A Potential Link Between Ambient Air Pollution and Intraocular Pressure

The carbon footprint and wastage of intravitreal injections

PURPOSE

The healthcare system emits greenhouse gas emissions and produces waste that in turn threatens the health of populations. The objective of our study was to measure the ecological threat related to intravitreal injections.

METHODS

Emissions were separated into scope 2 corresponding to Heating, Ventilation and Air Conditioning (HVAC) of the building, and scope 3 corresponding to travels (patients and staff), and life cycle assessment (LCA) of medical devices (MD) and pharmaceutics. Greenhouse gas (GHG) emissions and waste for a single injection were first measured through a waste audit, and secondly anticipated theoretically with a calculator.

RESULTS

The average GHG emissions and waste measured were 277kgCO2eq/IVI and 0.5kg/IVI, respectively. Pharmaceuticals were responsible for 97% of total emissions. Emissions unrelated to pharmaceuticals counted for 8.4kgCO2eq/IVI. GHG emissions and waste estimated with the calculator were 276kgCO2eq/IVI and 0.5kg/IVI, respectively, showing that the calculator was accurate.

CONCLUSION

Our study provides a puzzle piece to carbon footprint and waste assessment in the field of ophthalmology. It may help provide concrete data for future green vs. vision discussions.

Expression profiles of long noncoding RNAs in human corneal epithelial cells exposed to fine particulate matter

PURPOSE

The aim of this study was to investigate the expression profiles of long noncoding RNAs (lncRNAs) in human corneal epithelial cells (HCECs) exposed to fine particulate matter (PM_2.5) and to identify potential biological pathways involved in PM_2.5-induced toxicity in HCECs.

METHODS

Using RNA sequencing (RNA-seq) and hierarchy clustering analysis, lncRNA expression profiles in PM_2.5-treated and untreated HCECs were examined. Gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to predict the role of altered lncRNAs in biological processes and pathways. A quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay was conducted to verify the RNA-seq results in HCECs and human corneal epithelial cell sheets.

RESULTS

In total, 65 lncRNAs were altered in the PM_2.5-treated HCECs, including 41 upregulated and 24 downregulated lncRNAs. The results of the qRT-PCR assay were consistent with those of the RNA-seq analysis. The expression of two significantly upregulated lncRNAs was confirmed in human corneal epithelial cell sheets. The GO analysis demonstrated that altered lncRNAs in the PM_2.5-treated HCECs were significantly enriched in three domains: cellular component, molecular function, and biological process. The KEGG pathway analysis revealed enriched pathways of lncRNA co-expressed mRNAs, including cancer, RNA transport, and Rap1 signaling.

CONCLUSIONS

Our results suggest that lncRNAs are involved in the pathogenesis of PM_2.5-induced ocular diseases, exerting their effects through biological processes and pathogenic pathways. Among the altered lncRNAs, RP3-406P24.3 and RP11-285E9.5 may play significant roles in PM_2.5-induced ocular surface injury.

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.