterygium was defined as the proportion of people free of pterygium at baseline who had developed the condition at 15-year follow-up (range 13-17 years). Univariate and multivariable analyses for risk factors were undertaken.

RESULTS

The sex-adjusted incidence rate of pterygium was 25.2 per 100 person-years (95% CI 24.8 to 25.7) which was significantly higher for men than women (26.3 per 100 person-years (95% CI 25.6 to 27.0) and 24.7 (95% CI 24.1 to 25.3) respectively). At the multivariable analysis, male gender (RR: 1.35, 95% CI 1.0 to 1.83), no formal education (RR: 2.46, 95% CI 1.22 to 4.93), outdoor occupation (RR: 1.47, 95% CI 1.14 to 1.9) and lower body mass index (BMI) (<18.5) (RR: 1.25, 95% CI 1.02 to 1.55) were associated with increased risk of pterygium.

CONCLUSIONS

The overall incidence rate of pterygium was high in this rural population, especially in men and those engaged in outdoor activities, lack of formal education and with lower BMI. It is likely that greater exposure to ultraviolet light is a major contributing factor, thus warranting preventive strategies.

Uncorrected refractive errors for distance among the residents in 'homes for the aged' in South India-The Hyderabad Ocular Morbidity in Elderly Study (HOMES)

PURPOSE

To investigate the prevalence and risk factors of Uncorrected Refractive Errors (URE) for distance in elderly residents in 'homes for the aged' in Hyderabad, India.

METHODS

Individuals aged ≥60 years and residing in 'homes for the aged' in Hyderabad, India for a minimum of 1 month and providing consent for participation were recruited. All participants underwent visual acuity assessment, refraction, slit lamp biomicroscopy, intraocular pressure measurement, fundus examination, and retinal imaging. Monocular presenting visual acuity was recorded using a logMAR chart. Objective and subjective refraction were performed, and best-corrected visual acuity was recorded. URE was defined as presenting visual acuity worse than 6/12 but improving to 6/12 or better with refraction. Univariable and multivariable logistic regression analyses were used to assess the risk factors associated with URE.

RESULTS

In total, 1 513 elderly participants were enumerated from 41 homes of which 1 182 participants (78.1%) were examined. The mean age of participants was 75.0 years (standard deviation 8.8 years; range: 60-108 years). 35.4% of those examined were men and 20.3% had no formal education. The prevalence of URE was 13.5% (95% CI: 11.5-15.5; n = 159). On applying multiple logistic regression analysis, compared to those living in private homes, the odds of URE were significantly higher among the elderly living in the aided homes (OR: 1.65; 95% CI: 1.11-2.43) and free homes (OR: 1.67; 95% CI: 1.00-2.80). As compared to those who reported having an eye examination in the last 3 years, the odds of URE were higher among those who never had an eye examination in the last three years (OR: 1.51; 95% CI: 1.07-2.14). Similarly, those who had unilateral cataract surgery (OR: 1.80; 95% CI: 1.10-2.93) or bilateral cataract surgery (1.69; 95% CI: 1.10-2.56) had higher odds of URE compared to those elderly who were not operated for cataract. Gender, self-report of diabetes, and education were not associated with URE.

CONCLUSIONS

A large burden of URE was found among the residents in the 'homes for the aged' in Hyderabad, India which could be addressed with a pair of glasses. Over 40% of the residents never had an eye examination in the last three years, which indicates poor utilisation of eye care services by the elderly. Regular eye examinations and provision of spectacles are needed to address needless URE for distance among the elderly in residential care in India.

Age-related cataract and 10-year mortality: the Liwan Eye Study

PURPOSE

To explore the association between age-related cataract and 10-year mortality in an adult population in urban China.

METHODS

A total of 1405 participants aged 50 years or older were examined at baseline in the Guangzhou Liwan Eye Study. All participants were invited to attend a 10-year follow-up visit. Cataract cases were defined as either having visible lens opacity confirmed with direct ophthalmoscope under pupil dilation or previous history of cataract surgery. Visual impairment (VI) was defined as a visual acuity of 20/40 or worse in the better-seeing eye with habitual correction if worn. Body mass index (BMI) was based on anthropometric data. A brief questionnaire regarding family income, educational attainment and medical history of systemic disease was administered. Mortality rates were compared using the log-rank test and Cox proportional hazards regression models.

RESULTS

Among 1405 participants examined at baseline, 957 participants (68.1%) had visible lens opacity or history of cataract surgery. After 10 years, 320 (22.8%) participants died. The 10-year mortality rate was significantly higher in participants with cataract than in those without (30.1% versus 7.14%, log-rank p < 0.05). After adjusting for age, gender, family income, educational attainment, BMI, history of diabetes and hypertension and presence of VI, presence of cataract predicted a nearly threefold increase in the risk of mortality (HR, 2.99; 95% CI, 1.89-4.71).

CONCLUSIONS

Our findings that age-related cataract is a predictor for poorer survival compared to those without may imply that cataract is a biomarker of ageing and frailty.

An Enhanced Approach for Economic Evaluation of Long-Term Benefits of School-Based Health Promotion Programs

Chronic diseases constitute a tremendous public health burden globally. Poor nutrition, inactive lifestyles, and obesity are established independent risk factors for chronic diseases. Public health decision-makers are in desperate need of effective and cost-effective programs that prevent chronic diseases. To date, most economic evaluations consider the effect of these programs on body weight, without considering their effects on other risk factors (nutrition and physical activity). We propose an economic evaluation approach that considers program effects on multiple risk factors rather than on a single risk factor. For demonstration, we developed an enhanced model that incorporates health promotion program effects on four risk factors (weight status, physical activity, and fruit and vegetable consumption). Relative to this enhanced model, a model that considered only the effect on weight status produced incremental cost-effectiveness ratio (ICER) estimates for quality-adjusted life years that were 1% to 43% higher, and ICER estimates for years with chronic disease prevented that were 1% to 26% higher. The corresponding estimates for return on investment were 1% to 20% lower. To avoid an underestimation of the economic benefits of chronic disease prevention programs, we recommend economic evaluations consider program effects on multiple risk factors.

Mortality and causes of death in a population with blindness in Korea: A longitudinal follow-up study using a national sample cohort

The influence of visual impairment and blindness on the risk of mortality has been reported in diverse cohort studies. However, the results reported have varied from nonsignificant to significant associations. In the present study, we evaluated the influence of blindness on the risk of mortality from 2002 to 2013 using a longitudinal database with a national sample cohort provided by the Korean National Health Insurance Service. Of a total of 1,125,691 subjects, 1,279 subjects who were registered as blind were enrolled, and 5,116 control participants were matched at a 1:4 ratio for age, sex, income, region of residence, and medical histories of hypertension, diabetes mellitus and dyslipidemia. The life/death information contained in this dataset was used for the analysis; this information was originally recorded by the medical doctors on the death certificates of the participants. The percentage of total deaths during the mean follow-up period of 111.0 ± 41.6 months was 28.1% in the blindness group and 19.7% in the matched control group. The risk of mortality was significantly higher in the blindness group than in the control group according to the Cox proportional hazards model with additional adjustments for ischemic heart disease, stroke, and depression (adjusted hazard ratio [HR] of mortality = 1.54, 95% confidence interval [CI] = 1.37–1.74, P < 0.001). In the subgroup analyses, the adjusted HRs for mortality were significantly higher in the blindness group than in the control group regardless of age (young defined as <60 years old vs old defined as ≥60 years old) and sex. The percentage of death due to metabolic diseases and genitourinary diseases was higher in the blindness group than in the matched control group.

Association of Age-Related Macular Degeneration With Risk of All-Cause and Specific-Cause Mortality in the National Health and Nutrition Examination Survey, 2005 to 2008

Question

What is the association of age-related macular degeneration with mortality outcomes among older adults?

Findings

In this cohort study of 5603 participants 40 years or older, only late age-related macular degeneration was associated with more than a doubling of all-cause mortality and more than 3-fold higher risk of mortality not due to cardiovascular disease and cancer.

Meaning

The association of late age-related macular degeneration and poor survival may shed light on mechanisms underlying the disease, indicating that late age-related macular degeneration may be a marker of frailty and aging or may be due to residual confounding factors indicative of aging.

Importance

Age-related macular degeneration (AMD) is the leading cause of irreversible visual impairment and blindness in the United States if subretinal neovascularization is left untreated. Knowledge of the association between AMD and survival is informative for underlying mechanisms of AMD.

Objective

To examine the association between AMD and risk of all-cause and specific-cause mortality in a representative US sample.

Design, Setting, and Participants

This population-based prospective cohort study included 5603 participants 40 years or older who responded to the National Health and Nutrition Examination Survey (NHANES) in the 2005-2008 phase. Retinal photographs were graded as early, late, or no AMD. All analyses accounted for the complex and stratified design of NHANES with weighted data. Risks of all-cause mortality were assessed with Cox proportional hazards regression models; risks of specific-cause mortality, with Fine and Gray competing risks regression models. Time to death was counted from baseline to date of death or December 31, 2011, whichever came first. Data analysis was conducted from April 1 through 30, 2018.

Exposures

Age-related macular degeneration status as determined by digital fundus images.

Main Outcomes and Measures

Mortality resulting from all causes and specific causes until December 31, 2011.

Results

Among the 5603 participants (52.6% female [n = 2793] and 77.1% white [n = 3017]; mean [SE] age, 56.4 [0.4] years), weighted prevalence of any AMD was 6.6%, with 386 (5.8%) having early AMD and 55 (0.8%) having late AMD. After a median follow-up of 4.5 years (interquartile range, 3.6-5.6 years), 433 (5.3%) died of all causes, of whom 361 (83.1%) had no AMD, 54 (11.5%) had signs of early AMD, 18 (5.4%) had signs of late AMD, and 72 (16.9%) had any AMD at baseline. Overall, unadjusted all-cause and specific-cause mortality rates were higher for those participants who had early, late, or any AMD compared with no AMD. However, after adjusting confounding factors, only late AMD was associated with more than a doubling of all-cause mortality (hazard ratio [HR], 2.01; 95% CI, 1.00-4.03) and more than a 3-fold higher risk of mortality due to causes other than cardiovascular disease and cancer (HR, 3.42; 95% CI, 1.38-8.49). No association was identified between AMD presence or early AMD and all-cause or specific-cause mortality.

Conclusions and Relevance

In this study’s findings, only late AMD was independently associated with all-cause mortality and mortality due to causes other than cardiovascular disease and cancer, indicating that late AMD may be a marker of biological aging. Alternatively, this association may be due to unmeasured or inadequately assessed confounding factors for late AMD.

Association of Visual Impairment and All-Cause 10-Year Mortality Among Indigenous Australian Individuals Within Central Australia: The Central Australian Ocular Health Study

Importance

It is well established from different population-based studies that visual impairment is associated with increased mortality rate. However, to our knowledge, the association of visual impairment with increased mortality rate has not been reported among indigenous Australian individuals.

Objective

To assess the association between visual impairment and 10-year mortality risk among the remote indigenous Australian population.

Design, Setting, and Participants

Prospective cohort study recruiting indigenous Australian individuals from 30 remote communities located within the central Australian statistical local area over a 36-month period between July 2005 and June 2008. The data were analyzed in January 2017.

Exposures

Visual acuity, slitlamp biomicroscopy, and fundus examination were performed on all patients at recruitment. Visual impairment was defined as a visual acuity of less than 6/12 in the better eye.

Main Outcomes and Measures

Mortality rate and mortality cause were obtained at 10 years, and statistical analyses were performed. Hazard ratios for 10-year mortality with 95% confidence intervals are presented.

Results

One thousand three hundred forty-seven patients were recruited from a total target population number of 2014. The mean (SD) age was 56 (11) years, and 62% were women. The total all-cause mortality was found to be 29.3% at 10 years. This varied from 21.1% among those without visual impairment to 48.5% among those with visual impairment. After adjustment for age, sex, and the presence of diabetes and hypertension, those with visual impairment were 40% more likely to die (hazard ratio, 1.40; 95% CI, 1.16-1.70; P = .001) during the 10-year follow-up period compared with those with normal vision.

Conclusions and Relevance

Bilateral visual impairment among remote indigenous Australian individuals was associated with 40% higher 10-year mortality risk compared with those who were not visually impaired. Resource allocation toward improving visual acuity may therefore aid in closing the gap in mortality outcomes between indigenous and nonindigenous Australian individuals.

Mortality during 6 years of follow-up in relation to visual impairment and eye disease: results from a population-based cohort study of people aged 50 years and above in Nakuru, Kenya

OBJECTIVE

To estimate the association between (1) visual impairment (VI) and (2) eye disease and 6-year mortality risk within a cohort of elderly Kenyan people.

DESIGN, SETTING AND PARTICIPANTS

The baseline of the Nakuru Posterior Segment Eye Disease Study was formed from a population-based survey of 4318 participants aged ≥50 years, enrolled in 2007-2008. Ophthalmic and anthropometric examinations were undertaken on all participants at baseline, and a questionnaire was administered, including medical and ophthalmic history. Participants were retraced in 2013-2014 for a second examination. Vital status was recorded for all participants through information from community members. Cumulative incidence of mortality, and its relationship with baseline VI and types of eye disease was estimated. Inverse probability weighting was used to adjust for non-participation.

PRIMARY OUTCOME MEASURES

Cumulative incidence of mortality in relation to VI level at baseline.

RESULTS

Of the baseline sample, 2170 (50%) were re-examined at follow-up and 407 (10%) were known to have died (adjusted risk of 11.9% over 6 years). Compared to those with normal vision (visual acuity (VA) ≥6/12, risk=9.7%), the 6-year mortality risk was higher among people with VI (<6/18 to ≥6/60; risk=28.3%; risk ratio (RR) 1.75, 95% CI 1.28 to 2.40) or severe VI (SVI)/blindness (<6/60; risk=34.9%; RR 1.98, 95% CI 1.04 to 3.80). These associations remained after adjustment for non-communicable disease (NCD) risk factors (mortality: RR 1.56, 95% CI 1.14 to 2.15; SVI/blind: RR 1.46, 95% CI 0.80 to 2.68). Mortality risk was also associated with presence of diabetic retinopathy at baseline (RR 3.18, 95% CI 1.98 to 5.09), cataract (RR 1.26, 95% CI 0.95 to 1.66) and presence of both cataract and VI (RR 1.57, 95% CI 1.24 to 1.98). Mortality risk was higher among people with age-related macular degeneration at baseline (with or without VI), compared with those without (RR 1.42, 95% CI 0.91 to 2.22 and RR 1.34, 95% CI 0.99 to 1.81, respectively).

CONCLUSIONS

Visual acuity was related to 6-year mortality risk in this cohort of elderly Kenyan people, potentially because both VI and mortality are related to ageing and risk factors for NCD.

Cognitive Performance Concomitant With Vision Acuity Predicts 13-Year Risk for Mortality

Objective: To assess the joint impact of cognitive performance and visual acuity on mortality over 13-year follow-up in a representative US sample.

Methods: Data from National Health and Nutrition Examination Survey (NHANES) participants (≥18 years old) were linked with the death record data of the National Death Index (NDI) with mortality follow-up through December 31, 2011. Cognitive performance was evaluated by the Digit Symbol Substitution Test (DSST) and cognitive performance impairment was defined as the DSST score equal to or less than the median value in the study population. Visual impairment (VI) was defined as presenting visual acuity worse than 20/40 in the better-seeing eye. Risks of all-cause and specific-cause mortality were estimated with Cox proportional hazards models after adjusting for confounders.

Results: A total of 2,550 participants 60 years and older from two waves of (NHANES, 1999–2000, 2001–2002) were included in the current analysis. Over a median follow-up period of 9.92 years, 952 (35.2%) died of all causes, of whom 239 (23.1%), 224 (24.0%), and 489 (52.9%) died from cardiovascular disease (CVD), cancer, and non-CVD/non-cancer mortality, respectively. Cognitive performance impairment and VI increased the odds for mortality. Co-presence of VI among cognitive impaired elderly persons predicted nearly a threefold increased risk of all-cause mortality [hazard ratios (HRs), 2.74; 95% confidence interval (CI), 2.02–3.70; P < 0.001) and almost a fourfold higher risk of non-CVD/non-cancer mortality (HR, 3.72; 95% CI, 2.30–6.00; P < 0.001) compared to having neither impairment.

Conclusion: People aged 60 years and over with poorer cognitive performance were at higher risk of long-term mortality, and were especially vulnerable to further mortality when concomitant with VI. It is informative for clinical implication in terms of early preventive interventions.

Long-term survival rates of patients undergoing vitrectomy for diabetic retinopathy in an Australian population: a population-based audit

IMPORTANCE

Five-year survival rates in patients undergoing vitrectomy for diabetic retinopathy (DR) vary from 68% to 95%. No study has been conducted in an Australian population.

BACKGROUND

We aimed to determine the survival rates of patients undergoing diabetic vitrectomy in an Australian population.

DESIGN

Retrospective audit, tertiary centre hospitals and private practices.

PARTICIPANTS

All individuals in South Australia and the Northern Territory who underwent their first vitrectomy for diabetic complications between January 1, 2007 and December 31, 2011.

METHODS

An audit of all eligible participants has been completed previously. Survival status as of July 6, 2018 and cause of death were obtained using SA/NT DataLink. Kaplan-Meier survival curves and multivariate cox-regressions were used to analyse survival rates and identify risk factors for mortality.

MAIN OUTCOME MEASURES

Five-, seven- and nine-year survival rates.

RESULTS

The 5-, 7- and 9-year survival rates were 84.4%, 77.9% and 74.7%, respectively. The most common cause of death was cardiovascular disease. Associated with increased mortality independent of age were Indigenous ethnicity (HR = 2.04, 95% confidence interval [CI]: 1.17-3.57, P = 0.012), chronic renal failure (HR = 1.76, 95% CI: 1.07-2.89, P = 0.026) and renal failure requiring dialysis (HR = 2.32, 95% CI: 1.25-4.32, P = 0.008).

CONCLUSIONS AND RELEVANCE

Long-term survival rates after diabetic vitrectomy in Australia are similar to rates reported in other populations. Indigenous ethnicity and chronic renal failure were the most significant factors associated with long-term mortality. This information can guide allocation of future resources to improve the prognosis of these high risk groups.

Glaucoma-associated long-term mortality in a rural cohort from India: the Andhra Pradesh Eye Disease Study

Aim

To evaluate glaucoma-associated mortality in a rural cohort in India.

Methods

The study cohort comprised individuals aged 40 years and above who took part in the Andhra Pradesh Eye Disease Study (APEDS1) during 1996–2000. All participants underwent detailed comprehensive eye examination. Glaucoma was defined using International Society of Geographic and Epidemiologic Ophthalmology criteria. This cohort was followed up after a decade (June 2009 to January 2010; APEDS2). Mortality HR analysis for ocular risk factors was performed using Cox proportional hazards regression after adjusting for sociodemographic, lifestyle and clinical variables.

Results

In APEDS1, 2790 individuals aged more than or equal to 40 years were examined. 47.4% were male. Forty-five participants had primary open angle glaucoma (POAG) and 66 had primary angle closure disease (PACD). Ten years later, 1879 (67.3%) were available, 739 (26.5%) had died and 172 (6.2%) had migrated; whereas 22 of the 45 (48.8%) with POAG and 22 of the 66 (33.3%) with PACD had died. In univariate analysis, a higher mortality was associated with POAG (HR 1.9; 95% CI 1.23 to 2.94), pseudoexfoliation (HR 2.79; 95% CI 2.0 to 3.89), myopia (HR 1.78; 95% CI 1.54 to 2.06) and unit increase in cup:disc ratio (HR 4.49; 95% CI 2.64 to 7.64). In multivariable analysis, only cup:disc ratio remained independently associated with mortality (HR 2.5; 95% CI 1.3 to 5.1). The association remained significant when other ocular parameters were included in the model (HR 2.1; 95% CI 1.03 to 4.2).

Conclusions

This is the first longitudinal study to assess the association of glaucoma and mortality in a rural longitudinal cohort in India. Increased cup:disc ratio could be a potential marker for ageing and would need further validation.

International Vision Care: Issues and Approaches

Globally, 32.4 million individuals are blind and 191 million have moderate or severe visual impairment (MSVI); 80% of cases of blindness and MSVI are avoidable. However, great efforts are needed to tackle blindness and MSVI, as eye care in most places is delivered in isolation from and without significant integration with general health sectors. Success stories, including control of vitamin A deficiency, onchocerciasis, and trachoma, showed that global partnerships, multisectoral collaboration, public-private partnerships, corporate philanthropy, support from nongovernmental organizations-both local and international-and governments are responsible for the success of these programs. Hence, the World Health Organization's universal eye health global action plan for 2014-2019 has a goal of reducing the public health problem of blindness and ensuring access to comprehensive eye care; the plan aims to integrate eye health into health systems, thus providing universal eye health coverage (UEHC). This article discusses the challenges faced by low- and middle-income countries in strengthening the six building blocks of the health system. It discusses how the health systems in these countries need to be geared toward tackling the issues of emerging noncommunicable eye diseases, existing infectious diseases, and the common causes of blindness and visual impairment, such as cataract and refractive error. It also discusses how some of the comprehensive eye care models in the developing world have addressed these challenges. Moving ahead, if we are to achieve UEHC, we need to develop robust, sustainable, good-quality, comprehensive eye care programs throughout the world, focusing on the areas of greatest need. We also need to develop public health approaches for more complex problems such as diabetic retinopathy, glaucoma, childhood blindness, corneal blindness, and low vision. There is also a great need to train high-level human resources of all cadres in adequate numbers and quality. In addition to this, we need to exploit the benefits of modern technological innovations in information, communications, biomedical technology, and other domains to enhance quality of, access to, and equity in eye care.

miR-24-p53 pathway evoked by oxidative stress promotes lens epithelial cell apoptosis in age-related cataracts

MicroRNA-24 (miR-24) serves an important role in cell proliferation, migration and inflammation in various types of disease. In the present study, the biological function and molecular mechanism of miR-24 was investigated in association with the progression of age-associated cataracts. To the best of our knowledge the present study is the first to report that the expression of miR-24 was significantly increased in human anterior lens capsules affected by age-associated cataracts as well as lens epithelial cells (LECs) exposed to oxidative stress. Overexpression of miR-24 induced p53 expression and p53 was verified as a direct target of miR-24. Overexpression of miR-24 enhanced LEC death by directly targeting p53. The present study revealed that oxidative stress induced the upregulation of miR-24 and enhanced LEC death by directly targeting p53. These results suggest that the miR-24-p53 signaling pathway is involved in a novel mechanism of age-associated cataractogenesis and miR-24 may be a useful therapeutic target for age-associated cataracts.

AGE-RELATED MACULAR DEGENERATION AND THE RISK OF ALL-CAUSE AND CARDIOVASCULAR MORTALITY: A Meta-Analysis of Cohort Studies

PURPOSE

We evaluated the association between age-related macular degeneration (AMD) and the risk of all-cause and cardiovascular mortality by meta-analyses of data from prospective studies.

METHODS

A literature search was performed in PubMed, Web of Science, Embase, Cocharne Library, and China National Knowledge Infrastructure for relevant articles published up to December 2016. We estimated hazard ratios with 95% confidence intervals with fixed-effect models and conducted meta-regression to explore the potential sources of heterogeneity. Small-study effect was estimated by Egger's test and funnel plot.

RESULTS

We identified 13 population-based prospective cohort studies that examined the relationship between AMD and all-cause and cardiovascular mortality. Overall, the hazard ratios (95% confidence intervals) of all-cause mortality and cardiovascular mortality associated with any AMD were 1.15 (1.05-1.27) and 1.05 (95% confidence intervals: 0.87-1.26), respectively. The risk of all-cause mortality and cardiovascular mortality associated with early AMD were 1.08 (1.00-1.18) and 1.05 (0.89-1.24), and the associations with late AMD were 1.23 (1.11-1.36) and 1.28 (1.04-1.57), respectively. No evidence of small-study effect was found.

CONCLUSION

This meta-analysis indicated that AMD, especially late AMD, was associated with increased risk of all-cause mortality and cardiovascular mortality based on comparisons with people who did not have AMD and who were of similar age and sex.

Association of disease-specific causes of visual impairment and 10-year mortality amongst Indigenous Australians: the Central Australian Ocular Health Study

IMPORTANCE

Visual impairment significantly impairs the length and quality of life, but little is known of its impact in Indigenous Australians.

BACKGROUND

To investigate the association of disease-specific causes of visual impairment with all-cause mortality.

DESIGN

A retrospective cohort analysis.

PARTICIPANTS

A total of 1347 Indigenous Australians aged over 40 years.

METHODS

Participants visiting remote medical clinics underwent clinical examinations including visual acuity, subjective refraction and slit-lamp examination of the anterior and posterior segments. The major ocular cause of visual impairment was determined. Patients were assessed periodically in these remote clinics for the succeeding 10 years after recruitment. Mortality rates were obtained from relevant departments.

MAIN OUTCOME MEASURES

All-cause 10-year mortality and its association with disease-specific causes of visual impairment.

RESULTS

The all-cause mortality rate for the entire cohort was 29.3% at the 10-year completion of follow-up. Of those with visual impairment, the overall mortality rate was 44.9%. The mortality rates differed for those with visual impairment due to cataract (59.8%), diabetic retinopathy (48.4%), trachoma (46.6%), 'other' (36.2%) and refractive error (33.4%) (P < 0.0001). Only those with visual impairment from diabetic retinopathy were any more likely to die during the 10 years of follow-up when compared with those without visual impairment (HR 1.70; 95% CI, 1.00-2.87; P = 0.049).

CONCLUSIONS AND RELEVANCE

Visual impairment was associated with all-cause mortality in a cohort of Indigenous Australians. However, diabetic retinopathy was the only ocular disease that significantly increased the risk of mortality. Visual impairment secondary to diabetic retinopathy may be an important predictor of mortality.

Six-Year Incidence of Blindness and Visual Impairment in Kenya: The Nakuru Eye Disease Cohort Study

Purpose

To describe the cumulative 6-year incidence of visual impairment (VI) and blindness in an adult Kenyan population. The Nakuru Posterior Segment Eye Disease Study is a population-based sample of 4414 participants aged ≥50 years, enrolled in 2007–2008. Of these, 2170 (50%) were reexamined in 2013–2014.

Methods

The World Health Organization (WHO) and US definitions were used to calculate presenting visual acuity classifications based on logMAR visual acuity tests at baseline and follow-up. Detailed ophthalmic and anthropometric examinations as well as a questionnaire, which included past medical and ophthalmic history, were used to assess risk factors for study participation and vision loss. Cumulative incidence of VI and blindness, and factors associated with these outcomes, were estimated. Inverse probability weighting was used to adjust for nonparticipation.

Results

Visual acuity measurements were available for 2164 (99.7%) participants. Using WHO definitions, the 6-year cumulative incidence of VI was 11.9% (95%CI [confidence interval]: 10.3–13.8%) and blindness was 1.51% (95%CI: 1.0–2.2%); using the US classification, the cumulative incidence of blindness was 2.70% (95%CI: 1.8–3.2%). Incidence of VI increased strongly with older age, and independently with being diabetic. There are an estimated 21 new cases of VI per year in people aged ≥50 years per 1000 people, of whom 3 are blind. Therefore in Kenya we estimate that there are 92,000 new cases of VI in people aged ≥50 years per year, of whom 11,600 are blind, out of a total population of approximately 4.3 million people aged 50 and above.

Conclusions

The incidence of VI and blindness in this older Kenyan population was considerably higher than in comparable studies worldwide. A continued effort to strengthen the eye health system is necessary to support the growing unmet need in an aging and growing population.

The Association between Age-Related Macular Degeneration and the Risk of Mortality

Studies have investigated the association between age-related macular degeneration (AMD) and subsequent risks of mortality, but results have been equivocal. We conducted a comprehensive analysis of prospective cohort studies to assess the association of AMD and the risk of mortality in the general population. We searched PubMed and EMBASE for trials published from 1980 to 2016. We included 11 cohort studies that reported relative risks with 95% confidence intervals for the association of AMD and mortality, involving 57,069 participants. In a random-effects model, the adjusted RR (95% confidence interval) associated with AMD was 1.09 (1.02-1.17) for all-cause mortality. Findings from this research provide support that persons with AMD had a higher subsequent risk of mortality than persons without AMD.

The impact of age-related cataract on measures of frailty in an aging global population

PURPOSE OF REVIEW

To review the associations among age-related cataract, frailty, and frailty outcomes (e.g., disabilities).

RECENT FINDINGS

It is predicted that the proportion of the population aged 65 and older, in developed and developing nations alike, will rise until at least 2050. The proportion of patients suffering from cataracts and frailty is expected to increase, as are age-related diseases. Although there are many papers reporting on the association between frailty outcomes, cataract, and visual impairment, there is a relative paucity of papers describing associations between frailty markers, cataract, and visual impairment.

SUMMARY

Reports regarding the relationship between frailty, visual impairment, cataract, and cataract surgery are limited, but gradually increasing. Further research is expected to clarify the mechanism of visual function or the impact of restored vision on frailty. Evidence for the effect of cataract on frailty and frailty outcomes after restoring vision by cataract surgery remains limited.

Population-based assessment of prevalence and causes of visual impairment in the state of Telangana, India: a cross-sectional study using the Rapid Assessment of Visual Impairment (RAVI) methodology

OBJECTIVE

To assess the prevalence and causes of visual impairment (VI) among a rural population aged 40 years and older in the state of Telangana in India.

DESIGN

Population-based cross-sectional study.

SETTING

Districts of Adilabad and Mahbubnagar in south Indian state of Telangana, India.

PARTICIPANTS

A sample of 6150 people was selected using cluster random sampling methodology. A team comprising a trained vision technician and a field worker visited the households and conducted the eye examination. Presenting, pinhole and aided visual acuity were assessed. Anterior segment was examined using a torchlight. Lens was examined using distant direct ophthalmoscopy in a semidark room. In all, 5881 (95.6%) participants were examined from 123 study clusters. Among those examined, 2723 (46.3%) were men, 4824 (82%) had no education, 2974 (50.6%) were from Adilabad district and 1694 (28.8%) of them were using spectacles at the time of eye examination.

PRIMARY OUTCOME MEASURE

VI was defined as presenting visual acuity <6/18 in the better eye and it included moderate VI (<6/18 to 6/60) and blindness (<6/60).

RESULTS

The age-adjusted and gender-adjusted prevalence of VI was 15.0% (95% CI 14.1% to 15.9%). On applying binary logistic regression analysis, VI was associated with older age groups. The odds of having VI were higher among women (OR 1.2; 95% CI 1.0 to 1.4). Having any education (OR 0.4; 95% CI 0.3 to 0.6) and current use of glasses (OR 0.19; 95% CI 0.1 to 0.2) were protective. VI was also higher in Mahbubnagar (OR 1.0 to 1.5) district. Cataract (54.7%) was the leading cause of VI followed by uncorrected refractive errors (38.6%).

CONCLUSIONS

VI continues to remain a challenge in rural Telangana. As over 90% of the VI is avoidable, massive eye care programmes are required to address the burden of VI in Telangana.

Unilateral visual impairment in rural south India-Andhra Pradesh Eye Disease Study (APEDS)

AIM

To report the prevalence and causes of unilateral visual impairment (UVI) in rural population of all ages in rural Andhra Pradesh, India.

METHODS

A population-based cross sectional study using a multi-stage cluster sampling methodology was carried out in West Godavari, Adilabad and Mahbubnagar districts in south India. A comprehensive eye examination that included presenting and best corrected visual acuity and dilated fundus examination was conducted by trained professionals. UVI is defined as presenting visual acuity <6/18 in one eye but ≥6/18 in other eye. Multiple logistic regression analysis was used to test association of UVI with socio-demographic risk factors.

RESULTS

Data were analyzed for 6634/7771 participants after excluding those with bilateral visual impairment. The mean age of the participants was 27.4y (standard deviation: 17.9y), 51.9% were women and 49.1% were educated. The prevalence of UVI was 7.8% (95% CI: 7.2%-8.5%). Uncorrected refractive error (60.8%), cataract (17.4%) and retinal causes (6.6%) were the leading causes of UVI. On multiple logistic regression analyses, older age, not having education, living in well-off district had significantly higher odds of being associated with UVI. UVI was not associated with gender.

CONCLUSION

UVI is common in rural south India. Most of it is due to cataract and refractive errors, both of which can be addressed at primary and secondary levels of eye care. Burden of UVI should also be considered in planning eye care services.

Cataract Surgery and Mortality in the United States Medicare Population

PURPOSE

To determine the association between cataract surgery and all-cause mortality in United States Medicare patients with cataract.

DESIGN

Retrospective cohort study.

PARTICIPANTS

A 5% random sample of United States Medicare beneficiaries with a diagnosis of cataract from the 2002 through 2012 Denominator and Physician/Supplier Part B files.

METHODS

The exposure of interest was cataract surgery and the outcome of interest was all-cause mortality. Baseline characteristics that were examined included demographics, systemic comorbidities, and ocular comorbidities. Cox proportional hazards regression modeling was used to assess the association between cataract surgery and mortality. Additional subgroup analyses were performed in propensity score deciles and within strata of age, gender, region, systemic disease burden, and in patients with versus without severe cataract subtypes.

MAIN OUTCOME MEASURES

All-cause mortality.

RESULTS

The 5% Medicare sample included 1 501 420 patients with cataract, of whom 544 984 (36.3%) underwent cataract surgery. Patients with cataract surgery were followed up for a mean of 11.4 quarters (standard deviation [SD], 10.8 quarters; range, 0.0-44.0 quarters), whereas patients without cataract surgery were followed up for a mean of 12.9 quarters (SD, 12.2 quarters; range, 0.0-44.0 quarters). Mortality incidence was 2.78 deaths per 100 person-years in patients with cataract surgery and 2.98 deaths per 100 person-years in patients without surgery (P < 0.0001). Overall, patients with cataract surgery had a lower adjusted hazard of mortality compared with patients without surgery (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.72-0.74). The strongest associations were observed in patients with a high propensity score decile (HR, 0.52; 95% CI, 0.50-0.54), patients 80 to 84 years of age (HR, 0.63; 95% CI, 0.62-0.65), women (HR, 0.69; 95% CI, 0.68-0.70), patients in the western United States (HR, 0.52; 95% CI, 0.32-0.86), patients with a moderate systemic disease burden (HR, 0.71; 95% CI, 0.69-0.72), and patients with severe cataract (HR, 0.68; 95% CI, 0.66-0.70).

CONCLUSIONS

In a national cohort of United States Medicare beneficiaries with cataract, cataract surgery was associated with decreased all-cause mortality. Further studies are needed to examine mechanisms surrounding the association between cataract surgery and mortality.

Impact of Visual Impairment and Eye diseases on Mortality: the Singapore Malay Eye Study (SiMES)

We investigated the relationship of visual impairment (VI) and age-related eye diseases with mortality in a prospective, population-based cohort study of 3,280 Malay adults aged 40–80 years between 2004–2006. Participants underwent a full ophthalmic examination and standardized lens and fundus photographic grading. Visual acuity was measured using logMAR chart. VI was defined as presenting (PVA) and best-corrected (BCVA) visual acuity worse than 0.30 logMAR in the better-seeing eye. Participants were linked with mortality records until 2012. During follow-up (median 7.24 years), 398 (12.2%) persons died. In Cox proportional-hazards models adjusting for relevant factors, participants with VI (PVA) had higher all-cause mortality (hazard ratio[HR], 1.57; 95% confidence interval[CI], 1.25–1.96) and cardiovascular (CVD) mortality (HR 1.75; 95% CI, 1.24–2.49) than participants without. Diabetic retinopathy (DR) was associated with increased all-cause (HR 1.70; 95% CI, 1.25–2.36) and CVD mortality (HR 1.57; 95% CI, 1.05–2.43). Retinal vein occlusion (RVO) was associated with increased CVD mortality (HR 3.14; 95% CI, 1.26–7.73). No significant associations were observed between cataract, glaucoma and age-related macular degeneration with mortality. We conclude that persons with VI were more likely to die than persons without. DR and RVO are markers of CVD mortality.

Age-related cataract, cataract surgery and subsequent mortality: a systematic review and meta-analysis

PURPOSE

Changes in lens may reflect the status of systemic health of human beings but the supporting evidences are not well summarized yet. We aimed to determine the relationship of age-related cataract, cataract surgery and long-term mortality by pooling the results of published population-based studies.

METHODS

We searched PubMed and Embase from their inception till March, 2014 for population-based studies reporting the associations of any subtypes of age-related cataract, cataract surgery with all-cause mortality. We pooled the effect estimates (hazards ratios [HRs]) under a random effects model.

RESULTS

Totally, we identified 10 unique population-based studies including 39,659 individuals at baseline reporting the associations of any subtypes of cataract with all-cause mortality from 6 countries. The presence of any cataract including cataract surgery was significantly associated with a higher risk of death (pooled HR: 1.43, 95% CI, 1.21, 2.02; P<0.001; I(2) = 64.2%). In the meta-analysis of 9 study findings, adults with nuclear cataract were at higher risks of mortality (pooled HR: 1.55, 95% CI, 1.17, 2.05; P = 0.002; I(2) = 89.2%). In the meta-analysis of 8 study findings, cortical cataract was associated with higher risks of mortality (pooled HR: 1.26, 95% CI, 1.12, 1.42; P<0.001, I(2) = 29.7%). In the meta-analysis of 6 study findings, PSC cataract was associated with higher risks of mortality (pooled HR: 1.37, 95% CI, 1.04, 1.80; P = 0.03; I(2) = 67.3%). The association between cataract surgery and mortality was marginally non-significant by pooling 8 study findings (pooled HR: 1.27, 95% CI, 0.97, 1.66; P = 0.08; I(2)= 76.6%).

CONCLUSIONS

All subtypes of age-related cataract were associated with an increased mortality with nuclear cataract having the strongest association among the 3 cataract subtypes. However, cataract surgery was not significantly related to mortality. These findings indicated that changes in lens may serve as markers for ageing and systemic health in general population.

Value of interactive scanning for improving the outcome of new-learners in transcontinental tele-echocardiography (VISION-in-Tele-Echo) study

BACKGROUND

Point-of-care (POC) echocardiography may be helpful for mass triage, but such a strategy requires adequately trained sonographers at the remote site. The aim of this study was to test the feasibility of using a novel POC echocardiography training program for improving physicians' imaging skills during preanesthetic cardiac evaluations performed in a community camp organized for treating cataract blindness.

METHODS

Seventeen physicians were provided 6 hours of training in the use of POC echocardiography; nine were taught on site and eight were taught online through a transcontinental tele-echocardiography system. The trained physicians subsequently scanned elderly patients undergoing cataract surgery. The quality of images was graded, and agreement between local physicians' interpretations and Web-based interpretations by worldwide experts was compared.

RESULTS

A total of 968 studies were performed, with 660 used for validating physicians' competence. Major cardiac abnormalities were seen in 136 patients (14.2%), with 32 (3.3%) deemed prohibitive to surgery in unmonitored settings. Although good-quality images were obtained more frequently by physicians trained on site rather than online (P = .03), there were no differences between the two groups in agreement with expert interpretations. The majority of physicians (70.6%) expressed satisfaction with the training (average Likert-type scale score, 4.24 of 5), with no difference seen between the two groups. The training resulted in significant improvements in self-perceived competence in all components of POC echocardiography (P < .001 for all).

CONCLUSIONS

This study establishes the feasibility of using short-duration, one-on-one, personalized transcontinental tele-echocardiography education for wider dissemination of echocardiographic skills to local physicians in remote communities, essential for optimizing global cardiovascular health.