Comparing a Head-Mounted Smartphone Visual Field Analyzer to Standard Automated Perimetry in Glaucoma: A Prospective Study.

PRECIS: Wang et al compare an FDA-registered head-mounted smartphone device (PalmScan VF2000) with standard automated perimetry (SAP) in glaucoma patients and find that the head-mounted device may not fully recapitulate SAP testing. PURPOSE: This study prospectively compared visual field testing using the PalmScan VF2000 Visual Field Analyzer, a head-mounted smartphone device, with standard automated perimetry (SAP). METHODS: Patients with glaucoma undergoing Humphrey Field Analyzer SAP testing were asked to complete in-office PalmScan testing using a Samsung S5 smartphone in a virtual reality-style headset. Glaucoma severity was defined as SAP mean deviation (MD) >-6 dB for mild, between -6 and -12 dB for moderate, and <-12 dB for severe. Global parameters MD and pattern standard deviation (PSD) from PalmScan and SAP were compared using t-tests and Bland-Altman analyses. Bland-Altmann analyses of PalmScan and SAP MD were conducted for the superonasal, superotemporal, inferonasal, and inferotemporal visual field quadrants. The repeatability of PalmScan was assessed using Spearman's correlations and intraclass correlation coefficients (ICCs). RESULTS: Fifty-one patients (51 eyes) completed both SAP and PalmScan testing and met criteria for analysis. Compared to SAP, global MD and PSD measurements from PalmScan differed by an average of +0.62±0.26 dB (range: -3.25 to +4.60 dB) and -1.00±0.24 dB (range: -6.03 to +2.77 dB), respectively, while MD scores from individual visual field quadrants differed by as much as -6.58 to +11.43 dB. Agreement of PalmScan and SAP in classifying glaucoma severity was 86.3% across all eyes. PalmScan and SAP identified the same quadrant as having the worst visual field defect in 66.7% of eyes. CONCLUSIONS: Despite advantages in cost and accessibility, the PalmScan head-mounted perimetry device may not be able to fully recapitulate SAP testing.

Comparison of Photographic Screening Methods for Diabetic Retinopathy - A Meta-analysis.

INTRODUCTION: Diabetic Retinopathy (DR) is a leading cause of irreversible visual impairment and blindness in both developed and developing countries. Although the merits of DR screening are well recognized, significant variations in screening practices including imaging modality still exists. PURPOSE: To evaluate and compare the sensitivity and specificity of mydriatic and non-mydriatic photographic screening methods using 7-Field fundus photography or dilated fundus examination (DFE) by an ophthalmologist as reference standard. METHODS: A systematic review using PRISMA Guidelines was conducted by online search of MEDLINE, Web of Science, and other repositories of all available studies from 1990 until 2019. A total of 62 studies were included in the meta-analysis from a total of 406 suitable abstracts screened and 95 articles reviewed in full. Data were collected using a standardized extraction form independently, with all authors masked to others' search results. RESULTS: For the detection of any DR (ADR), sensitivity ranged from 81% with single field to a maximum of 99% for 4-7 fields and wide-angle images. For detection of referable DR (RDR) sensitivity ranged from 76% for single field to 93% for wide-angle photography. Specificity was lowest at 91% for wide-angle images and greatest at 99% for three field photography. Study heterogeneity was noted to be significant, which was partly attributed to the range of DR classification between studies. CONCLUSIONS: The sensitivity and specificity of DR screening are positively associated with number of photographic fields. Pooled estimates suggest non-mydriatic two-field photography may be sufficient for screening detection of ADR and RDR.

High-fat diet-induced hyperinsulinemia promotes the development of prostate adenocarcinoma in prostate-specific Pten-/- mice.

Metabolic syndrome (MetS) and its four clinical entities, central obesity, insulin resistance, hypertension and dyslipidemia, are implicated in increasing the risk and mortality of cancer in several organs. However, it is unclear how they are associated with increased risk of prostate cancer. To elucidate the mechanistic link between MetS and prostate carcinogenesis, we characterized the development of MetS and prostate adenocarcinoma in prostate-specific Pten-/- (Ptenp-/-) mice fed a high-fat (HF) diet. We found that male Ptenp-/- mice on an HF diet gained excess body weight and elevated blood glucose, insulin and insulin-like growth factor 1 (IGF1) levels at 20 weeks of age and were obese at 40 weeks. Prostate adenocarcinoma multiplicity at 40 weeks was significantly higher in the mice on an HF diet, suggesting that the HF diet promotes the development of prostate adenocarcinoma. Increased cell proliferation and enhanced AKT activation were found in the prostates of mice on an HF diet. Further transcriptome study revealed that receptor tyrosine kinase regulation, which mediates insulin/IGF1 signaling, was one of the top enriched pathways by HF diet-induced transcriptome changes. Together, our results suggest that HF diet-induced hyperinsulinemia leads to increased activation of insulin/IGF1/AKT signaling in lesioned prostates, promoting the development of adenocarcinoma.

δ-Tocotrienol is the Most Potent Vitamin E Form in Inhibiting Prostate Cancer Cell Growth and Inhibits Prostate Carcinogenesis in Ptenp-/- Mice.

Vitamin E compounds, consisting of α, ß, γ, and δ forms of tocopherols and tocotrienols, display different cancer preventive activities in experimental models. Tocotrienols may have higher potential for clinical use due to their lower effective doses in laboratory studies. However, most studies on tocotrienols have been carried out using cancer cell lines. Strong data from animal studies may encourage the use of tocotrienols for human cancer prevention research. To examine the cancer inhibitory activity of different vitamin E forms, we first investigated their inhibitory activities of different vitamin E forms in prostate cancer cell lines. We found that δ-tocotrienol (δT3) was the most effective form in inhibiting cell growth at equivalent doses. Because of this in vitro potency, δT3 was further studied using prostate-specific Pten-/- (Ptenp-/-) mice. We found that 0.05% δT3 in diet reduced prostate adenocarcinoma multiplicity by 32.7%, featuring increased apoptosis and reduced cell proliferation. The inhibitory effect of 0.05% δT3 in diet was similar to that of 0.2% δ-tocopherol (δT) in diet reported previously. Our further study on the δT3-induced transcriptome changes indicated that δT3 inhibited genes in blood vessel development in the prostate of Ptenp-/- mice, which was confirmed by IHC. Together, our results demonstrate that δT3 effectively inhibits the development of prostate adenocarcinoma in Ptenp-/- mice, which involves inhibition of proliferation and angiogenesis and promotion of apoptosis. PREVENTION RELEVANCE: We demonstrated that δ-tocotrienol is the most active vitamin E form in inhibiting the growth of several prostate cancer cell lines. In transgenic Ptenp-/- mice, δ-tocotrienol inhibited the formation of prostate cancer. This result would encourage and help design clinical studies for the application of δ-tocotrienol for prostate cancer prevention.

Association of refraction and ocular biometry in highly myopic eyes.

Clinical relevance: Ocular biometry is key to understanding the determinants of ocular development and pathology changes, especially for the thriving myopic population in Asia. Investigating biometric data in highly myopic eyes within a wide age spectrum is therefore of high importance.Background: To report the magnitude of change in spherical equivalent for each unit of change in the ocular biometry parameters in a highly myopic population in China.Methods: Highly myopic patients aged 7 to 70 years were recruited from the Zhongshan Ophthalmic Center, China. Each patient had a cycloplegic refraction and a measurement of ocular biometry.Results: Data from 823 right eyes were available for analysis, with a mean age of 22.7 years and a median spherical equivalent of -8.88 D. Axial length and lens thickness increased with age, while anterior chamber depth (ACD) decreased in older subjects. There was a significant trend of increasing axial length, lens thickness, vitreous chamber depth (VCD) and decreasing ACD and calculated lens power over spherical equivalent quartiles (all p < 0.001). The univariate linear regression models showed that 1-D change in refraction equalled to a 0.33- to 0.34-mm increase of axial length, and a 0.32 to 0.33-mm increase of VCD in highly myopic eyes. Among the three components of axial length, lens thickness was associated with myopia shift in the groups of 7-18 years and 19-39 years (both p < 0.001), and VCD was significant in all groups (all p < 0.001), while ACD was not significant in any age group.Conclusion: The associations between refraction and axial length were consistent in children, young adults and the elderly with high myopia. Lens thickening with a higher degree of myopia appeared at a very early age, and vitreous chamber depth remained to be a prominent factor of refraction change in highly myopic eyes throughout seven to 70 years of age.

Female Gender Remains a Significant Barrier to Access Cataract Surgery in South Asia: A Systematic Review and Meta-Analysis.

PURPOSE: To determine whether the female gender is a barrier for the access to cataract surgery services in South Asia in the last two decades. METHODS: Eligible cross-sectional studies were identified via computer searches and reviewing the reference lists of the obtained articles. The cataract surgical coverage (CSC) by sex based on person and eyes at visual acuity <3/60 and 6/18 is extracted. Pooled odds ratios (ORs) for males receiving cataract surgery in comparison with females were calculated by a random effect model. RESULTS: Sixteen studies with 135972 subjects were included in the final analysis. The pooled ORs of CSC by sex on a person basis at visual acuity <3/60 and at visual acuity <6/18 were 1.46 (95% CI: 1.23-1.75) and 1.14 (95% CI: 1.05-1.24), respectively. For CSC on a per-eye basis at visual acuity <3/60, the associations were statistically significant, with a pooled OR of 1.40 (95% CI: 1.16-1.70). The values of population attributable risk percentage at a per-person and per-eye basis at visual acuity <3/60 were 6.28% and 7.48%, respectively. Subgroup analyses by design and location types attained similar results as the primary analyses. There was no evidence of publication bias. CONCLUSIONS: The female gender remains a significant barrier for the access to cataract surgery in South Asia. Visual impairment, including blindness, from unoperated cataract, could be reduced by approximately 6.28% with the elimination of gender disparities to access. More efforts are needed to increase eye care service utilization by female population.

Regulatory landscape of dietary supplements and herbal medicines from a global perspective.

The number of Individuals that use dietary supplements and herbal medicine products are continuous to increase in many countries. The context of usage of a dietary supplement varies widely from country-to-country; in some countries supplement use is just limited to general health and well-being while others permit use for medicinal purposes. To date, there is little consensus from country to country on the scope, requirements, definition, or even the terminology in which dietary supplement and herbal medicines categories could be classified. Transparent science-based quality standards for the ingredients across these regulatory frameworks/definitions becomes even more important given the international supply chain. Meanwhile, there has been a rapid advancement in emerging technologies and data science applied to the field. This review was conceived at the Global Summit on Regulatory Sciences that took place in Beijing on September 2018 (GSRS2018) which is organized by Global Coalition for Regulatory Science Research (GCRSR) that consists of the global regulatory agencies from over ten countries including the European Union. This review summarizes a significant portion of discussions relating to a longitudinal comparison of the status for dietary supplements and herbal medicines among the different national jurisdictions and to the extent of how new tools and methodologies can improve the regulatory application.

Perspective: Guiding Principles for the Implementation of Personalized Nutrition Approaches That Benefit Health and Function.

Personalized nutrition (PN) approaches have been shown to help drive behavior change and positively influence health outcomes. This has led to an increase in the development of commercially available PN programs, which utilize various forms of individual-level information to provide services and products for consumers. The lack of a well-accepted definition of PN or an established set of guiding principles for the implementation of PN creates barriers for establishing credibility and efficacy. To address these points, the North American Branch of the International Life Sciences Institute convened a multidisciplinary panel. In this article, a definition for PN is proposed: "Personalized nutrition uses individual-specific information, founded in evidence-based science, to promote dietary behavior change that may result in measurable health benefits." In addition, 10 guiding principles for PN approaches are proposed: 1) define potential users and beneficiaries; 2) use validated diagnostic methods and measures; 3) maintain data quality and relevance; 4) derive data-driven recommendations from validated models and algorithms; 5) design PN studies around validated individual health or function needs and outcomes; 6) provide rigorous scientific evidence for an effect on health or function; 7) deliver user-friendly tools; 8) for healthy individuals, align with population-based recommendations; 9) communicate transparently about potential effects; and 10) protect individual data privacy and act responsibly. These principles are intended to establish a basis for responsible approaches to the evidence-based research and practice of PN and serve as an invitation for further public dialog. Several challenges were identified for PN to continue gaining acceptance, including defining the health-disease continuum, identification of biomarkers, changing regulatory landscapes, accessibility, and measuring success. Although PN approaches hold promise for public health in the future, further research is needed on the accuracy of dietary intake measurement, utilization and standardization of systems approaches, and application and communication of evidence.

Utilisation and perceptions towards smart device visual acuity assessment in Australia: a mixed methods approach.

OBJECTIVES: To investigate mobile health product use in Australia and societal and clinician perceptions towards smartphone based visual acuity (VA) assessment tools. DESIGN: Quantitative analysis of a cross-sectional survey delivered to the general public and thematic analysis of in-depth interviews of eye health clinicians. SETTING: Online survey within Australia and face-to-face in-depth interviews of clinicians. PARTICIPANTS: 1016 adults were recruited via Survey Monkey Audience, social media (Facebook and Twitter), Rotary Australia and Lions Clubs Australia. Six clinicians were recruited from private and public settings in Melbourne, Australia. PRIMARY AND SECONDARY OUTCOME MEASURES: The study assessed socio-demographic characteristics, history of mobile health product use and perceived advantages and potential drawbacks of smartphone based VA assessment tools. RESULTS: A total of 14.4% of the study population had previously used a mobile-based health product. After adjusting for covariates, younger age (p=0.001), male gender (p=0.01) and higher income (>$45 000) were associated with increased likelihood of having used a mobile health product (p=0.005). Seventy-two per cent of participants would use an automated smartphone based VA assessment tool, provided that the accuracy was on par to that of human assessors. Convenience (37.3%) and cost-savings (15.5%) were ranked as the greatest perceived advantages. While test accuracy (50.6%), a lack of personal contact with healthcare providers (18.3%) and data security (11.9%) were the greatest concerns. Themes to emerge from clinician qualitative data included the potential benefits for identifying refractive error in patients, as well as the ability to self-monitor vision. Concerns were raised over the potential misuse of self-testing vision apps and the inability to detect pathology. CONCLUSION: Our findings suggest that a substantial proportion of the Australian population do not use mobile health products. Furthermore, there remains notable concerns, including test accuracy and data privacy, with smartphone-based VA assessment tools by both clinicians and the public.

Ten-year changes of intraocular pressure in adults: the Liwan Eye Study.

IMPORTANCE: Understanding the longitudinal intraocular pressure (IOP) changes and potential risk factors in adults is important for future glaucoma control in the aging society. BACKGROUND: Limited longitudinal studies exist in Asia investigating the longitudinal IOP changes and with varying results. DESIGN: Population-based cohort study. PARTICIPANTS: 1405 baseline participants from the Liwan Eye Study. METHODS: All baseline participants were invited for the 10-year follow-up examination in 2013. IOP (by Tonopen), central corneal thickness (CCT; by ultrasound), refractive error (by autorefractor), blood pressure, height and weight were measured per standardized protocol and the presence of hypertension or diabetes was collected by questionnaire. Follow-up examinations were conducted using the same equipment with proper calibration. Linear regression analysis was used to assess the association between IOP change and potential risk factors. MAIN OUTCOME MEASURES: 10-year IOP change. RESULTS: Of the 791 participants at the 10-year follow-up, IOP data were available for 602 participants with a mean age of 60.9 years (55.5% female). The average IOP change over 10 years was an increase of 1.44 mmHg (95% confidence interval, 1.12-1.75). Linear regression showed that 10-year IOP change was not associated with baseline age, gender, body mass index (BMI), CCT, spherical equivalence (SE), hypertension or diabetes. However, it was positively associated with longitudinal increase of BMI when longitudinal changes of BMI and SE were included in the model (P < 0.001). CONCLUSIONS AND RELEVANCE: We observed a small increase in IOP over 10 years in this adult Chinese population, which was positively related to the longitudinal change in BMI.

Longitudinal changes in global cataract surgery rate inequality and associations with socioeconomic indices.

IMPORTANCE: Cataract is the leading cause of blindness and the second leading cause of vision impairment. The majority of people with vision impairment reside in low-resource settings with limited access to cataract surgery and services. BACKGROUND: Cataract surgery rate (CSR) is a proxy measure for eye care service delivery and estimating the burden of cataract disease. This research aims to evaluate the longitudinal changes of CSR inequality globally and by income groups. DESIGN: Systematic review. PARTICIPANTS: Studies published from January 2000 to December 2015 were considered for inclusion into the review. METHODS: CSR data were retrieved from a systematic review of published literature (OVID Medline, Embase, PubMed, ISI, Web of Science), unpublished reports and data repositories. MAIN OUTCOME MEASURES: Inequality of CSR was measured on a global scale and between countries grouped by income levels using the Gini coefficient and concentration index, with respect to the human development index (HDI). RESULTS: Overall, correlations between HDI and gross domestic product (GDP) per capita vs CSRs were observed with R2 values of 49.2% (ß = 5.01, P < 0.001) and 38.9% (ß = 0.56, P < 0.001), respectively. Analysis of longitudinal CSR data using generalized estimation equation models revealed strong associations between CSR and HDI (P < 0.001), GDP (P < 0.001) and the proportion of people aged ≥50 (P = 0.001). Overall, the trend of inequality in worldwide CSR remained relatively stable. CONCLUSIONS AND RELEVANCE: Inequalities in cataract service provision were found between countries grouped by income and associated with socioeconomic indicators.

Longitudinal changes in intraocular pressure and association with systemic factors and refractive error: Lingtou Eye Cohort Study.

OBJECTIVES: To investigate the longitudinal changes in intraocular pressure (IOP) and its associations with refractive error and systemic determinants in a Chinese geriatric population. DESIGN: Prospective cohort study. SETTING: Guangzhou Government Servant Physical Check-up Center, Guangzhou, China. PARTICIPANTS: 4413 government employees aged no less than 40 years (41.9% female) attending annual physical and eye examinations were included in this study. The inclusion criterion was having attended the 2010 follow-up examination. The exclusion criteria include glaucoma or intraocular surgery history, IOP >21 mm Hg at any visit or without available IOP data at all visits from 2010 to 2014. PRIMARY AND SECONDARY OUTCOME MEASURES: The outcome measure was IOP at each follow-up visit from 2010 to 2014. Mixed-effect model was used to assess the relationship between longitudinal changes in IOP and potential risk factors. RESULTS: For the 2653 participants who had available IOP data at both the 2010 and 2014 follow-up visits, the average change in IOP was an increase of 0.43 (95% CI 0.36 to 0.50) mm Hg. For the whole study population and in the optimised mixed model, there was a non-linear increase of IOP with age (P<0.001), with greater changes in younger subjects and in women (P<0.001 and P=0.002, respectively). Elevations in systolic blood pressure, diastolic blood pressure, body mass index (BMI) and fasting plasma glucose (FPG), as well as a myopic shift (all with P<0.001), during the follow-up were associated with an increasing trend of IOP, while serum lipids were found to be not significantly associated. CONCLUSIONS: In this cohort of elderly Chinese adults, IOP increases non-linearly with ageing. People with increasing blood pressure, BMI, FPG and myopic progression are more likely to have IOP elevation over time.

Prevalence of age-related macular degeneration in rural southern China: the Yangxi Eye Study.

PURPOSE: To describe the prevalence of age-related macular degeneration (AMD) among older adults in rural southern mainland China. METHODS: Eligible persons aged 50 years or over were identified by geographically defined cluster sampling from Yangxi County, Guangdong Province, China. Participants underwent a standardised interview and comprehensive eye examinations from August to November in 2014. Digital retinal photographs were graded for AMD lesions using the Clinical Classification of Age-Related Macular Degeneration developed by the Beckman Initiative for Macular Research Classification Committee. Age-standardised prevalence of AMD and AMD lesions was calculated using the 2010 world population data and compared with those of other populations. RESULTS: Of 5825 subjects who participated (90.7% response rate), 4881 (83.8%) had fundus photographs gradable for AMD. Early, intermediate and late AMD were present in 2003 (41.0%), 879 (18.0%) and 42 (0.86%) participants. The age-standardised prevalence of early, intermediate and late AMD was 40.4% (95% CI 39.6% to 41.2%), 17.6% (95% CI 17.0% to 18.2%) and 0.79% (95% CI 0.65% to 0.95%), respectively. Total AMD was more prevalent in men than in women (62.8% vs 57.1%). CONCLUSIONS: AMD is an important public health concern for rural southern China, and the prevalence of AMD was higher in men than in women.

Association of Socioeconomics With Prevalence of Visual Impairment and Blindness.

Importance: Vision loss is the third most common impairment worldwide. Although cost-effective interventions are available for preventing or curing most causes of vision loss, availability of these interventions varies considerably between countries and districts. Knowledge of the association between vision loss and socioeconomic factors is informative for public health planning. Objectives: To explore correlations of the prevalence of visual impairment with socioeconomic factors at country levels and to model and estimate a socioeconomic-adjusted disease burden based on these data. Design, Setting, and Participants: In this cross-sectional study, the following data were collected from 190 countries and territories: the age-standardized prevalence of moderate to severe visual impairment (MSVI) and blindness from January 1 to December 31, 2010, across countries, human development index (HDI), gross domestic product (GDP) per capita, total health expenditure, total health expenditure as percentage of GDP (total health expenditure/GDP), public health expenditure as percentage of total health expenditure (public/total health expenditure), and out-of-pocket expenditure as percentage of total health expenditure (out-of-pocket/total health expenditure). Countries were divided into 4 levels (low, medium, high, and very high) by HDI. Data analysis was conducted from September 1, 2016, to July 1, 2017. Main Outcomes and Measures: The correlations between prevalence data and socioeconomic indices were assessed. Results: A strong negative association between prevalence rates of MSVI and blindness and socioeconomic level of development was observed. The mean (SD) age-standardized prevalence of MSVI decreased from 4.38% (1.32%) in low-HDI regions to 1.51% (1.00%) in very-high-HDI regions (P < .001). The national HDI level was attributable to 56.3% of global variation in prevalence rates of MSVI and 67.1% of global variation in prevalence rates of blindness. Higher prevalence rates were also associated with lower total health expenditure per capita, total health expenditure/GDP (ß = −0.236 [95% CI, −0.315 to −0.157] for prevalence of MSVI; ß = −0.071 [95% CI, −0.100 to −0.042] for prevalence of blindness), public/total health expenditure (ß = −0.041 [95% CI, −0.052 to −0.031] for prevalence of MSVI; ß = −0.014 [95% CI, −0.018 to −0.010] for prevalence of blindness), and higher percentage of out-of-pocket/total health expenditure (ß = 0.044 [95% CI, 0.032-0.055] for prevalence of MSVI; ß = 0.013 [95% CI, 0.009-0.017] for prevalence of blindness). Countries with increased burden of visual impairment and blindness can be easily identified by the results of the linear models. Socioeconomic factors could explain 69.4% of the global variations in prevalence of MSVI and 76.3% of the global variations in prevalence of blindness. Conclusions and Relevance: Burden of visual impairment and socioeconomic indicators were closely associated and may help to identify countries requiring greater attention to these issues. The regression modeling described may provide an opportunity to estimate appropriate public health targets that are consistent with a country's level of socioeconomic development.

Prevalence and risk factors of epiretinal membranes: a systematic review and meta-analysis of population-based studies.

OBJECTIVE: This study was to aggregate the prevalence and risks of epiretinal membranes (ERMs) and determine the possible causes of the varied estimates. DESIGN: Systematic review and meta-analysis. DATA SOURCES: The search strategy was designed prospectively. We searched PubMed, Embase and Web of Science databases from inception to July 2016. Reference lists of the included literatures were reviewed as well. STUDY SELECTION: Surveys published in English language from any population were included if they had a population-based design and reported the prevalence of ERM from retinal photography with or without optical coherence tomography. Eligibility and quality evaluation was conducted independently by two investigators. DATA EXTRACTION: The literature search generated 2144 records, and 13 population-based studies comprising 49 697 subjects were finally included. The prevalence of ERM and the ORs of potential risk factors (age, sex, myopia, hypertension and so on) were extracted. RESULTS: The pooled age-standardised prevalence estimates of earlier ERM (cellophane macular reflex (CMR)), advanced ERM (preretinal macular fibrosis (PMF)) and any ERM were 6.5% (95% CI 4.2% to 8.9%), 2.6% (95% CI 1.8% to 3.4%) and 9.1% (95% CI 6.0% to 12.2%), respectively. In the subgroup analysis, race and photography modality contributed to the variation in the prevalence estimates of PMF, while the WHO regions and image reading methods were associated with the varied prevalence of CMR and any ERM. Meta-analysis showed that only greater age and female significantly conferred a higher risk of ERMs. CONCLUSIONS: Our findings suggest that ERMs are relatively common among aged population. Race, image taking and reading methodology may play important roles in influencing the large variability of ERM prevalence estimates.

A Global View on Output and Outcomes of Cataract Surgery With National Indices of Socioeconomic Development.

Purpose: Cataract blindness accounts for a substantial proportion of blindness worldwide. Understanding the correlations between national levels of socioeconomic development with the quantity and quality of cataract surgery may provide insight for the prioritization and resource allocation for blindness prevention programs. Methods: The relationships between human development index (HDI), gross domestic product (GDP) per capita, and cataract surgical coverage (CSC) and visual outcome of cataract surgery were examined in a multinational study utilizing secondary data from the repository for Rapid Assessment of Avoidable Blindness (RAAB), World Health Organization, Global Burden of Disease, United Nations, and the World Bank. Results: A total of 266 RAAB studies across 73 countries/territories were retrieved. Linear regression model results revealed strong associations of HDI with prevalence of cataract blindness (ß = -7.056, P < 0.001), CSC (ß = 60.808, P = 0.004), proportion of intraocular lens (IOL) implantation (ß = 87.040, P = 0.001), and proportion of cases with good vision outcomes among operated eyes (ß = 73.351, P < 0.001) in studies performed between 1995 and 2009. Similar associations were observed for studies performed between 2010 and 2015. In addition, countries with lower GDP per capita showed a higher rate of cataract blindness (ß = -0.527, P = 0.001), lower CSC (ß = 9.800, P < 0.001), lower percentage of IOL implantation (ß = 6.871, P = 0.001), and fewer patients with good vision outcomes after surgery (ß = 7.959, P < 0.001). After controlling survey year, country, and other factors, GDP per capita and HDI were also found to be significantly associated with CSC and visual outcomes after cataract surgery (all P < 0.05). Conclusions: We documented the strong associations of socioeconomic indices with quantity and quality of cataract surgery. These socioeconomic indicators should be considered as important factors for developing strategies aimed to improve worldwide cataract surgery service delivery.

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

PURPOSE: To investigate the progression of near vision loss and the cumulative incidence of near vision impairment (NVI) 6 years after initial examination of an urban Chinese cohort. DESIGN: Population-based, prospective cohort study. PARTICIPANTS: People aged ≥35 years examined at baseline in the Yuexiu District of Guangzhou, China. METHODS: Participants examined at baseline were invited for 2-year and 6-year follow-up examinations in 2010 and 2014, respectively. Examinations included noncycloplegic autorefraction and binocular near visual acuity (NVA) with and without current near correction measured at 40 cm using a LogMAR ETDRS near vision tumbling E chart. Those with uncorrected binocular NVA (UCNVA) ≤20/40 underwent subjective refraction to obtain best-corrected binocular NVA (BCNVA). MAIN OUTCOME MEASURES: Change in UCNVA between baseline and 2014 follow-up examinations and the 6-year cumulative incidence of vision impairment based on 3 definitions: NVA ≤20/40, ≤20/50, and ≤20/63. RESULTS: Among the 1817 baseline participants, 1595 (87.8%) were reexamined in 2010 and 1427 (78.5%) in 2014. Mean vision loss between baseline and the 2014 follow-up was 1.54 (±1.74) lines of UCNVA. Vision loss was associated with age 80 years or older, less education, and better baseline UCNVA. The 6-year cumulative incidence of uncorrected binocular NVI (UCNVI) across the 3 vision impairment definitions was 55.2% (95% confidence interval [CI], 46.1%-64.3%), 51.3% (95% CI, 44.0%-58.7%), and 42.4% (95% CI, 35.5%-49.3%), respectively. With best-corrected binocular NVI (BCNVI), incidence was 6.89% (95% CI, 4.28%-9.50%), 5.17% (95% CI, 2.89%-7.44%), and 2.62% (95% CI, 1.11%-4.12%), respectively. A higher incidence of UCNVI was associated with worse baseline UCNVA for all 3 impairment definitions. Similarly, incidence of BCNVI was associated with worse baseline BCNVA, but also with older age and education at the primary level or less. Gender was not significant for either UCNVI or BCNVI. CONCLUSIONS: Approximately half of those aged 35 years or older develop UCNVI in 6 years, the overwhelming majority of whom can be corrected with spectacles. Cost-effective strategies to provide spectacles to this at-risk population remains an issue requiring further study.

Cataract Surgical Rate and Socioeconomics: A Global Study.

PURPOSE: Cataract is the leading cause of blindness and cataract surgical rate (CSR) is used as a proxy indicator of access to cataract services in a country. The aim of this study was to explore the associations between the CSR and the economic development of countries in terms of gross domestic product per capital (GDP/P) and gross national income per capita (GNI/P). METHODS: We systematically searched OVID (Medline and Embase), Pubmed, Embase.com, ISI Web of Science, and Cochrane Library databases, and retrieved additional data from unpublished reports. Cataract surgical rates and economic indicators (GDP/P, GNI/P) were collected for each country from 2005 to 2014. Complete data were used for the 50 largest countries according to World Health Organization (WHO) population estimates. Linear correlations between GDP/P and CSR were calculated. Cataract surgical rate data over two periods were used for analysis: 2005 to 2009 and 2010 to 2014 (CSR in 2009 or nearest year, CSR in 2014 or nearest year). RESULTS: Over the study period, CSR data were available for 152 countries across both time periods. Most of the CSR data were obtained from nongovernment organization (NGO) reports, including WHO reports. A good linear correlation between CSR and GDP/P was found overall, nearest to 2009 (ß = 0.162, Linear: y = 0.162x + 282.242; R2 = 0.665, P < 0.001). Regression analysis of CSR nearest to 2014 produced similar findings, with significant correlations between CSR and GDP/P (Linear: y = 0.208x + 94.008; R2 = 0.785, P < 0.001). When using GNI/P as an economic indicator, similarly excellent lines of fit were obtained. After adjusting for time and country, CSR was significantly associated with GDP/P (Coefficient = 0.147, R2 = 0.759, P < 0.001), and GNI/P (Coefficient = 0.152, R2 = 0.757, P < 0.001). Most countries had an increase in CSRs over time, with the greatest increases observed for Iran and Argentina. CONCLUSION: Cataract surgical rate and economic indicators are closely associated, indicating the strong influence of resource availability on healthcare delivery. Considering this relationship, it is important to be innovative in delivery of low-cost services and invest strategically in capacity development to meet cataract surgical need in low-resource settings.

What Twin Studies Have Taught Us About Myopia.

Myopia has become epidemic, particularly in East Asia, and is a major cause of visual impairment worldwide. Twin studies are an important resource to investigate the genetics and the gene-environment interaction in myopia. This article aims to provide an overview of major findings regarding myopia from different types of twin studies, from the heritability of myopia-related traits to novel findings of genome-wide association studies. In the postgenomic era, twin studies will continue to serve as a unique method in the investigation of gene-environment interaction.