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

Abstract

IMPORTANCE Elevated intraocular pressure is a major risk factor for glaucoma, a leading cause of irreversible blindness worldwide. Environmental air pollution has been suggested as a potential contributor to elevated intraocular pressure; however, no studies have demonstrated such an association to date. OBJECTIVE To investigate the association of long-term ambient black carbon exposure with intraocular pressure in community-dwelling older adults. DESIGN, SETTING, AND PARTICIPANTS This population-based analysis, conducted from October 18, 2017, through March 22, 2018, used data from the all-male, New England-based Normative Aging Study of the US Department of Veterans Affairs. The analysis included 419 older men with a total of 911 follow-up study visits between January 1, 2000, and December 30, 2011. Intraocular pressure was measured by Goldmann applanation tonometry during the study visits. Validated spatiotemporal models were used to generate 1-year black carbon exposure levels at the addresses of the participants. MAIN OUTCOMES AND MEASURES An independently developed genetic score approach was used to calculate allelic risk scores for 3 pathways associated with black carbon toxicity: endothelial function, oxidative stress, and metal processing. The associations among black carbon exposure, allelic risk scores, and intraocular pressure were explored using linear mixed-effects models. RESULTS All 419 participants were men with a mean (SD) age of 75.3 (6.9) years. The mean (SD) 1-year black carbon exposure was 0.51 (0.18) μg/m 3 , and the mean (SD) intraocular pressure for the left eye was 14.1 (2.8) mm Hg and for the right eye was 14.1 (3.0) mm Hg. Of the 911 visits, 520 (57.1%) had a high endothelial function allelic risk score, 644 (70.7%) had a high metal-processing allelic risk score, and 623 (68.4%) had a high oxidative stress allelic risk score. In fully adjusted linear mixed-effects models, the association of black carbon with intraocular pressure was greater in individuals with a high oxidative stress allelic score (β = 0.36; 95% CI, 0.003-0.73) compared with individuals with a low score (β = −0.35; 95% CI, −0.86 to 0.15). CONCLUSIONS AND RELEVANCE Ambient black carbon exposure may be a risk factor for increased intraocular pressure in individuals susceptible to other biological oxidative stressors. If additional studies confirm these results, monitoring ambient black carbon exposure and physiological oxidative stress may prevent the development and progression of intraocular pressure-related disease.

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

“…We suggest that this is a meaningful association based on our finding that inner retinal changes, as seen in glaucoma, are greater in those exposed to higher levels of PM 2.5 . Consistent with a previous report, 28,29 we found a subtle relationship between higher IOP and greater ambient PM 2.5 , although the effect was too small to explain the higher risk of glaucoma associated with PM 2.5 exposure. On the basis that a 1 mm Hg change in IOP alters the risk of glaucoma by 10%, 30 we would expect changes in IOP 10-fold higher than those observed, if the glaucoma risk was solely mediated by raised IOP.…”

“…44 The New England-based Normative Aging Study identified an association between black carbon exposure with IOP that was greater in individuals with a high oxidative stress allelic score. 29 The light absorbance of PM 2.5 filter samples has been used as a proxy measure for black carbon. 45 Oxidative stress may lead to impairment of secretion of vasoregulatory factors from endothelial cells, namely nitric oxide (NO) and endothelin-1 (ET-1), affecting ocular vascular smooth muscle tone or endothelial dysfunction, and reducing ocular blood flow.…”

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

“…A few recent studies have suggested that PM2.5 is associated with self-reported glaucoma and retinal ganglion cell and inner plexiform layer (GCIPL) thickness without IOP changes [19] and that long-term exposure to ambient black carbon increases IOP via oxidative stress [38]. In our data, an increase in ocular pressure was also detected at 8 weeks, and it consistently increased until 16 weeks (Table 1).…”

The benefits of trees for livable and sustainable communities

“…is linked to bronchitic symptoms, intraocular pressure (leads to glaucoma), myocardial infarction (i.e. heart attacks), changes in autonomic and micro-vascular function, autism, blood pressure, cognitive development problems in children (slower processing speeds, behavioral problems, attention deficit/hyperactivity disorder symptoms), blood mitochondrial abundance, heart failure, and mortality in humans (Berhane et al, 2016;Di et al, 2017;Hoek et al, 2013;Mustafić et al, 2012;Nwanaji-Enwerem et al, 2019;Peterson et al, 2015;Shah et al, 2013;Volk, Lurmann, Penfold, Hertz-Picciotto, & McConnell, 2013;Weichenthal, Hatzopoulou, & Goldberg, 2014;Zhong et al, 2016). Trees remove a tremendous amount of air pollution.…”