Association of Long-term Ambient Black Carbon Exposure and Oxidative Stress Allelic Variants With Intraocular Pressure in Older Men

Long-term exposure to PM2.5 and its constituents and visual impairment in schoolchildren: A population-based survey in Guangdong province, China

BACKGROUND

Exposure to fine particulate matter (PM2.5) has been linked to visual impairment. Nevertheless, evidence associating PM2.5 constituents with visual impairment in schoolchildren is sparse.

OBJECTIVES

To explore the effects of long-term exposure to PM2.5 and its constituents on visual impairment.

METHODS

We conducted a large cross-sectional population-based study to recruit 59,054 schoolchildren from four cities in Guangdong province, China, and used the ChinaHighAirPollutants (CHAP) dataset to estimate 3-year average concentrations of PM2.5 and its constituents (black carbon (BC), organic matter (OM), nitrate (NO3-), sulfate (SO42-) and ammonium (NH4+)) based on individuals' home addresses. Visual acuity was measured with a standardized logarithmic chart, and visual impairment was defined as visual acuity below 4.9 (Snellen 5/6 equivalent) in at least one eye. We utilized generalized linear mixed models and weighted quantile sum regression to assess the association between PM2.5 constituents and visual impairment.

RESULTS

The observed associations typically displayed a nonlinear pattern. Compared to the lowest quartile of PM2.5 and its constituents, the fourth quartile was associated with higher odds of visual impairment in schoolchildren (e.g., the adjusted odds ratio (OR) was 1.23 (95% CI: 1.13, 1.33) for PM2.5, 1.53 (95% CI: 1.40, 1.67) for OM, and 1.35 (95% CI: 1.27, 1.44) for BC), respectively. Similarly, joint exposure to PM2.5 constituents was associated with visual impairment (OR = 1.17, 95% CI: 1.13, 1.22), while BC and OM contributed more to the observed associations.

CONCLUSIONS

Long-term exposure to PM2.5 and its constituents was significantly associated with higher rates of visual impairment in schoolchildren, with combustion-related BC and OM potentially driving the observed associations.

Elevated serum uric acid levels mediate the associations of ambient PM2.5 and its components with glaucoma

Limited epidemiological information exists on the relationships between fine particulate matter (PM2.5) components and glaucoma risk. Moreover, the potential mediation effect of serum uric acid (UA) levels remains unexplored. Data from the China Health and Retirement Longitudinal Survey (CHARLS) spanning 2011-2020 were analyzed. Cox proportional hazard models and quantile-based g-computation (qg-computation) models were applied to determine the associations of PM2.5 and its five components (including sulfate [SO₄2⁻], nitrate [NO₃⁻], ammonium [NH₄⁺], organic matter [OM], and black carbon [BC]) with glaucoma risk. A causal mediation model was applied to assess the mediation effect of serum UA. Individual exposure to PM2.5 mass and its five components was positively associated with glaucoma risk, respectively. The mixture of PM2.5 components were significantly and positively associated with glaucoma risk (hazard ratio [HR] = 1.31, 95% confidence interval [CI]: 1.18-1.45), with NH₄⁺ and BC contributing the most (proportions: 81% and 19%, respectively). These associations were modified by sex and residence. Elevated serum UA levels played a mediated role in the association between PM2.5 mass and its five chemical components and glaucoma, with mediated proportions ranging from 12% to 15%. Prolonged exposure to PM2.5 components, especially NH4+ and BC, may elevate the glaucoma risk among Chinese middle-aged and older people, and elevated serum UA levels may play a key mediating role.

Association of Ambient Air Pollution Exposure With Incident Glaucoma: 12-Year Evidence From the UK Biobank Cohort

Purpose

Glaucoma is the leading cause of irreversible blindness worldwide. Despite growing concerns about air quality and its impact on ocular health, there remains a knowledge gap regarding the long-term association between air pollution and glaucoma risk. This study investigates the relationship between exposure to ambient air pollution and incidence of glaucoma.

Methods

In this prospective study, we used land use regression models to estimate levels of various air pollutants, including fine particulate matter (PM2.5), PM2.5 absorbance, PM2.5-10, PM10, nitrogen dioxide (NO2), and nitrogen oxides (NOx). Incidents of glaucoma were ascertained through routinely collected hospital admission records. Multivariate Cox proportional hazards models were used to examine the associations between air pollution exposure and glaucoma incidence, adjusting for potential confounding sociodemographic, physical, and lifestyle factors.

Results

Data from 481,113 participants were included. Over a median follow-up of 12.8 years, 9224 incident cases of glaucoma were identified. In the maximally adjusted model, per interquartile range increase in PM2.5 was associated with a 3% greater risk of developing glaucoma (hazard ratio [HR] = 1.03, 95% confidence interval [CI] = 1.00 to 1.06, P = 0.048). Participants in the highest quartile had a 10% increased risk of developing glaucoma compared to those in the lowest quartile (HR = 1.10, 95% CI = 1.03 to 1.17, P = 0.005).

Conclusions

Higher levels of exposure to ambient air pollutants, particularly PM2.5, are associated with an increased risk of developing glaucoma. These results highlight the potential public health impact of ambient air pollution on glaucoma risk and underscore the urgent need for further research into targeted environmental interventions in this domain.

The association between airborne particulate matter (PM2.5) exposure level and primary open-angle glaucoma

The eye is vulnerable to the adverse effects of air pollution. Previous experimental study found that fine particulate matter (PM2.5) had a direct toxic effect on intraocular tissues. However, clinical evidence for the impact of air pollutants exposure on functional and structural changes in glaucoma remains scarce. A total of 120 patients with primary open-angle glaucoma (POAG) who met the inclusion criteria were included in this retrospective study. The standardized ophthalmic examination, such as intraocular pressure (IOP), visual field, optical coherence tomography, and comprehensive physical examination, were performed. The air pollution data, including PM2.5 concentration and air quality index (AQI), were collected. PM2.5 and AQI for the day of the medical examination, as well as one month, and three months before the medical examination date, were investigated. In our results, higher average exposure levels for one-month and three-month, were associated with increased IOP (r=0.229, P=0.013; r=0.204, P=0.028, respectively) and decreased visual field mean sensitivity (MS) (r=-0.212, P=0.037; r=-0.305, P=0.002, respectively). PM2.5 concentrations for the day of the medical examination was not significantly associated with ocular parameters. In multiple linear regression analysis adjusted for demographic and clinical factors, higher PM2.5 exposure for one month was associated with elevated IOP (P=0.040, β=0.173, 95 %CI=0.008-0.337). We also found an association between PM2.5 and MS (one-month exposure: β=-0.160, P=0.029; three-month exposure: β=-0.238, P=0.002). The logistic regression analysis found that three-month average PM2.5 exposure level was significantly associated with the disease severity (β=0.043, P=0.025, 95 %CI=1.005-1.084). In conclusion, this study is the first to investigate the relationship between air pollution and detailed ocular parameters of POAG patients in Shanghai over a three-year period, and to explore the effects of different exposure times of PM2.5 on glaucoma. This study found that PM2.5 exposure was correlated with elevated IOP and decreased MS. The one-month PM2.5 exposure level had the most significant effects on IOP. The three-month PM2.5 exposure level was an independent risk factor for POAG severity. Current evidence suggests there may be an association between PM2.5 exposure and POAG.

The impact of air pollution and climate change on eye health: a global review

Climate change has important implications on human health, affecting almost every system in the body. Multiple studies have raised the possibility of climate change impacting eye health. In this review, we aimed to summarize current literature on the impact of air pollution and climate change on eye health. We performed a search in four different databases, including Medline, Scopus, Cochrane, and Web of Sciences databases. The search strategy combined terms regarding eye health and environmental/climate changes. The outcome of interest included all eye conditions. The search yielded 2,051 unique articles. After applying inclusion and exclusion criteria, 61 articles were included in this systematic review with data covering 2,620,030 participants. Most studies originated from China, India, South Korea, and USA. Climate change adversely affected different eye conditions, with ocular surface diseases (e.g., conjunctivitis and dry eye) being most affected. Moreover, higher particulate matter (PM) was the most widely assessed pollutant and was adversely associated with the majority of eye conditions, increasing the burden on patients and healthcare providers. We found a low frequency of publications related to the delivery of eye care and its impact on climate change in countries with high air pollution and climate change burden.

Association of Long-Term Exposure to Ambient Air Pollution With the Risk of Acute Primary Angle Closure

Purpose

The purpose of this study was to investigate the association between long-term exposure to ambient air pollutants and the risk of acute primary angle closure (APAC).

Methods

Two hundred eighty-one (281) patients with APAC and 730 age- and sex-matched controls hospitalized between January 2017 and December 2019 were enrolled in this retrospective case-control study. Residential exposure to ambient air pollutants, including fine particulate matter (PM2.5), inhalable particulate (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone were estimated by satellite-models or ground measurement. Multivariate regression analyses explored the association between annual air pollutants exposure and the risk of APAC.

Results

Of the 1011 participants (31.1% were male subjects), the average age was 64.0 years. Long-term exposure to PM2.5, PM10, and SO2 were significantly associated with an increased risk of APAC. The adjusted odds ratios (aORs) for each interquartile range (IQR) increment of PM2.5, PM10, and SO2 were 1.28 (95% confidence interval [CI] = 1.06-1.57), 1.26 (95% CI = 1.06-1.50), and 1.30 (95% CI = 1.04-1.62) separately, after controlling for confounders. Robust associations were observed for a longer lag 2-year exposure.

Conclusions

Long-term exposure to PM2.5, PM10, and SO2 was associated with an increased risk of APAC in a Chinese population. Our findings provide epidemiological implications on the adverse effects of air pollution on ocular diseases.

Translational Relevance

Long-term exposure to ambient air pollutants increased the risk of APAC.

Air Pollution and Chronic Eye Disease in Adults: A Scoping Review

PURPOSE

We conducted a scoping review of studies examining ambient air pollution as a risk factor for chronic eye disease influencing the lens, retina, and intraocular pressure in adults.

METHODS

Terms related to air pollution and eye disease outcomes were used to search for publications on Embase, Web of Science Core Collection, Global Health, PubMed, and the Cochrane Central Register of Controlled Trials from January 1, 2010, through April 11, 2022.

RESULTS

We identified 27 articles, focusing on the following non-mutually exclusive outcomes: cataract (n = 9), presbyopia (n = 1), retinal vein occlusion or central retinal arteriolar and venular equivalents (n = 5), intraocular pressure (IOP) (n = 3), glaucoma (n = 5), age-related macular degeneration (AMD) (n = 5), diabetic retinopathy (n = 2), and measures of retinal morphology (n = 3). Study designs included cross-sectional (n = 16), case-control (n = 4), and longitudinal (n = 7). Air pollutants were measured in 50% and 95% of the studies on lens and retina or IOP, respectively, and these exposures were assigned to geographic locations. Most research was conducted in global regions with high exposure to air pollution. Consistent associations suggested a possibly increased risk of cataract and retina-associated chronic eye disease with increasing exposure to particulate matter (PM2.5-PM10), NO2, NOx, and SO2. Associations with O3 were less consistent.

CONCLUSIONS

Accumulating research suggests air pollution may be a modifiable risk factor for chronic eye diseases of the lens and retina. The number of studies on each specific lens- or retina-related outcome is limited. Guidelines regarding the role of air pollution in chronic eye disease do not exist.

Loliolide in Sargassum horneri Alleviates Ultrafine Urban Particulate Matter (PM 0.1)-Induced Inflammation in Human RPE Cells

Owing to increasing air pollution due to industrial development, fine dust has been associated with threatening public health. In particular, ultrafine urban particulate matter (uf-UP, PM 0.1) can easily enter our bodies, causing inflammation-related diseases. Therefore, in the present study, we evaluated the effects of hydrothermal extracts of Sargassum horneri and its bioactive compound, loliolide, on uf-UP-induced inflammation as a potential treatment strategy for retinal disorders. Human retinal pigment epithelial cells (ARPE-19) stimulated with TNF-α or uf-UPs were treated with S. horneri extract and loliolide. S. horneri extracts exhibited anti-inflammatory effects on uf-UP-induced inflammation without cell toxicity through downregulating the mRNA expression of MCP-1, IL-8, IL-6, and TNF-α. UPLC-QTOF/MS analysis confirmed that the hydrothermal extract of S. horneri contained loliolide, which has anti-inflammatory effects. Loliolide effectively reduced the mRNA expression and production of proinflammatory chemokines (IL-8) and cytokines (IL-1β and IL-6) by downregulating the MAPK/NF-ĸB signaling pathway on TNF-α-stimulated inflammatory ARPE-19 cells. These effects were further confirmed in inflammatory ARPE-19 cells after stimulation with uf-UPs. Collectively, these results suggested the application of S. horneri as a functional ingredient for treating ocular disorders caused by particular matters.

The Correlation of Global Burden of Vision Impairment and Ambient Atmospheric Fine Particulate Matter

Purpose

To assess the correlation between the worldwide burden of vision impairment (VI) and fine particulate matter (PM) 2.5.

Methods

In this retrospective cross-sectional study, global and national prevalence and disability-adjusted lost year (DALY) numbers and rates of total VI, glaucoma, cataract, and age-related macular degeneration (AMD) were obtained from the Global Burden of Disease database. The global and national levels of PM2.5 levels were also extracted. The main outcome measures were the correlation of PM2.5 levels with total VI and three ocular diseases in different age, sex, and socioeconomic subgroups.

Results

In 2019, the worldwide prevalence of total VI and exposure level of PM2.5 was 9.6% (95% uncertainty interval: 8.0-11.3) and 42.5 μg/m3, respectively. The national age-standardized prevalence rates of total VI (r p = 0.52, P < 0.001), glaucoma (r p = 0.65, P < 0.001), AMD (r p = 0.67, P < 0.001), and cataract (r p = 0.44, P < 0.001) have a positive correlation with PM2.5 levels. In addition, the national age-standardized DALY rates of total VI (r p = 0.62, P < 0.001), glaucoma (r p = 0.62, P < 0.001), AMD (r p = 0.54, P < 0.001), and cataract (r p = 0.45, P < 0.001) significantly correlated with PM2.5 levels. The correlations remained significant in different age, sex, and sociodemographic subgroups.

Conclusion

National prevalence rates of VI and three major ocular diseases correlate significantly with PM2.5 exposure levels, worldwide.

Risk factors associated with elevated intraocular pressure: a population-based study in a rural community of Bangladesh

OBJECTIVE

High intraocular pressure (IOP) is one of the major modifiable risk factors for glaucoma. The objective was to examine socio-demographic and clinical factors related to IOP.

METHODS AND ANALYSIS

This study was conducted among 3097 adults residing in a rural area of Bangladesh, with all participants undergoing clinical and ophthalmological evaluations. The measurement of IOP was carried out using of a rebound Tonometer called Icare pro. Multiple logistic regression analysis was employed to identify variables associated to IOP levels of 21 mm Hg or above. Adjusted OR (aOR) and 95% CI were reported.

RESULTS

This study found that, in total, 9% of the study population had high IOP in one or both eyes. Elevated IOP was significantly associated with respondents who were service holders (aOR 2.52; 95% CI 1.48 to 4.31), had a lower education level (aOR 1.55, 95% CI 1.07 to 2.23), used biomass fuel (aOR 2.00; 95% CI 1.09 to 3.67), belonged to a higher socioeconomic position (aOR 1.55, 95% CI 1.07 to 2.23) and had obesity (aOR 2.00; 95% CI 1.07 to 3.73), hypertension (aOR 1.32; 95% CI 1.01 to 1.73) or history of diabetes (aOR 2.44; 95% CI 1.67 to 3.55), after adjusting for covariates including age, sex, marital status, light source and tobacco consumption, in a multiple regression analysis.

CONCLUSION

Chronic diseases, such as hypertension and diabetes, obesity and sociodemographic characteristics such as high socioeconomic status and use of biomass fuels, have all been linked to elevated IOP. Patients with chronic diseases should undergo for IOP testing regularly.

Emerging roles of air pollution and meteorological factors in autoimmune eye diseases

Autoimmune eye diseases (AEDs), a collection of autoimmune inflammatory ocular conditions resulting from the dysregulation of immune system at the ocular level, can target both intraocular and periorbital structures leading to severe visual deficit and blindness globally. The roles of air pollution and meteorological factors in the initiation and progression of AEDs have been increasingly attractive, among which the systemic and local mechanisms are both involved in. Exposure to excessive air pollution and extreme meteorological conditions including PM2.5/PM0.1, environmental tobacco smoke, insufficient sunshine, and high temperature, etc., can disturb Th17/Treg balance, regulate macrophage polarization, activate neutrophils, induce systemic inflammation and oxidative stress, decrease retinal blood flow, promote tissue fibrosis, activate sympathetic nervous system, adversely affect nutrients synthetization, as well as induce heat stress, therefore may together deteriorate AEDs. The crosstalk among inflammation, oxidative stress and dysregulated immune system appeared to be prominent. In the present review, we will concern and summarize the potential mechanisms underlying linkages of air pollution and meteorological factors to ocular autoimmune and inflammatory responses. Moreover, we concentrate on the specific roles of air pollutants and meteorological factors in several major AEDs including uveitis, Graves' ophthalmopathy (GO), ocular allergic disease (OAD), glaucoma, diabetic retinopathy (DR), etc.

A Review of Ambient Air Pollution as a Risk Factor for Posterior Segment Ocular Diseases

PURPOSE

To review the most recent evidence on the association of ambient air pollution with posterior segment ocular diseases.

METHODS

A search of the most recently published medical literature was performed in PubMed and Google Scholar on 10 December 2022. Articles published between 2018 and December 2022 were included in this rapid review. Studies that evaluated the association between ambient air pollutants (nitrogen dioxide (NO₂), carbon monoxide (CO), sulfur dioxide (SO₂), ozone (O₃), particulate matters (PM_s), total hydrocarbons (THC), nonmethane hydrocarbons (NMHC), benzene), and ocular posterior segment diseases (glaucoma, age-related macular degeneration (AMD), and retinal vascular diseases) were included.

RESULTS

Nineteen research articles met the inclusion criteria. Significant associations were found between PM_2.5 and glaucoma, including primary open angle, primary angle closure, and normal tension glaucoma. An increased risk of AMD was linked to increased exposure to PM_2.5, NO₂, and CO. Single studies suggested that increased exposure to PM_2.5 and PM₁₀ is associated with diabetic retinopathy; THC and NMHC increased the risk of retinal vein occlusion; and CO, NO₂, and PM₁₀ are linked to an increased risk of central retinal artery occlusion.

CONCLUSIONS

There is increasing evidence that toxic air pollutants have an impact on posterior segment ocular diseases, hence determining it as a potential modifiable risk factor for visual impairment.

Metabolomic Evaluation of Air Pollution-related Bone Damage and Potential Mediation

Ambient air pollution has been associated with bone damage. However, no studies have evaluated the metabolomic response to air pollutants and its potential influence on bone health in postmenopausal women. We analyzed data from WHI participants with plasma samples. Whole-body, total hip, femoral neck, and spine BMD at enrollment and follow-up (Y1, Y3, Y6). Daily particulate matter NO, NO2, PM10 and SO2 were averaged over 1-, 3-, and 5-year periods before metabolomic assessments. Statistical analyses included multivariable-adjusted linear mixed models, pathways analyses, and mediation modeling. NO, NO2, and SO2, but not PM10, were associated with taurine, inosine, and C38:4 phosphatidylethanolamine (PE), at all averaging periods. We found a partial mediation of C38:4 PE in the association between 1-year average NO and lumbar spine BMD (p-value: 0.032). This is the first study suggesting that a PE may partially mediate air pollution-related bone damage in postmenopausal women.

Linking Air Pollution Exposure to Blood-Based Metabolic Features in a Community-Based Aging Cohort with and without Dementia

BACKGROUND

Long-term exposure to air pollution has been associated with changes in levels of metabolites measured in the peripheral blood. However, most research has been conducted in ethnically homogenous, young or middle-aged populations.

OBJECTIVE

To study the relationship between the plasma metabolome and long-term exposure to three air pollutants: particulate matter (PM) less than 2.5μm in aerodynamic diameter (PM2.5), PM less than 10μm in aerodynamic diameter (PM10), and nitrogen dioxide (NO2) in an ethnically diverse, older population.

METHODS

Plasma metabolomic profiles of 107 participants of the Washington Heights and Inwood Community Aging Project in New York City, collected from 1995-2015, including non-Hispanic white, Caribbean Hispanic, and non-Hispanic Black older adults were used. We estimated the association between each metabolic feature and predicted annual mean exposure to the air pollutants using three approaches: 1) A metabolome wide association study framework; 2) Feature selection using elastic net regression; and 3) A multivariate approach using partial-least squares discriminant analysis.

RESULTS

79 features associated with exposure to PM2.5 but none associated with PM10 or NO2. PM2.5 exposure was associated with altered amino acid metabolism, energy production, and oxidative stress response, pathways also associated with Alzheimer's disease. Three metabolites were associated with PM2.5 exposure through all three approaches: cysteinylglycine disulfide, a diglyceride, and a dicarboxylic acid. The relationship between several features and PM2.5 exposure was modified by diet and metabolic diseases.

CONCLUSIONS

These relationships uncover the mechanisms through which PM2.5 exposure can lead to altered metabolic outcomes in an older population.

Disparities in Vision Health and Eye Care

Significant disparities in vision health and eye care exist. To achieve health equity, we must understand the root causes and drivers of health disparities and inequities, including social determinants of health and systemic racism.

Acute exposure to air pollutants increase the risk of acute glaucoma

Background

Ambient air pollution is related to the onset and progression of ocular disease. However, the effect of air pollutants on the acute glaucoma remains unclear.

Objective

To investigate the effect of air pollutants on the incidence of acute glaucoma (acute angle closure glaucoma and glaucomatocyclitic crisis) among adults.

Methods

We conducted a time-stratified case-crossover study based on the data of glaucoma outpatients from January, 2015 to Dec, 2021 in Shanghai, China. A conditional logistic regression model combined with a polynomial distributed lag model was applied for the statistical analysis. Each case serves as its own referent by comparing exposures on the day of the outpatient visit to the exposures on the other 3–4 control days on the same week, month and year. To fully capture the delayed effect of air pollution, we used a maximum lag of 7 days in main model.

Results

A total of 14,385 acute glaucoma outpatients were included in this study. We found exposure to PM_2.5, PM₁₀, nitrogen dioxide (NO₂) and carbon monoxide (CO) significantly increased the odds of outpatient visit for acute glaucoma. Wherein the odds of acute glaucoma related to PM_2.5 and NO₂ were higher and more sustained, with OR of 1.07 (95%CI: 1.03–1.11) and 1.12 (95% CI: 1.08–1.17) for an IQR increase over lag 0–3 days, than PM₁₀ and CO over lag 0–1 days (OR:1.03; 95% CI: 1.01–1.05; OR: 1.04; 95% CI: 1.01–1.07).

Conclusions

This case-crossover study provided first-hand evidence that air pollutants, especially PM_2.5 and NO₂, significantly increased risk of acute glaucoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14078-9.

Ocular and Systemic Factors Associated with Glaucoma

Glaucoma is one of the leading causes of irreversible blindness in the world. Although numerous factors have been implicated in the pathogenesis of glaucoma, the main focus of management still remains lowering the intraocular pressure (IOP) by medical or surgical therapy. However, a major challenge is that many glaucoma patients continue to progress despite good control of IOP. In this regard, the importance of other coexisting factors that may contribute to disease progression needs to be explored. Ophthalmologists need to be aware of ocular risk factors and the impact of systemic diseases and their medications, along with lifestyle modifications on the course of glaucomatous optic neuropathy and adopt a holistic approach in treating the eye as well as the patient to alleviate the suffering from glaucoma in a comprehensive manner.

How to cite this article

Dada T, Verma S, Gagrani M, et al. Ocular and Systemic Factors associated with Glaucoma. J Curr Glaucoma Pract 2022;16(3):179-191.

Fine Particulate Matter Exposure Levels in Patients with Normal-Tension Glaucoma and Primary Open-Angle Glaucoma: A Population-Based Study from Taiwan

Patients with NTG or POAG with more than one outpatient or discharge diagnosis from the ophthalmology department were included in the study. These data were merged with the PM2.5 data from the Air Quality Monitoring Network for analysis. This was a case−control study, with 1006 participants in the NTG group and 2533 in the POAG group. To investigate fine particulate matter (PM2.5) exposure levels in patients with normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG), patient data were obtained from Taiwan’s Longitudinal Health Insurance Database 2000 for the 2008 to 2013 period. We used a multivariate logic regression model to assess the risk for each participant. The PM2.5 exposure levels were divided into four groups: <25th percentile (Q1), <617 μg/mm3; 25th to 50th percentile (Q2), 617 to 1297 μg/mm3; 50th to 75th percentile (Q3), 1297 to 2113 μg/mm3; and >75th percentile (Q4), >2113 μg/mm3. The results are expressed in terms of odds ratio (OR) and 95% CI. A multiple logistic regression was used to compare the results of the NTG group with those of the POAG group. Compared with the PM2.5 Q1 level, the OR of the PM2.5 Q2 level was 1.009 (95% CI 0.812−1.254), the PM2.5 Q3 level was 1.241 (95% CI 1.241−1.537, p < 0.05), and the PM2.5 Q4 level was 1.246 (95% CI 1.008−1.539, p < 0.05). Our research reveals that compared with POAG, the risk of developing NTG is more closely related with PM2.5 exposure, and PM2.5 has a concentration−dose effect. It is hoped that in the future, in the clinical judgment of NTG and POAG, the level of PM2.5 in the environment can be taken as a risk factor.

Effect of NLRP3 repression on NLRP3 inflammasome activation in human corneal epithelial cells with black carbon exposure

PURPOSE

To investigate the inhibitory effects of NLRP3 siRNA on NLRP3 inflammasome activation in human corneal epithelial cells (HCECs) with fresh black carbon (FBC) particles and ozone-oxidized BC (OBC) particles treatment.

METHODS

HCECs were transfected with NLRP3 siRNA or control siRNA for 48 h, followed by 200 μg/ml FBC or OBC suspension for an additional 72 h. Untreated controls were cells with no siRNA transfection or BC treatment. RT-qPCR and Western blot were used to measure mRNA and protein levels of components of the NLRP3 inflammasome (NLRP3, ASC, and Caspase-1) and downstream cytokine (IL-1β), respectively.

RESULTS

Compared with untreated control cells, mRNA levels of NLRP3, ASC, Caspase-1, and IL-1β were significantly higher (p < 0.05) in control siRNA transfected cells with BC treatments. Compared with the control siRNA transfected cells, NLRP3 siRNA transfection reduced the expression of NLRP3 and ASC, whereas it had a limited effect on the expression of Caspase-1 and IL-1β with FBC or OBC exposures. Under FBC treatment, the reductions of NLRP3 and Caspase-1 mRNA levels were 53.5% (p < 0.001) and 34.2% (p < 0. 01), respectively, and NLRP3 and ASC protein levels were lowered by 58.2% (p < 0.001) and 45.4% (p < 0.001), respectively. Under OBC treatment, the reductions of NLRP3 and Caspase-1 mRNA levels were 39.8% (p < 0.001) and 25.6% (p < 0.05), respectively, and NLRP3 and ASC protein levels were lowered by 44.8% (p < 0.001) and 41.7% (p < 0.001), respectively. Moreover, mRNA levels of ASC and IL-1β, the protein levels of Caspase-1 and IL-1β showed a tendency to decrease in NLRP3 siRNA transfected cells, it was statistically insignificant (p > 0.05).

CONCLUSIONS

NLRP3 siRNA transfection could partially reverse the increased mRNA levels of NLRP3 and Caspase-1, the protein levels of NLRP3 and ASC in HCECs with BC treatment, whereas the reductions of protein levels of Caspase-1 and IL-1β were not significant, indicating that NLRP3 siRNA has a limited inhibitory effect on the activation of NLRP3 inflammasome triggered by BC.

Short-Term Cumulative Exposure to Ambient Traffic-Related Black Carbon and Blood Pressure: MMDA Traffic Enforcers' Health Study

Exposure to traffic-related air pollution is linked with acute alterations in blood pressure (BP). We examined the cumulative short-term effect of black carbon (BC) exposure on systolic (SBP) and diastolic (DBP) BP and assessed effect modification by participant characteristics. SBP and DBP were repeatedly measured on 152 traffic enforcers. Using a linear mixed-effects model with random intercepts, quadratic (QCDL) and cubic (CCDL) constrained distributed lag models were fitted to estimate the cumulative effect of BC concentration on SBP and DBP during the 10 hours (daily exposure) and 7 days (weekly exposure) before the BP measurement. Ambient BC was related to increased BP with QCDL models. An interquartile range change in BC cumulative during the 7 days before the BP measurement was associated with increased BP (1.2% change in mean SBP, 95% confidence interval (CI), 0.1 to 2.3; and 0.5% change in mean DBP, 95% CI, −0.8 to 1.7). Moreover, the association between the 10-h cumulative BC exposure and SBP was stronger for female (4.0% change, 95% CI: 2.1–5.9) versus male and for obese (2.9% change, 95% CI: 1.0–4.8) vs. non-obese traffic enforcers. Short-term cumulative exposure to ambient traffic-related BC could bring about cardiovascular diseases through mechanisms involving increased BP.

Lifetime exposure of ambient PM2.5 elevates intraocular pressure in young mice

Epidemiological studies suggest that ambient particulate matter exposure may be a new risk factor of glaucoma, but it lacks solid experimental evidence to establish a causal relationship. In this study, young mice (4 weeks old) were exposed concentrated ambient PM2.5 (CAP) for 9 months, which is throughout most of the life span of a mouse under heavy pollution. CAP was introduced using a versatile aerosol concentration enrichment system which mimics natural PM2.5 exposure. CAP exposure caused a gradual elevation of intraocular pressure (IOP) and an increase in aqueous humor outflow resistance. In the conventional outflow tissues that regulates IOP, inducible nitric oxide synthase (iNOS) was up-regulated and 3-nitrotyrosine (3-NT) formation increased. At the cellular level, PM2.5 exposure increased the transendothelial electrical resistance of cells that control IOP (AAP cells). This is accompanied by increased reactive oxygen species (ROS), iNOS and 3-NT levels. Peroxynitrite scavenger MnTMPyP successfully treated the IOP elevation and restored it to normal levels by reducing 3-NT formation in outflow tissues. This study provides the novel evidence that in young mice, lifetime whole-body PM2.5 exposure has a direct toxic effect on intraocular tissues, which imposes a significant risk of IOP elevation and may initiate the development of ocular hypertension and glaucoma. This occurs as a result of protein nitration of conventional aqueous humor outflow tissues.

Comparison of Medical Comorbidity between Patients with Normal-Tension Glaucoma and Primary Open-Angle Glaucoma: A Population-Based Study in Taiwan

The objective was to investigate different comorbidities developed in normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG) patients. This was a case-control study, with 1489 people in the NTG group and 5120 people in the POAG group. Patient data were obtained from the Longitudinal Health Insurance Database 2010 (LHID2010) of Taiwan for the 2008-2013 period. The chi-square test was used to compare categorical variables, such as gender, income and urbanisation level, between NTG and POAG patients, and the two-tailed t test was used to compare continuity between the two groups. We use a multivariate logic regression model to assess the risk of each participant. The results are expressed in terms of odds ratio (OR) and 95% confidence intervals (CI). Patients with NTG had significantly higher proportions of hypotension (adjusted OR, 1.984; 95% CI, 1.128-3.490), sleep disturbances (adjusted OR, 1.323; 95% CI, 1.146-1.528), peptic ulcers (adjusted OR, 1.383; 95% CI, 1.188-1.609) and allergic rhinitis (adjusted OR, 1.484; 95% CI, 1.290-1.707) than those with POAG. Conversely, arterial hypertension (adjusted OR, 0.767; 95% CI, 0.660-0.893), diabetes (adjusted OR, 0.850; 95% CI, 0.728-0.993) and atopic dermatitis (adjusted OR, 0.869; 95% CI, 0.763-0.990) had a lower risk in the NTG group than in the POAG group. We found that comorbidities such a hypotension, sleep disturbances and peptic ulcer and allergic rhinitis are more highly associated to NTG than POAG.

Fine Particulate Matter and Age-Related Eye Disease: The Canadian Longitudinal Study on Aging

Purpose

To determine the relationship between fine particulate matter (PM2.5) and ocular outcomes such as visual impairment and age-related eye disease.

Methods

Baseline data were used from the Canadian Longitudinal Study on Aging. The Comprehensive Cohort consisted of 30,097 adults ages 45 to 85 years. Annual mean PM2.5 levels (µg/m3) for each participant's postal code were estimated from satellite data. Ozone, sulfur dioxide, and nitrogen dioxide levels were also estimated. Binocular presenting visual acuity was measured using a visual acuity chart. Intraocular pressure (IOP) was measured in millimeters of mercury using the Reichart Ocular Response Analyzer. Participants were asked about a diagnosis of glaucoma, macular degeneration, or cataract. Logistic and linear regression models were used.

Results

The overall mean PM2.5 level was 6.5 µg/m3 (SD = 1.8). In the single pollutant models, increased PM2.5 levels (per interquartile range) were associated with visual impairment (odds ratio [OR] = 1.12; 95% confidence interval [CI], 1.02-1.24), glaucoma (OR = 1.14; 95% CI, 1.01-1.29), and visually impairing age-related macular degeneration (OR = 1.52; 95% CI, 1.10-2.09) after adjustment for sociodemographics and disease. PM2.5 had a borderline adjusted association with cataract (OR = 1.06; 95% CI, 0.99-1.14). In the multi-pollutant models, increased PM2.5 was associated with glaucoma and IOP only after adjustment for sociodemographics and disease (OR = 1.24; 95% CI, 1.05-1.46 and β = 0.24; 95% CI, 0.12-0.37).

Conclusions

Increased PM2.5 is associated with glaucoma and IOP. These associations should be confirmed using longitudinal data and potential mechanisms should be explored. If confirmed, this work may have relevance for revision of World Health Organization thresholds to protect human health.

Ambient PM2.5 species and ultrafine particle exposure and their differential metabolomic signatures

BACKGROUND

The metabolomic signatures of short- and long-term exposure to PM_2.5 have been reported and linked to inflammation and oxidative stress. However, little is known about the relative contribution of the specific PM_2.5 species (hence sources) that drive these metabolomic signatures.

OBJECTIVES

We aimed to determine the relative contribution of the different species of PM_2.5 exposure to the perturbed metabolic pathways related to changes in the plasma metabolome.

METHODS

We performed mass-spectrometry based metabolomic profiling of plasma samples among men from the Normative Aging Study to identify metabolic pathways associated with PM_2.5 species. The exposure windows included short-term (one, seven-, and thirty-day moving average) and long-term (one year moving average). We used linear mixed-effect regression with subject-specific intercepts while simultaneously adjusting for PM_2.5, NO₂, O₃, temperature, relative humidity, and covariates and correcting for multiple testing. We also used independent component analysis (ICA) to examine the relative contribution of patterns of PM_2.5 species.

RESULTS

Between 2000 and 2016, 456 men provided 648 blood samples, in which 1158 metabolites were quantified. We chose 305 metabolites for the short-term and 288 metabolites for the long-term exposure in this analysis that were significantly associated (p-value < 0.01) with PM_2.5 to include in our PM_2.5 species analysis. On average, men were 75.0 years old and their body mass index was 27.7 kg/m². Only 3% were current smokers. In the adjusted models, ultrafine particles (UFPs) were the most significant species of short-term PM_2.5 exposure followed by nickel, vanadium, potassium, silicon, and aluminum. Black carbon, vanadium, zinc, nickel, iron, copper, and selenium were the significant species of long-term PM_2.5 exposure. We identified several metabolic pathways perturbed with PM_2.5 species including glycerophospholipid, sphingolipid, and glutathione. These pathways are involved in inflammation, oxidative stress, immunity, and nucleic acid damage and repair. Results were overlapped with the ICA.

CONCLUSIONS

We identified several significant perturbed plasma metabolites and metabolic pathways associated with exposure to PM_2.5 species. These species are associated with traffic, fuel oil, and wood smoke. This is the largest study to report a metabolomic signature of PM_2.5 species' exposure and the first to use ICA.

Exposure to ambient air pollution and visual impairment in children: A nationwide cross-sectional study in China

Evidence concerning exposure to air pollution and visual impairment is scarce. We evaluated the associations of ambient air pollution with visual impairment and visual acuity levels in Chinese schoolchildren. We recruited 61,995 children from 7 provinces/municipalities across China. Concentrations of air pollutants (i.e., particulate matter with an aerodynamic diameter of ≤ 1.0 µm [PM₁], ≤ 2.5 µm [PM_2.5], and 10 µm [PM₁₀] as well as nitrogen dioxides [NO₂]) were measured using machine learning methods. Visual acuity levels were measured using standard protocols. We used SAS PROC SURVEYLOGISTIC to assess the association between air pollution and visual impairment. An interquartile range increase in PM₁, PM_2.5, PM₁₀, and NO₂ was associated with a 1.133- (95% CI, 1.035-1.240), 1.267- (95% CI, 1.082-1.484), 1.142- (95% CI, 1.019-1.281), and 1.276-fold (95% CI, 1.173-1.388) increased odds of visual impairment, and the associations were stronger in children being boys, older, living in rural areas, and born to parents who had a lower educational level or smoked, compared to their counterparts. These results suggest that exposure to air pollution were positively associated with the odds of visual impairment, and the association may be modified by children's age, sex, and residential area as well as parental education level and cigarette smoking.

Airborne particulate matter (PM2.5) triggers ocular hypertension and glaucoma through pyroptosis

Background

Particulate matter (PM) is strongly linked to human health and has detrimental effects on the eye. Studies have, however, focused on the ocular surface, with limited research on the impact of PM_2.5 on intraocular pressure (IOP).

Methods

To investigate the impact of PM_2.5 on IOP and the associated mechanism, C57BL/6 mouse eyes were topically exposed to a PM_2.5 suspension for 3 months, and human trabecular meshwork (HTM) cells were subjected to various PM_2.5 concentrations in vitro. Cell viability, NLRP3/caspase-1, IL-1β, and GSDMD expression, reactive oxygen species (ROS) production and cell contractility were measured by western blot, ELISA, cell counting kit-8, ROS assay kit or a cell contractility assay. ROS scavenger N-acetyl-L-cysteine (NAC) and caspase-1 inhibitor VX-765 were used to intervene in PM_2.5-induced damages.

Results

The results revealed that the IOP increased gradually after PM_2.5 exposure, and upregulations of the NLRP3 inflammasome, caspase-1, IL-1β, and GSDMD protein levels were observed in outflow tissues. PM_2.5 exposure decreased HTM cell viability and affected contraction. Furthermore, elevated ROS levels were observed as well as an activation of the NLRP3 inflammasome and downstream inflammatory factors caspase-1 and IL-1β. NAC improved HTM cell viability, inhibited the activation of the NLRP3 inflammasome axis, and HTM cell contraction by scavenging ROS. VX-765 showed similar protection against the PM_2.5 induced adverse effects.

Conclusion

This study provides novel evidence that PM_2.5 has a direct toxic effect on intraocular tissues and may contribute to the initiation and development of ocular hypertension and glaucoma. This occurs as a result of increased oxidative stress and the subsequent induction of NLRP3 inflammasome mediated pyroptosis in trabecular meshwork cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-021-00403-4.

Association Between PM2.5 Exposure Level and Primary Open-Angle Glaucoma in Taiwanese Adults: A Nested Case-Control Study

Primary open-angle glaucoma (POAG) is the most common type of glaucoma. However, little is known about POAG in adults and exposure to air pollution. The current study aims to investigate whether exposure to particulate matter with a mass median aerodynamic diameter of ≤2.5 μm (PM2.5) is associated with POAG diagnosis. Patient data were obtained from the Longitudinal Health Insurance Database 2010 (LHID2010) of Taiwan for the 2008-2013 period. PM2.5 concentration data, collected from the Ambient Air Quality Monitoring Network established by the Environmental Protection Administration of Taiwan, were categorized into four groups according to World Health Organization (WHO) exposure standards for PM2.5. We estimated the odds ratios (ORs) and 95% CIs for risk factors for POAG with logistic regression. The OR of per WHO standard level increase was 1.193 (95% CI 1.050-1.356). Compared with the normal level, the OR of WHO 2.0 level was 1.668 (95% CI 1.045-2.663, P < 0.05). After excluding confounding risk factors for POAG in this study, we determined that increased PM2.5 exposure is related to POAG risk (ORs > 1, P < 0.05). In this study, PM2.5 was an independent factor associated with open-angle glaucoma. Further research is required to better understand the mechanisms connecting PM2.5 and open-angle glaucoma.

Association of ambient air pollution with age-related macular degeneration and retinal thickness in UK Biobank

AIM

To examine the associations of air pollution with both self-reported age-related macular degeneration (AMD), and in vivo measures of retinal sublayer thicknesses.

METHODS

We included 115 954 UK Biobank participants aged 40-69 years old in this cross-sectional study. Ambient air pollution measures included particulate matter, nitrogen dioxide (NO₂) and nitrogen oxides (NO_x). Participants with self-reported ocular conditions, high refractive error (< -6 or > +6 diopters) and poor spectral-domain optical coherence tomography (SD-OCT) image were excluded. Self-reported AMD was used to identify overt disease. SD-OCT imaging derived photoreceptor sublayer thickness and retinal pigment epithelium (RPE) layer thickness were used as structural biomarkers of AMD for 52 602 participants. We examined the associations of ambient air pollution with self-reported AMD and both photoreceptor sublayers and RPE layer thicknesses.

RESULTS

After adjusting for covariates, people who were exposed to higher fine ambient particulate matter with an aerodynamic diameter <2.5 µm (PM_2.5, per IQR increase) had higher odds of self-reported AMD (OR=1.08, p=0.036), thinner photoreceptor synaptic region (β=-0.16 µm, p=2.0 × 10^-5), thicker photoreceptor inner segment layer (β=0.04 µm, p=0.001) and thinner RPE (β=-0.13 µm, p=0.002). Higher levels of PM_2.5 absorbance and NO₂ were associated with thicker photoreceptor inner and outer segment layers, and a thinner RPE layer. Higher levels of PM₁₀ (PM with an aerodynamic diameter <10 µm) was associated with thicker photoreceptor outer segment and thinner RPE, while higher exposure to NO_x was associated with thinner photoreceptor synaptic region.

CONCLUSION

Greater exposure to PM_2.5 was associated with self-reported AMD, while PM_2.5, PM_2.5 absorbance, PM₁₀, NO₂ and NO_x were all associated with differences in retinal layer thickness.

Metabolomic signatures of the long-term exposure to air pollution and temperature

BACKGROUND

Long-term exposures to air pollution has been reported to be associated with inflammation and oxidative stress. However, the underlying metabolic mechanisms remain poorly understood.

OBJECTIVES

We aimed to determine the changes in the blood metabolome and thus the metabolic pathways associated with long-term exposure to outdoor air pollution and ambient temperature.

METHODS

We quantified metabolites using mass-spectrometry based global untargeted metabolomic profiling of plasma samples among men from the Normative Aging Study (NAS). We estimated the association between long-term exposure to PM2.5, NO2, O3, and temperature (annual average of central site monitors) with metabolites and their associated metabolic pathways. We used multivariable linear mixed-effect regression models (LMEM) while simultaneously adjusting for the four exposures and potential confounding and correcting for multiple testing. As a reduction method for the intercorrelated metabolites (outcome), we further used an independent component analysis (ICA) and conducted LMEM with the same exposures.

RESULTS

Men (N = 456) provided 648 blood samples between 2000 and 2016 in which 1158 metabolites were quantified. On average, men were 75.0 years and had an average body mass index of 27.7 kg/m2. Almost all men (97%) were not current smokers. The adjusted analysis showed statistically significant associations with several metabolites (58 metabolites with PM2.5, 15 metabolites with NO2, and 6 metabolites with temperature) while no metabolites were associated with O3. One out of five ICA factors (factor 2) was significantly associated with PM2.5. We identified eight perturbed metabolic pathways with long-term exposure to PM2.5 and temperature: glycerophospholipid, sphingolipid, glutathione, beta-alanine, propanoate, and purine metabolism, biosynthesis of unsaturated fatty acids, and taurine and hypotaurine metabolism. These pathways are related to inflammation, oxidative stress, immunity, and nucleic acid damage and repair.

CONCLUSIONS

Using a global untargeted metabolomic approach, we identified several significant metabolites and metabolic pathways associated with long-term exposure to PM2.5, NO2 and temperature. This study is the largest metabolomics study of long-term air pollution, to date, the first study to report a metabolomic signature of long-term temperature exposure, and the first to use ICA in the analysis of both.

Long-Term Exposure to Urban Particulate Matter on the Ocular Surface and the Incidence of Deleterious Changes in the Cornea, Conjunctiva and Retina in Rats

We investigated the time-dependent deleterious ocular changes induced by urban particulate matter (UPM) in vitro and in vivo. UPM treatment decreased human corneal epithelial cell migration and survival. Fluorescein scores were consistently increased by UPM application for 16 weeks. One week of rest at 2 or 4 weeks led to a recovery trend, whereas two weeks of rest at 8 weeks induced no change. UPM treatment decreased the tear film break-up time at 2 weeks, which was thereafter maintained until 16 weeks. No changes were found after periods of rest. UPM-treated eyes exhibited greater corneal epithelium thickness than normal eyes at 2 weeks, which recovered to normal at 4 and 8 weeks and was significantly decreased at 16 weeks. Apoptotic cell number in the epithelium was increased at 2 weeks, which remained constant except at 8 weeks. IL-6 expression in the cornea of the right eye continually increased for 16 weeks, and significant recovery was only observed at 8 weeks after 2 weeks of rest. Ocular pressure was significantly increased in the right eye at 12 and 16 weeks. Topical UPM application to the eye induced deleterious changes to various closely related parts of the eye.

Association of Ambient Particulate Matter Exposure with the Incidence of Glaucoma in Childhood

PURPOSE

We investigated whether exposure to air pollution, particularly to particles with a mass median aerodynamic diameter of ≤10 μm (PM₁₀), is associated with diagnosis of childhood glaucoma.

DESIGN

Retrospective cohort study.

METHODS

From the National Health Insurance Service-National Sample Cohort, a total of 9004 infants born between January 2002 and December 2002 were included and followed-up for an 11-year period (2003-2012). Patients with glaucoma were defined as International Classification of Diseases, 10th revision code H40. Exposure levels of PM₁₀ were extrapolated using geographic information systems, and individual exposure levels were assigned.

RESULTS

During the study period, glaucoma occurred in 85 patients (0.94%). The probability of developing childhood glaucoma increased with the increase in PM₁₀ quartiles. Increases in 1 μg/m³ of long-term PM₁₀ were significantly associated with increased hazard ratios (HRs) for childhood glaucoma (HR = 1.22 [95% confidence interval {CI} 1.15-1.28]). Compared with risk of the lowest PM₁₀ exposure group (quartile 1), the adjusted HRs for childhood glaucoma were significant in the highest PM₁₀ exposure group of quartile 4 (HR = 2.84 [95% CI 1.37-5.89]) in model 3. Regarding the long-term PM₁₀ exposure, the estimated hazard was considerably elevated in quartile 4 (HR = 6.61 [95% CI 2.96-14.75]).

CONCLUSIONS

Short-term and long-term exposure to PM₁₀ was associated with the incidence of childhood glaucoma. This finding confirms previous reports on the link between air pollution and ocular disease and suggests that PM₁₀ exposure may be a risk for childhood glaucoma.

The Relationship Between Ambient Atmospheric Fine Particulate Matter (PM2.5) and Glaucoma in a Large Community Cohort

Purpose

Glaucoma is more common in urban populations than in others. Ninety percent of the world's population are exposed to air pollution above World Health Organization (WHO) recommended limits. Few studies have examined the association between air pollution and glaucoma.

Methods

Questionnaire data, ophthalmic measures, and ambient residential area air quality data for 111,370 UK Biobank participants were analyzed. Particulate matter with an aerodynamic diameter < 2.5 μm (PM2.5) was selected as the air quality exposure of interest. Eye measures included self-reported glaucoma, intraocular pressure (IOP), and average thickness of macular ganglion cell-inner plexiform layer (GCIPL) across nine Early Treatment Diabetic Retinopathy Study (ETDRS) retinal subfields as obtained from spectral-domain optical coherence tomography. We examined the associations of PM2.5 concentration with self-reported glaucoma, IOP, and GCIPL.

Results

Participants resident in areas with higher PM2.5 concentration were more likely to report a diagnosis of glaucoma (odds ratio = 1.06, 95% confidence interval [CI] = 1.01-1.12, per interquartile range [IQR] increase P = 0.02). Higher PM2.5 concentration was also associated with thinner GCIPL (β = -0.56 μm, 95% CI = -0.63 to -0.49, per IQR increase, P = 1.2 × 10-53). A dose-response relationship was observed between higher levels of PM2.5 and thinner GCIPL (P < 0.001). There was no clinically relevant relationship between PM2.5 concentration and IOP.

Conclusions

Greater exposure to PM2.5 is associated with both self-reported glaucoma and adverse structural characteristics of the disease. The absence of an association between PM2.5 and IOP suggests the relationship may occur through a non-pressure-dependent mechanism, possibly neurotoxic and/or vascular effects.

Association of the Robert Wood Johnson Foundations' Social Determinants of Health and Medicare Ocular Hospitalizations: A Cross Sectional Data Analysis

INTRODUCTION

Social determinants of health (SDH) may influence inpatient utilization rates and outcomes but have yet to be associated with ocular diagnoses. The purpose of this paper was to determine whether the SDH are associated with ocular hospitalizations.

METHODS

Patients from the national Medicare 100% Inpatient Limited Dataset were examined and linked to SDH measures from the Robert Wood Johnson Foundation (RWJF) County Health Rankings. Patients were included in the study group with either an admitting or primary diagnosis of an ophthalmic condition. All other hospitalized Medicare patients served in the comparison group. Nested logistic regression of these Medicare patients was conducted in their respective communities at the county level. SDH measures were benchmarked above or below the national median.

RESULTS

Positively associated SDH factors included communities with air pollution exceeding 11.62 micro grams per cubic meter (OR 1.05; 95% CI 1.01-1.08), communities where severe housing problems exceeding 14.38% (OR 1.13; 95% CI 1.09-1.18), children in single parent households exceeding 32.13% (OR 1.06; 95% CI 1.02-1.11), violent crime rate exceeding 250.54 per 100,000 (OR 1.07; 95% CI 1.03-1.12), diabetes exceeding 10.95% (OR 1.09: 95% CI 1.04-1.14), and drug poisoning deaths including opioids exceeding 14.17 per 100,000 (OR 1.04; 95% CI 1.01-1.08).

CONCLUSION

When compared to an all-condition, hospitalized population, ocular hospitalizations tended to have small, yet statistically significant associations with health behaviors, socioeconomic, and physical environment factors. Further research will be needed on how the physical environment, social, and community variables affect ocular health relative to all-cause hospitalizations.

Cytocompatible cerium oxide-mediated antioxidative stress in inhibiting ocular inflammation-associated corneal neovascularization

As oxidative stress is involved with inflammation and neovascularization, blocking oxidative stress may be beneficial for reducing inflammation. To investigate the potential use of cerium oxide nanoparticles (CeNPs) in treating neovascularization-related ophthalmic diseases, various CeNP samples were synthesized, and the sample with the best antioxidant efficacy was used in a rat model of inflammation-associated corneal neovascularization. This synthesized cerium oxide showed good biocompatibility and was capable of mediating a decrease in the expression levels of inflammatory factors via antioxidative stress. Additionally, in vitro tests showed that the Ce³⁺/Ce⁴⁺ ratio of the CeNPs directly affected the antioxidative activity, with higher ratios achieving better efficacy. The anti-inflammatory efficacy of the functional CeNPs was examined both in vitro and in vivo. Slit-lamp biomicroscopy and histological analysis revealed the gradual development of corneal neovascularization, suggesting that inflammation and neovascularization could be controlled by reducing the level of oxidative stress. CeNP-induced antioxidation could serve as a new strategy in the development of long-acting functional agents for treating ophthalmic diseases.

Ambient fine particulate matter and ozone higher than certain thresholds associated with myopia in the elderly aged 50 years and above

Although myopia has been largely ignored among the elderly population, there is an increased risk of myopia with advancing age. Ambient air pollution is one potential contributor to vision impairments, but few epidemiological studies have demonstrated such an association. This cross-sectional survey collected the information of 33,626 subjects aged ≥50 years in six developing countries during 2007-2010. Myopia was identified based on questions related to symptoms of myopia. The annual concentrations of fine particulate matter (PM_2.5) and ozone (O₃) were estimated with the satellite data and chemical transport model. We examined the associations between the two pollutants and myopia using mixed-effect Poisson regression models with robust variance estimation (sandwich estimation). We observed J-shaped associations between the two pollutants and myopia, and identified 12 and 54 μg/m³ as the threshold concentrations. The adjusted prevalence ratio was 1.12 (95% CI: 1.05, 1.21) and 1.26 (95% CI: 1.14, 1.38) for each standard deviation (SD) increase in PM_2.5 and O₃ concentrations above their threshold, respectively. In addition, the interaction analysis suggested a synergistic interaction of these two pollutants on myopia in the additive model, with a synergistic index of 1.81 (Bootstrapping 95% CI: 0.92, 4.94). Our results indicate that long-term exposures to PM_2.5 and O₃ might be important environmental risk factors of myopia in the elderly, and suggest that more efforts should be taken to reduce airborne PM_2.5 and O₃ levels to protect vision health.