In the JournalsPerspective

Vehicle pollution may increase AMD risk

High rates of exposure to traffic-related air pollution may increase the risk for age-related macular degeneration.

Nearly 40,000 Taiwanese residents aged 50 years and older were enrolled in a longitudinal population-based study that used data from the Longitudinal Health Insurance Database and the Taiwan Air Quality Monitoring Database to investigate the risk for AMD after chronic exposure to ambient nitrogen dioxide and carbon monoxide. The subjects lived in areas with air quality monitors and did not have AMD at the time of enrollment.

The concentrations of air pollutants were grouped into four levels, and researchers adjusted for age, sex, social status and comorbidities.

During the 11 years of follow-up, 1,442 individuals developed AMD, with participants in the lowest NO2 exposure areas having the lowest incidence of AMD and those in the highest exposure areas having the highest incidence of AMD. A similar trend was observed with CO exposure.

“We found that long-term exposure to the highest quartile of NO2 significantly increased the risk for AMD by almost twofold even after adjusting for potential confounding factors,” the study authors wrote. “Similarly, exposure to the highest quartile of CO also increased the risk for AMD by 84%.”

Those in the highest level NO2 quartile had an AMD incidence of 51.52 per 10,000 person-years compared with 25.60 per 10,000 person-years for those in the lowest exposure group. The incidence of AMD in the highest level CO exposure group was 56.24 per 10,000 person-years compared with 28.89 per 10,000 person-years in the lowest exposure group.

The study did not include information on AMD risk factors such as smoking, genetic variants and inflammatory status. – by Rebecca L. Forand

 

Disclosures: The authors report no relevant financial disclosures.

High rates of exposure to traffic-related air pollution may increase the risk for age-related macular degeneration.

Nearly 40,000 Taiwanese residents aged 50 years and older were enrolled in a longitudinal population-based study that used data from the Longitudinal Health Insurance Database and the Taiwan Air Quality Monitoring Database to investigate the risk for AMD after chronic exposure to ambient nitrogen dioxide and carbon monoxide. The subjects lived in areas with air quality monitors and did not have AMD at the time of enrollment.

The concentrations of air pollutants were grouped into four levels, and researchers adjusted for age, sex, social status and comorbidities.

During the 11 years of follow-up, 1,442 individuals developed AMD, with participants in the lowest NO2 exposure areas having the lowest incidence of AMD and those in the highest exposure areas having the highest incidence of AMD. A similar trend was observed with CO exposure.

“We found that long-term exposure to the highest quartile of NO2 significantly increased the risk for AMD by almost twofold even after adjusting for potential confounding factors,” the study authors wrote. “Similarly, exposure to the highest quartile of CO also increased the risk for AMD by 84%.”

Those in the highest level NO2 quartile had an AMD incidence of 51.52 per 10,000 person-years compared with 25.60 per 10,000 person-years for those in the lowest exposure group. The incidence of AMD in the highest level CO exposure group was 56.24 per 10,000 person-years compared with 28.89 per 10,000 person-years in the lowest exposure group.

The study did not include information on AMD risk factors such as smoking, genetic variants and inflammatory status. – by Rebecca L. Forand

 

Disclosures: The authors report no relevant financial disclosures.

    Perspective

    The current hypothesis for the formation of age-related macular degeneration is a combination of oxidative stress, genetic predisposition and environmental factors. This oxidative damage leads to the deposition of lipids, proteins and nucleic acids, ending in tissue injury and inflammation. It is well known that smoking increases the risk for AMD and severity and size of CNV in experimental models. And while smoking has been considered the primary way for increased oxidative stress, most recently environmental factors, such as pollution, have also been brought forward as an alternative method of driving AMD prevalence.

    In this study by Chang and colleagues, the authors report a higher odds ratio of 1.91 for those in the highest NO2 quartile and 1.84 for the highest CO quartile for developing AMD. While air pollution has not directly been reported to be a risk factor for AMD, this association is important to confirm with larger studies. The study has significant drawbacks including the lack of smoking, genetic variants and inflammatory status of these patients. The baseline information notwithstanding still shows a plausible mechanism for increased prevalence and thus might be helpful to both patients and clinicians in screening populations at risk.

    • Rishi P. Singh, MD
    • Staff physician, Cole Eye Institute Medical director, Clinical Systems Office, Cleveland Clinic

    Disclosures: Singh reports he is a consultant for Alcon, Regeneron, Novartis and Genentech and has research sponsored by Apellis.