Hui-Chen Cheng1, Ren-Hao Pan2, Huan-Jui Yeh3, K Robert Lai2, May-Yung Yen1, Chien-Lung Chan4, An-Guor Wang5. 1. Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Ophthalmology, School of Medicine, National Yang-Ming University, Taipei, Taiwan. 2. Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Taiwan; Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan. 3. Department of Physical Medicine and Rehabilitation, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan; Institute of Public Health, National Yang-Ming University, Taipei, Taiwan. 4. Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Taiwan; Department of Information Management, Yuan Ze University, Taoyuan, Taiwan. 5. Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Ophthalmology, School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: agwang@vghtpe.gov.tw.
Abstract
PURPOSE: To investigate whether daily changes in ambient air pollution were associated with an increased risk of central retinal artery occlusion (CRAO). DESIGN: Retrospective population-based cohort study. PARTICIPANTS: We identified patients newly diagnosed with CRAO between 2001 and 2013 in a representative database of 1 000 000 patients that were randomly selected from all registered beneficiaries of the National Health Insurance program in Taiwan. We identified air pollutant monitoring stations located near these patients' residences in different administrative areas in Taiwan to determine the recorded concentrations of particulate matter ≤2.5 μm (PM2.5), particulate matter ≤10 μm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3). Patients without corresponding monitoring stations were excluded. METHODS: We used a time-stratified case-crossover study design and conditional logistic regression analysis to assess associations between the risk of CRAO and the air pollutant levels in the days preceding each event. MAIN OUTCOME MEASURES: Odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: We enrolled 96 patients with CRAO in this study. The mean age was 65.6 years (standard deviation, 12.7 years) and 67.7% of patients were male. The risk of CRAO onset was significantly increased (OR, 1.09; 95% CI, 1.01-1.17; P = 0.03) during a 5-day period following a 1 part per billion increase in NO2 levels. After multipollutant adjustment, the increase in risk was most prominent after 4 days (OR, 1.40; 95% CI, 1.05-1.87; P = 0.02) to 5 days (OR, 2.16; 95% CI, 1.10-4.23; P = 0.03) of elevated NO2 levels in diabetic patients. The risk of CRAO onset also significantly increased in patients with hypertension and in patients ≥65 years old, after 1 day of elevated SO2 levels (OR, 1.88; 95% CI, 1.07-3.29; P = 0.03 and OR, 1.90; 95% CI, 1.13-3.21; P = 0.02, respectively). The transient concentration of the other air pollutants, including PM2.5, PM10, and O3, did not significantly affect the occurrence of CRAO in this study. CONCLUSIONS: These results demonstrated a positive association between air pollution and CRAO onset, particularly in patients with diabetes or hypertension and those older than 65 years.
PURPOSE: To investigate whether daily changes in ambient air pollution were associated with an increased risk of central retinal artery occlusion (CRAO). DESIGN: Retrospective population-based cohort study. PARTICIPANTS: We identified patients newly diagnosed with CRAO between 2001 and 2013 in a representative database of 1 000 000 patients that were randomly selected from all registered beneficiaries of the National Health Insurance program in Taiwan. We identified air pollutant monitoring stations located near these patients' residences in different administrative areas in Taiwan to determine the recorded concentrations of particulate matter ≤2.5 μm (PM2.5), particulate matter ≤10 μm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3). Patients without corresponding monitoring stations were excluded. METHODS: We used a time-stratified case-crossover study design and conditional logistic regression analysis to assess associations between the risk of CRAO and the air pollutant levels in the days preceding each event. MAIN OUTCOME MEASURES: Odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: We enrolled 96 patients with CRAO in this study. The mean age was 65.6 years (standard deviation, 12.7 years) and 67.7% of patients were male. The risk of CRAO onset was significantly increased (OR, 1.09; 95% CI, 1.01-1.17; P = 0.03) during a 5-day period following a 1 part per billion increase in NO2 levels. After multipollutant adjustment, the increase in risk was most prominent after 4 days (OR, 1.40; 95% CI, 1.05-1.87; P = 0.02) to 5 days (OR, 2.16; 95% CI, 1.10-4.23; P = 0.03) of elevated NO2 levels in diabeticpatients. The risk of CRAO onset also significantly increased in patients with hypertension and in patients ≥65 years old, after 1 day of elevated SO2 levels (OR, 1.88; 95% CI, 1.07-3.29; P = 0.03 and OR, 1.90; 95% CI, 1.13-3.21; P = 0.02, respectively). The transient concentration of the other air pollutants, including PM2.5, PM10, and O3, did not significantly affect the occurrence of CRAO in this study. CONCLUSIONS: These results demonstrated a positive association between air pollution and CRAO onset, particularly in patients with diabetes or hypertension and those older than 65 years.