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 PM(2.5) 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 (PM(2.5)) 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 PM(2.5) exposure levels were divided into four groups: <25th percentile (Q1), <617 μg/mm(3); 25th to 50th percentile (Q2), 617 to 1297 μg/mm(3); 50th to 75th percentile (Q3), 1297 to 2113 μg/mm(3); and >75th percentile (Q4), >2113 μg/mm(3). 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 PM(2.5) Q1 level, the OR of the PM(2.5) Q2 level was 1.009 (95% CI 0.812–1.254), the PM(2.5) Q3 level was 1.241 (95% CI 1.241–1.537, p < 0.05), and the PM(2.5) 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 PM(2.5) exposure, and PM(2.5) has a concentration–dose effect. It is hoped that in the future, in the clinical judgment of NTG and POAG, the level of PM(2.5) in the environment can be taken as a risk factor.