Relationship between socioeconomic and lifestyle factors and cataracts in Koreans: the Korea National Health and Nutrition Examination Survey 2008-2011

Prevalence of Selected Ophthalmic Diseases Using a Smartphone-Based Fundus Imaging System in Quang Tri and Thai Nguyen, Vietnam

OBJECTIVES

This study investigated the prevalence of ophthalmic diseases in Quang Tri and Thai Nguyen, Vietnam, utilizing a smartphone-based fundus imaging (SBFI) system.

METHODS

This cross-sectional study included nearly 10,000 patients who visited community health centers between July and August 2019. All participants underwent visual acuity testing and fundus imaging. We collected demographic data and medical histories, and fundus images were captured using the EYELIKE system. Data were compiled on an online platform, allowing clinicians from other regions to make diagnoses.

RESULTS

The study revealed significant variations in visual acuity and the prevalence of ophthalmic diseases between the two regions. Quang Tri had a higher proportion of individuals with good eyesight compared to Thai Nguyen. In Quang Tri, nearly 50% of the population had media haze, while in Thai Nguyen, about one-third of the population was affected. The prevalence of glaucomatous optic nerve and age-related macular degeneration was approximately 1% higher in Quang Tri than in Thai Nguyen. These findings provide valuable insights into the eye health status of these regions, indicating that eye health in Quang Tri was poorer than in Thai Nguyen.

CONCLUSIONS

The prevalence rates of ophthalmic conditions in this study were within the expected ranges compared to those in other Asian countries, though they were somewhat low. The SBFI method, being simpler and more efficient than the Rapid Assessment of Avoidable Blindness, offers a promising approach for measuring and estimating the prevalence of ophthalmic diseases.

Progress in the Application of Microneedles in Eye Disorders and the Proposal of the Upgraded Microneedle with Spinule

PURPOSE

In the local administration methods for treating eye diseases, the application of microneedles has great potential due to the shortcomings of low efficacy and significant side effects of local administration preparations. This article provides ideas for the research on the application of ophthalmic microneedle in the treatment of eye diseases.

RESULTS

This article analyzes the physiological structures of the eyes, ocular diseases and its existing ocular preparations in sequence. Finally, this article reviews the development and trends of ocular microneedles in recent years, and summarizes and discusses the drugs of ocular microneedles as well as the future directions of development. At the same time, according to the inspiration of previous work, the concept of "microneedle with spinule" is proposed for the first time, and its advantages and limitations are discussed in the article.

CONCLUSIONS

At present, the application of ocular microneedles still faces multiple challenges. The aspects of auxiliary devices, appearance, the properties of the matrix materials, and preparation technology of ophthalmic microneedle are crucial for their application in the treatment of eye diseases.

Association between cataract and fatty liver diseases from a nationwide cross-sectional study in South Korea

This study examined the link between fatty liver disease (FLD) and cataracts, as previous research has suggested that FLD may contribute to metabolic syndrome, systemic inflammation, and potentially cataracts. We studied a nationwide cross-sectional cohort of the Fifth Korean National Health and Nutrition Examination Survey 2010-2011. FLD was defined as nonalcoholic FLD (NAFLD) and metabolic dysfunction-associated FLD (MAFLD). Multinomial logistic regression was utilized to investigate the relationship between cataracts and FLD after adjustment for potential confounders. Participants with cataracts had higher liver fibrosis scores, including the NAFLD fibrosis score (NFS; P < 0.001), fibrosis-4 index (FIB4; P < 0.001), and fatty liver index (FLI; P = 0.001). NAFLD was not associated with a higher odds ratio (OR) for cataracts in the fully adjusted model (OR = 1.23, P = 0.058). MAFLD was significantly associated with a higher OR (OR = 1.34, P = 0.006). After adjusting for all factors, the severity of FLD was linked to an increased risk of cataracts, with significant linear trends (P values for linear trends of NFS, FIB4, and FLI < 0.05). After adjusting for well-known cataract risk factors, MAFLD was significantly associated with cataracts. Our analysis suggests that FLD may serve as an independent risk factor for cataracts.

Changing Trends in the Global Burden of Cataract Over the Past 30 Years: Retrospective Data Analysis of the Global Burden of Disease Study 2019

BACKGROUND

Cataracts now account for the largest proportion of the global burden of blindness and vision loss. Understanding the changing trends in the global burden of cataracts over the past 30 years and the next 15 years is of clear significance for the prevention and control of cataracts in key populations. As far as we know, research on the future burden of cataracts is lacking.

OBJECTIVE

This study aims to assess the global burden of cataracts over the past 30 years by using age-period-cohort modeling and to estimate trends in the next 15 years.

METHODS

Data were obtained from the Global Burden of Disease Study 2019, the United Nations Development Programme, and the WHO (World Health Organization) Global Health Observatory data repository. The assessment of trends and disparities in the number and rate of disability-adjusted life years (DALYs) for cataracts from 1990 to 2019 was conducted. The association between the age-standardized DALY rate (ASDR) and the socio-demographic index (SDI), human development index (HDI), national levels of particulate matter <2.5 μm in diameter (PM2.5), and ambient ultraviolet radiation (UVR) was determined using linear regression analysis. Additionally, we used the Nordpred (Harald Fekjær and Bjørn Møller) age-period-cohort model to predict the cataract burden from 2020 to 2034.

RESULTS

Globally, the number of DALYs due to cataract increased from 3,492,604 (95% uncertainty interval [UI] 2,481,846-4,719,629) in 1990 to 6,676,281 (95% UI 4,761,210-9,006,193) in 2019. The ASDRs due to cataract decreased from 93.17 (95% UI 66.14-125.32) in 1990 to 82.94 (95% UI 59.06-111.75) in 2019, with an average annual percentage change of -0.37 (95% CI -0.44 to -0.3; P<.001). Age, female sex, air pollution, smoking, high fasting plasma glucose levels, and a high body mass index were risk factors for the burden of cataracts. SDI and HDI were negatively correlated with ASDRs of cataracts, while PM2.5 and UVR were positively associated with them. Higher DALY rates were also associated with lower SDI (R2=0.1939; P<.001), lower HDI (R2=0.2828; P<.001), national PM2.5 concentration (R2=0.1874; P<.001), and ambient UVR levels (R2=0.2354; P<.001). The prediction model suggested that the number of DALYs due to cataract will continue to rise globally, while the cataract DALY rate will continue to decrease.

CONCLUSIONS

While the ASDR of cataracts has decreased, there has been a notable increase in the number of DALYs over the past 30 years. Projections suggest that the global burden of cataracts will continue to rise over the next 15 years. To address this challenge, appropriate prevention and treatment policies must be implemented.

Investigation of the antioxidant effect of Chrysin in an experimental cataract model created in chick embryos

PURPOSE

Cataract, which occurs as a result of lens opacification, is one of the most common causes of vision loss. In the literature, deterioration of the antioxidant system due to the increase in reactive oxygen species and oxidant levels is shown among the causes of cataract formation. The aim of this study was to investigate the antioxidant effect of chrysin on steroid-induced cataract development in an experimental chick embryo model using morphological, histological and biochemical parameters.

METHODS

Within the scope of the study, 150 specific pathogen free (SPF) fertilized eggs were used. Eggs were divided into 6 groups as control (group 1), corn oil (group 2), hydrocortisone hemisuccinate sodium (HC) (group 3), low dose chrysin (group 4), medium dose chrysin (group 5) and high dose chrysin (group 6). On the 15th day of incubation, Chrysin and HC were applicated to the air sac of the eggs with Hamilton and/or insulin injector. On day 17, the chick embryos were removed from the eggs and the bulbus oculi of the embryos were dissected. Lenses of 9 embryos were used for morpholigical cataract grading in each group, lens of 8 embryos for biochemical analysis and intact eyes of 7 embryos for histological evaluation (TUNEL method).

RESULTS

No opacity was observed in any of the lenses in Group 1 and 2. Cataract was observed in all lenses in Group 3. The mean opacity grades in group 3 were statistically significantly higher when compared to group 1 and 2 (p<0.05). The difference between group 6 and group 3 was statistically significant (p<0.05). GSH and TAS levels in the lenses were statistically significantly decreased compared to the control group due to HC application (p<0.05). It was determined that the decreased GSH and TAS levels in the lenses increased in relation to the Chrysin application doses. The increased levels of MDA, TOS, caspase 3 and caspase 9 in the HC group decreased significantly depending to the chrysin doses (p<0.05). In addition, while the rate of apoptotic cells determined by the TUNEL method was statistically significantly higher in the HC administered group than in the control group (p<0.05), it was statistically significantly decreased in the chrysin-administered groups, in relation to the dose of chrysin (p<0.05).

CONCLUSIONS

We think that anti-cataract effect of crhysin may be due to the antioxidant and antiapoptotic properties of chrysin. However, more research is needed to clarify the anti-cataract effects of chrysin.

Long-Term Exposure to Ambient PM2.5 and Age-Related Cataracts among Chinese Middle-Aged and Older Adults: Evidence from Two National Cohort Studies

Cataract is one key cause of visual disability and blindness. Ambient particulate matter is more likely to increase cataract risk due to eye continuous exposure to the environment. However, less is known about whether long-term exposure to particulate matter 2.5 (PM2.5) is related to age-related cataracts. We conducted a population-based study among 22,298 adults from two multicenter cohort studies [China Family Panel Studies (CFPS) and Chinese Longitudinal Healthy Longevity Survey (CLHLS)]. The associations between PM2.5 and age-related cataracts were analyzed by Cox proportional hazard regression models, which were also stratified according to demographic characteristics. The restricted cubic spline (RCS) model was used to explore the dose-response relationships between PM2.5 and age-related cataracts. The population attributable fraction (PAF) was calculated to assess the burden of age-related cataracts that can be attributed to PM2.5. In the final analysis, 1897 participants reported age-related cataracts during follow-up. Long-term exposure to PM2.5 was associated with age-related cataracts, with HRs of 1.165 (1.130, 1.201), 1.138 (1.103, 1.173), and 1.091 (1.057, 1.126) for per 10 μg/m3 increase at one-, two-, and three-year before the end of follow-up, respectively. Furthermore, associations between PM2.5 and age-related cataracts were also demonstrated in RCS models. The PAF of age-related cataracts to PM2.5 in the total participants was 24.63%. Our research found that long-term exposure to PM2.5 may increase the risk of age-related cataracts, and age-related cataracts should be considered as an important public health issue due to air pollution.

The Risk of Major Depressive Disorder Due to Cataracts among the Korean Elderly Population: Results from the Korea National Health and Nutrition Examination Survey (KNHANES) in 2016 and 2018

Cataracts and major depressive disorder (MDD) both have high prevalence, representing for major health burdens globally. In this study, we examined the risk of MDD due to cataracts. Data from the 2016 to 2018 Korea National Health and Nutrition Examination Survey (KNHANES) were used, including 4122 participants. Logistic regression analysis was performed to evaluate the odds ratio for MDD in association with cataracts. Controlled variables were age, gender, smoking, dyslipidemia and mobility. Subgroup analysis was performed with stratification by gender. The results reveal that cataracts are significantly correlated with MDD. Elderly people with cataracts were found to be more likely to develop MDD compared to those without cataracts (adjusted odds ratio: 1.654; 95% CI = 1.197-2.286). In subgroup analysis, men (adjusted odds ratio: 2.631; 95% CI = 1.247-5.551) were found to be more likely to develop MDD than women (adjusted odds ratio: 1.510; 95% CI = 1.061-2.150). Cataracts may be a risk factor for MDD in the elderly, especially among the male population.

Socioeconomic disadvantage and impact on visual outcomes in patients with viral retinitis and retinal detachment

While socioeconomic disparities impact clinical care and patient outcomes, their impact on the anatomic and visual outcomes of retinal detachment in patients with viral retinitis is unstudied. This case series included 18 eyes in 18 patients from a single academic institution between January 1, 2008 and December 31, 2018. Patient characteristics including age, sex, race, ethnicity, insurance, immunosuppression, viral retinitis, retinal detachment, retinal detachment repair, visual and anatomic outcomes, missed appointments, and Area Deprivation Index [ADI] were collected. The low-ADI group, indicating less socioeconomic disadvantage, was comprised of twelve patients with national ADIs less than 38, and the high-ADI group of six patients with national ADIs greater than 38. High-ADI patients tended to be younger (average age 38.0 versus 51.3; P = 0.06), of female sex (P = 0.03), and had more missed appointments (median 11.0 vs 0; P = 0.002). A similar number of patients in both the high-ADI and low-ADI groups underwent pars plana vitrectomy alone or pars plana vitrectomy with scleral buckle. Visual acuity was similar in the high-ADI group than in the low-ADI group at baseline, but worse at the final follow-up visit (P = 0.004). Post-operative and final visit ocular hypotony were more common in the high-ADI group (P = 0.02). In our series, socioeconomic disadvantage negatively affects the visual outcomes in patients with viral retinitis associated-retinal detachments. These factors should be considered by ophthalmologists when treating these patients.

Live surgery outcomes in cataract surgery

PURPOSE

To evaluate and compare the outcomes of live surgery (LS) and no-live surgery (NLS) on cataract surgery with implantation of different types of intraocular lenses (IOLs).

METHODS

Retrospective, contralateral eye, case series of patients that underwent cataract surgery in live or non-live view during two consecutive editions of national meetings. Both eyes of the same patients were implanted with the same IOL, one in LS and the other in NLS.

RESULTS

108 eyes of 54 patients, aged between 50 and 82 (72 ± 8.2) and implanted with different types of IOLs, were reviewed. Both eyes in each patient were well matched at baseline in terms of intraocular biometric characteristics, corneal curvature and endothelial cell density (ECD) (p > 0.05). There are no statistically significant differences between the biometric and topographic parameters, aberrometric data and the loss of ECD in the post-operative outcomes (p > 0.05). However, comparing the different types of IOLs, there is a significant loss of ECD in eyes implanted with a toric IOL during LS (p = 0.0014 and p = 0.04, in 2017 and 2018 edition respectively).

CONCLUSIONS

In this series of live cataract surgery, eyes operated in LS or NLS have comparable outcomes, underlying the importance and the benefits of live view in terms of medical education and the low-risk of complications. Nevertheless, we have found a significant increase in ECD loss in patients implanted with toric IOLs during LS.

EPIRETINAL MEMBRANE SURGERY IN PATIENTS WITH MULTIFOCAL VERSUS MONOFOCAL INTRAOCULAR LENSES

PURPOSE

To compare the visual/anatomical outcomes and feasibility of epiretinal membrane surgery between patients with multifocal or monofocal intraocular lenses (IOLs).

METHODS

We reviewed the medical records of 46 patients who underwent epiretinal membrane surgery under multifocal or monofocal IOL pseudophakia. The operation time, mean changes in best-corrected visual acuity, and central macular thickness, and complications were compared between the groups.

RESULTS

Macular surgery was performed in 22 and 24 eyes with multifocal and monofocal IOLs, respectively. The total operation time and the total membrane peeling time were similar in both groups (P = 0.125, P = 0.462, respectively). The mean time to create a membrane edge or flap with retinal microforceps was longer for multifocal than for monofocal IOLs (P = 0.013). The mean changes in best-corrected visual acuity and central macular thickness were similar in both groups (P = 0.682, P = 0.741, respectively). Complications were similar between groups.

CONCLUSION

With multifocal IOLs, vision outside the central surgical field was blurred, requiring more time to create the membrane flap. Retinal surgeons should anticipate the difficulty in precise focusing when creating a membrane flap in macular surgery in patients with multifocal IOLs and should pay more attention to the macular surgery.

Hyperglycemia and Hypo-HDL-cholesterolemia Are Primary Risk Factors for Age-related Cataract, and a Korean-style Balanced Diet has a Negative Association, based on the Korean Genome and Epidemiology Study

BACKGROUND

The prevalence of cataracts is steadily increasing among the middle-aged and elderly worldwide. We hypothesized that adults aged > 50 years with age-related cataracts (ARCs) have an association with metabolic syndrome (MS) and its components, and MS has interactions with different dietary patterns and lifestyles that affect ARC risk. We examined the hypothesis using the Korean Genome and Epidemiology Study (KoGES; a large-scale hospital-based cohort study), which collected data between 2004-2013.

METHODS

Participants ≥ 50 years old were classified as cases (1,972 ARC patients) and controls (38,290 healthy controls) based on a diagnosis of cataract by a physician. MS and its components were defined using WHO definitions for Asians. Dietary consumption was evaluated using a validated semi-quantitative food frequency questionnaire (SQFFQ), which contained 106 foods, and dietary patterns were analyzed by principal component analysis. After adjusting for potential covariates, logistic regression was used to investigate associations between MS and its components and between dietary patterns and a positive cataract history.

RESULTS

ARC had a positive association with MS after 1.32-fold adjusting for age, sex, residence area, body mass index, and energy intake. Plasma glucose and HbA1c concentrations exhibited an increased ARC risk in the participants with MS by 1.50- and 1.92-fold and without MS by 1.35 and 1.88-fold, respectively. Serum high-density lipoprotein (HDL) concentrations were negatively associated with ARC risk only in the MS patients, but not without MS. However, blood pressure, abdominal obesity, and serum triglyceride concentrations did not associate with ARC risk regardless of MS. High intake of a Korean-balanced diet (KBD) containing fermented food exhibited a negative association with ARC risk (OR = 0.81) only in the MS group. The fat and coffee intake had a negative association with ARC only in the non-MS group. Current- and former-smokers were positively associated with ARC risk.

CONCLUSION

Persons who have hyperglycemia and low-HDL-cholesterolemia had increased susceptibility of ARC prevalence. A KBD with a proper amount of fat (≥ 15%) is recommended, and smoking should be prohibited.

Sociodemographic Factors Influencing Rhegmatogenous Retinal Detachment Presentation and Outcome

PURPOSE

The impact of sociodemographic factors on the presentation and outcomes of rhegmatogenous retinal detachment (RRD) in the United States has not been described. We analyzed the impact of these factors on the presenting fovea-on or off status of RRD, single operation anatomic success (SOAS) of repair, and postoperative visual acuity (VA).

DESIGN

Retrospective, single-center, cohort study.

PARTICIPANTS

Participants included 4061 patients from Wills Eye Hospital/Mid Atlantic Retina from February 2015 to February 2020.

METHODS

Sociodemographic factors including age, gender, race, and regional mean household income (MHI) as determined by ZIP code were recorded. The VA at baseline and 12 months post-RRD repair was recorded. Multiple regression analysis was used to evaluate the relationship between sociodemographic factors to fovea-on or off presentation of RRD, SOAS, and 12-month VA.

MAIN OUTCOME MEASURES

Foveal attachment at presentation of RRD, SOAS, and 12-month VA.

RESULTS

Older age (odds ratio [OR], 1.34 per decade, 95% confidence interval [CI], 1.27-1.41, P < 0.001), male gender (OR, 1.27, 95% CI, 1.11-1.45, P < 0.001), non-White race (OR, 2.41, 95% CI, 1.92-3.03, P < 0.001), and lower MHI (OR, 0.94 per $10 000, 95% CI, 0.91-0.98, P = 0.005) were independent risk factors for fovea-off presentation of RD. The need for reoperation to repair RRD within 90 days was independently associated with fovea-off presentation (OR, 1.47, 95% CI, 1.24-1.74, P < 0.001) and non-White race (OR, 1.72, 95% CI, 1.27-2.39, P < 0.001). Finally, 12-month postoperative VA was worse in patients who were fovea-off (P < 0.001), older (P = 0.041), male (P = 0.038), and non-White (P = 0.007) but was not related to MHI (P = 0.24).

CONCLUSIONS

These findings reveal associations between the sociodemographic factors and the presentation and outcomes of RRD. Physicians should be aware that socioeconomic disparities can negatively impact the prognosis of patients with RRD. Further study confirming these findings and efforts to mitigate their effects are warranted and will be of interest to the greater ophthalmology community.

Socioeconomic and physical health status changes after visual impairment in Korea using difference-in-difference estimations

This study analyzed the impact of visual impairment on socioeconomic and physical health status and its heterogeneity by severity of visual impairment. We used nationally representative cohort data based on Korean national health insurance claims (2002–2013), which were extracted for 11,030 persons (2206 visually impaired, 8824 control). This was restructured as monthly data for each person (person-month). Multivariate and ordered logistic regressions were conducted, and the pre-impairment status between the visually impaired and non-visually impaired people was adjusted by difference-in-difference (DiD) estimation. Focusing on medical aid (a public healthcare service assistance program for people who cannot afford health insurance premiums), the DiD estimate showed that the likelihood of receiving aid was higher among visually impaired compared with non-impaired people. Mildly and severely visually impaired people were more likely to be medical aid recipients than their counterparts. The severely visually impaired group was more likely to be unemployed. The visually impaired group were less likely to have no comorbidity. Our findings show that the socioeconomic and physical health status of visually impaired people is more likely to deteriorate than that of their non-visually impaired counterparts following onset of impairment.

Association between Exposure to Ambient Air Pollution and Age-Related Cataract: A Nationwide Population-Based Retrospective Cohort Study

This study aimed to investigate the association between ambient air pollutants and cataracts in the general population aged 50 years or older using data from the Korean National Insurance Service-National Sample Cohort. Cataract patients were defined as those diagnosed by a physician and having undergone cataract surgery. After matching the average concentrations of PM2.5, PM10, NO2, CO, SO2, and O3 in residential areas, the association between quartile level of air pollutants and incidence of cataract was analyzed using a multivariate Cox-proportional hazard risk model. Among the 115,728 participants, 16,814 (14.5%) were newly diagnosed with cataract and underwent related surgery between 1 January 2004, and 31 December 2015. Exposure to PM10, NO2, and SO2 was positively associated with cataract incidence, while O3 was negatively associated. The adjusted hazard ratio (HR) with 95% confidence interval was 1.069 (1.025-1.115) in PM10 and 1.080 (1.030-1.133) in NO2. However, the association between cataract and the quartile of PM2.5 measured during one year in 2015 was not clear. The HR of female participants aged 65 or older was significantly increased according to quartile of air pollutants. We identified exposure to PM10, NO2, SO2, and O3 associated with cataract development in Korean adults aged ≥ 50 years. This information may be helpful for policymaking to control air pollution as a risk factor for eye health.

Global and regional prevalence of age-related cataract: a comprehensive systematic review and meta-analysis

The aim of our study was to estimate regional and global cataract prevalence, its prevalence in different age groups, and the determinants of heterogeneity and its prevalence. For that, we used international databases such as PubMed, Web of Science, Scopus, Embase, and other sources of information to conduct a systematic search for all articles concerning the prevalence of age-related cataract and its types in different age groups. Of the 9922 identified articles, 45 studies with a sample size of 161,947 were included in the analysis, and most of them were from the Office for the Western Pacific Region (19 studies). Age- standardized pooled prevalence estimate (ASPPE) and 95% confidence interval (95% CI) of any cataract, cortical cataract, nuclear cataract, and posterior subcapsular (PSC) cataract were 17.20% (13.39-21.01), 8.05% (4.79-11.31), 8.22% (4.93-11.52), and 2.24% (1.41-3.07), respectively. Significant effects on heterogeneity were observed for the WHO region in the prevalence of any cataract (b: 6.30; p: 0.005) and study year in the prevalence of nuclear cataract (b: -0.66, p: 0.042). In general, the prevalence of cataract not only varies by region but also by age group, and most cases are over the age of 60 years. We examined the sources of variance in the prevalence of cataract and its different types, and identified age as a responsible factor in the prevalence of any cataract, cortical cataract, nuclear cataract, and PSC of cataract, WHO region in the prevalence of any cataract, and study year in the prevalence of nuclear cataract.

Horizontal inequity in the utilization of cataract surgery in Iran: Shahroud Eye Cohort Study, 2009-2014

Background: Since there was no evidence about economic inequity in utilization of cataract surgery in developing countries, such as Iran, this study was designed to measure horizontal inequity in the utilization of cataract surgery and its changes in an Iranian middleaged population in 2009 and 2014. Methods: Using data from the first and second phases of Shahroud Eye Cohort Study (2009-2014), the economic inequity in the utilization of cataract surgery in an Iranian middle-aged population aged 40-64 years in 2009 and 2014 was evaluated. The horizontal inequity index (HI) was determined using the indirect standardization method based on a nonlinear (probit) model and the concentration index (C) was decomposed into the contribution of each factor. The analyses were performed using STATA software version 12/SE, and significance level was set at less than 0.05. Results: The HI in the utilization of cataract surgery increased from 0.080 (95% CI: 0.011-0.098) in 2009 to 0.166 (95% CI: 0.0821- 0.228) in 2014. Decomposition of changes in the concentration index showed that among need and non-need variables, older age and economic status (being among the wealthiest 20%) were the greatest contributors, with shares of 67.5% and 57.5%%, respectively, which led to pro-rich inequity during the study periods. Conclusion: The present study demonstrated that utilization of cataract surgery did not have an equal distribution among economic quintiles, despite considering equal needs based on cataract severity. Results demonstrated that older age and economic status were the greatest contributors to HI increase in 2009 and 2014.

Risk of cataract in smokers: A meta-analysis of observational studies

OBJECTIVE

The aim of the study was to compare the risk of cataract in smokers and ex-smokers.

METHODS

A systematic search of observational studies was carried out in Medline, Embase, and Lilacs databases. Studies that have evaluated the association between cigarette smoking and any type of clinically diagnosed cataract were selected. The association estimators were extracted, adjusted at least by age, and were combined using random-effects models, by subtype of study (cohort, case control and cross sectional), subtype of cataract (nuclear, cortical, and posterior subcapsular), and exposure (current smoker or ex-smoker). Statistical heterogeneity, meta-regression analysis and publication bias were assessed.

RESULTS

A total of 13 cohort studies, 12 case-control studies, and 18 cross-sectional studies were selected. A risk of cataract was found in current smokers: cohort (OR: 1.41; 95%CI: 1.24-1.60), cases and controls (OR: 1.45; 95%CI: 1.08-1.96), and cross-sectional studies (OR: 1.21; 95%CI: 1.09-1.34); risk of nuclear cataract: cohort (OR: 1.71; 95%CI: 1.47-1.98), case-control (OR: 1.79; 95%CI: 1.43-2.25), and cross sectional studies (OR: 1.45; 95%CI: 1.27-1.65). There was no risk of cortical or posterior subcapsular cataract in ex-smokers.

CONCLUSIONS

There is a risk of cataract in smokers, particularly nuclear type. With cross-sectional studies, similar results are obtained with cohorts and cases and controls.

Unexpected potential protective associations between outdoor air pollution and cataracts

Air pollution is one of the biggest public health issues, and the eye is continuously exposed to multiple outdoor air pollution. However, to date, no large-scale study has assessed the relationship between air pollutants and cataracts. We investigated associations between outdoor air pollution and cataracts in the Korean population. A population-based cross-sectional study was performed using data from the Korea National Health and Nutrition Examination Survey, including 18,622 adults more than 40 years of age. The presence of cataracts and their subtypes were evaluated by ophthalmologists. Air pollution data (levels of particulate matter, ozone, nitrogen dioxide, and sulfur dioxide) for the 2 years prior to the ocular examinations were collected from national monitoring stations. The associations of multiple air pollutants with cataracts were assessed by multivariate logistic regression analyses. Sociodemographic factors and previously known risk factors for cataracts were controlled as covariates (model 1 included sociodemographic factors, sun exposure, and behavioral factors, while model 2 further included clinical factors). Higher ozone concentrations were protectively associated with overall cataract which included all subtypes [single pollutant model: 0.003 ppm increase-model 1 (OR 0.89, p = 0.014), model 2 (OR 0.87, p = 0.011); multi-pollutant model: 0.003 ppm increase-model 1 (OR 0.80, p = 0.002), model 2 (OR 0.87, p = 0.002)]. Especially, higher ozone concentrations showed deeply protective association with nuclear cataract subtype [0.003 ppm increase-single pollutant model: model 2 (OR 0.84, p = 0.006), multi-pollutant model: model 2 (OR 0.73, p < 0.001)]. Higher tropospheric ozone concentrations showed protective associations with overall cataract and nuclear cataract subtype in the Korean population.

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

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

Prevalence, Causes and Social Factors of Visual Impairment among Chinese Adults: Based on a National Survey

Visual impairment has become a global challenge, especially for developing countries. This study aims to estimate the prevalence, causes and social factors of visual impairment among Chinese adults. Data were from a nationally representative population-based cross-sectional study. The study population were 1,909,199 non-institutionalized adults aged 18 years and older in mainland China. In the survey, low vision and blindness were checked by ophthalmologists according to the WHO best-corrected visual acuity (BCVA) criteria. Population weighted numbers and prevalence of low vision and blindness with 95% confidence intervals (CIs) were estimated where appropriate. Multivariable logistic regression analysis was used to identify the social factors of visual impairment. The weighted prevalence of visual impairment was 17.17 (95% CI, 16.84-17.50) per 1000 Chinese adults aged 18 years and older. Cataract (57.35%), disorders of choroid and retina (9.80%), and disorders of cornea (6.49%) contributed more than 70 percent to the visual impairment in Chinese adults. Older age groups, young or middle-aged male adults, female elders, illiterate, rural dwellers, non-eastern residents, singles, unemployment, and from family with lower income were associated with visual impairment. More efforts are warranted to enhance treatment and rehabilitation among people with eye disorders to prevent visual impairment.

Prevalence and risk factors of lens opacities in rural populations living at two different altitudes in China

AIM

To investigate the prevalence of and risk factors for lens opacities in populations living at two different altitudes in China.

METHODS

A total of 813 subjects aged ≥40y in Lhasa (Tibet Autonomous Region, China. Altitude: 3658 m) and Shaoxing (Zhejiang Province, China. Altitude: 15 m) were underwent eye examinations and interviewed in this cross-sectional study. Participants' lens opacities were graded according to the Lens Opacities Classification System II (LOCS II) and the types of opacities with LOCS II scores ≥2 were determined. Univariate and stepwise logistic regression were used to evaluate the associations of independent risk factors with lens opacities.

RESULTS

Lens opacities were significantly more prevalent in the high-altitude than in the low-altitude area (χ (2)=10.54, P<0.001). Lens opacities appear to develop earlier in people living at high than at low altitude. The main types of lens opacity in Lhasa and Shaoxing were mixed (23.81%) and cortical (17.87%), respectively. Independent risk factors associated with all lens opacities were age, ultraviolet (UV) radiation exposure, and educational level. Compared with participants aged 40-49y, the risk of lens opacities increased gradually from 2 to 85 times per 10y [odds ratio (OR)=2.168-84.731, P<0.05). The risk of lens opacities was about two times greater in participants with the highest UV exposure than in those with the lowest exposure (OR=2.606, P=0.001). Educational level was inversely associated with lens opacities; literacy deceased the risk by about 25% compared with illiteracy (OR=0.758, P=0.041).

CONCLUSION

Old age, higher UV exposure and lower educational level are important risk factors for the development of lens opacities. Lens opacities are more prevalent among high-altitude than low-altitude inhabitants.