TABLE 3.
Effects of air pollutants on ocular surface using single-pollutant models.
| PM2.5 (per 1 μ g/m3) |
PM10 (per 1 μ g/m3) |
O3 (per 1 ppb increase) |
SO2 (per 1 μ g/m3) |
NO2 (per 1 μ g/m3) |
||||||
| Estimate (95% CI) | p | Estimate (95% CI) | p | Estimate (95% CI) | p | Estimate (95% CI) | p | Estimate (95% CI) | p | |
| OSDI | ||||||||||
| 1 day | −0.075 (−0.276 to 0.125) | 0.459 | −0.047 (−0.139 to 0.045) | 0.317 | 0.414 (0.178 to 0.528) ** | 0.004 | 0.402 (0.127 to 0.677) ** | 0.004 | 0.101 (−0.096 to 0.298) | 0.314 |
| 1 week | 0.209 (−0.092 to 0.511) | 0.172 | 0.147 (0.021 to 0.314) | 0.086 | 0.454 (0.186 to 0.753) ** | 0.001 | 0.520 (0.084 to 0.956) ** | 0.020 | 0.279 (0.034 to 0.591) | 0.080 |
| 1 month | 0.330 (0.122 to 0.783) | 0.152 | 0.109 (−0.180 to 0.398) | 0.459 | 0.486 (0.164 to 0.796) ** | 0.000 | 0.051 (−0.463 to 0.565) | 0.844 | −0.121 (−0.483 to 0.242) | 0.513 |
| ST | ||||||||||
| 1 day | 0.044 (−0.038 to 0.127) * | 0.039 | −0.006 (−0.048 to 0.036) | 0.782 | −0.113 (−0.158 to −0.032) * | 0.043 | 0.068 (−0.064 to 0.200) | 0.313 | −0.007 (−0.093 to 0.079) | 0.868 |
| 1 week | 0.121 (0.009 to 0.233) * | 0.034 | 0.032 (0.008 to 0.111) | 0.434 | −0.133 (−0.221 to −0.087) * | 0.032 | 0.015 (−0.276 to 0.307) | 0.917 | −0.058 (−0.212 to 0.097) | 0.463 |
| 1 month | 0.166 (0.014 to 0.319) * | 0.033 | 0.093 (−0.041 to 0.277) | 0.173 | −0.191 (−0.283 to −0.091) ** | 0.003 | 0.181 (−0.071 to 0.433) | 0.818 | −0.323 (−0.492 to −0.154) ** | 0.000 |
| TMH | ||||||||||
| 1 day | −0.087 (−0.113 to −0.002) ** | 0.009 | −0.095 (−0.158 to −0.003) ** | 0.000 | −0.089 (−0.161 to −0.006) ** | 0.000 | −0.001 (−0.009 to 0.007) | 0.791 | −0.011 (−0.016 to −0.006) ** | 0.000 |
| 1 week | 0.006 (−0.002 to 0.014) | 0.156 | −0.116 (−0.201 to −0.011) ** | 0.007 | −0.166 (−0.209 to −0.014) ** | 0.000 | 0.011 (0.000 to 0.023) | 0.059 | −0.019 (−0.028 to −0.010) ** | 0.000 |
| 1 month | −0.014 (−0.026 to −0.003) * | 0.017 | −0.210 (−0.317 to −0.102) * | 0.012 | −0.189 (−0.225 to −0.013) ** | 0.000 | 0.016 (0.003 to 0.029)* | 0.059 | −0.034 (−0.044 to −0.025) ** | 0.000 |
| TBUT | ||||||||||
| 1 day | −0.074 (−0.112 to −0.036) ** | 0.000 | 0.006 (−0.012 to 0.023) | 0.516 | −0.020 (−0.040 to −0.001) * | 0.041 | −0.127 (−0.175 to −0.078) ** | 0.000 | 0.034 (−0.003 to 0.071) | 0.068 |
| 1 week | −0.066 (−0.113 to −0.018) ** | 0.007 | −0.028 (−0.042 to −0.018) * | 0.034 | 0.022 (−0.001 to 0.046) | 0.065 | −0.272 (−0.350 to −0.193) ** | 0.000 | 0.048 (−0.008 to 0.104) | 0.093 |
| 1 month | −0.100 (−0.183 to −0.016) * | 0.019 | −0.029 (−0.036 to −0.011) * | 0.010 | −0.031 (−0.074 to 0.011) | 0.148 | 0.206 (−0.301 to −0.111) ** | 0.000 | −0.040 (−0.107 to 0.027) | 0.240 |
| CFS | ||||||||||
| 1 day | −0.001 (−0.027 to 0.024) | 0.925 | 0.028 (0.017 to 0.040) ** | 0.000 | 0.018 (0.005 to 0.031) ** | 0.000 | 0.089 (0.054 to 0.123) ** | 0.000 | 0.051 (0.026 to 0.076) ** | 0.000 |
| 1 week | 0.107 (0.060 to 0.134) ** | 0.000 | 0.045 (0.028 to 0.073) ** | 0.000 | 0.009 (−0.007 to 0.025) | 0.278 | 0.124 (0.071 to 0.178) ** | 0.000 | 0.019 (−0.019 to 0.058) | 0.318 |
| 1 month | 0.150 (0.093 to 0.208) ** | 0.000 | 0.073 (0.037 to 0.110) ** | 0.000 | 0.018 (−0.012 to 0.047) | 0.235 | 0.122 (0.057 to 0.188) ** | 0.000 | 0.104 (0.058 to 0.150) ** | 0.000 |
| MG expression | ||||||||||
| 1 day | 0.009 (−0.002 to 0.019) | 0.119 | 0.003 (−0.002 to 0.008) | 0.206 | 0.009 (0.003 to 0.015) | 0.052 | 0.017 (0.002 to 0.032) | 0.053 | 0.004 (−0.007 to 0.014) | 0.477 |
| 1 week | 0.011 (−0.006 to 0.027) | 0.203 | 0.013 (0.003 to 0.029) | 0.103 | 0.001 (−0.006 to 0.009) | 0.707 | 0.017 (−0.007 to 0.040) | 0.168 | −0.009 (−0.026 to 0.008) | 0.295 |
| 1 month | 0.035 (0.011 to 0.060) ** | 0.005 | 0.019 (0.009 to 0.021) * | 0.045 | 0.015 (0.002 to 0.028) ** | 0.020 | 0.003 (−0.025 to 0.032) | 0.808 | 0.022 (0.002 to 0.042) * | 0.033 |
| MG secretion | ||||||||||
| 1 day | −0.003 (−0.016 to 0.009) | 0.593 | 0.001 (−0.005 to 0.007) | 0.727 | 0.005 (−0.002 to 0.011) | 0.172 | 0.021 (0.004 to 0.038) | 0.068 | 0.023 (0.010 to 0.035) ** | 0.000 |
| 1 week | 0.001 (−0.017 to 0.019) | 0.907 | −0.003 (−0.013 to 0.008) | 0.617 | 0.007 (−0.001 to 0.015) | 0.098 | 0.011 (−0.015 to 0.038) | 0.396 | 0.039 (0.020 to 0.058) ** | 0.000 |
| 1 month | 0.013 (−0.014 to 0.040) | 0.336 | 0.003 (−0.015 to 0.020) | 0.758 | 0.068 (0.046 to 0.089) ** | 0.000 | −0.022 (−0.053 to 0.008) | 0.153 | 0.068 (0.046 to 0.089) ** | 0.000 |
| MG loss | ||||||||||
| 1 day | 0.021 (0.009 to 0.034) ** | 0.001 | 0.013 (0.001 to 0.024) * | 0.028 | 0.016 (0.010 to 0.023) ** | 0.000 | 0.003 (0.002 to 0.014) | 0.720 | 0.007 (−0.005 to 0.020) | 0.250 |
| 1 week | 0.012 (−0.005 to 0.029) * | 0.011 | 0.015 (0.006 to 0.024) ** | 0.002 | 0.019 (0.007 to 0.026) * | 0.023 | −0.004 (−0.029 to 0.020) | 0.725 | 0.006 (−0.011 to 0.024) | 0.486 |
| 1 month | 0.075 (0.051 to 0.100) ** | 0.000 | 0.024 (0.009 to 0.040) ** | 0.003 | 0.025 (0.012 to 0.037) ** | 0.000 | −0.002 (−0.030 to 0.026) | 0.899 | 0.025 (0.006 to 0.045) * | 0.012 |
| IL-1β | ||||||||||
| 1 day | −0.007 (−0.015 to 0.001) | 0.093 | −0.002 (−0.006 to 0.001) | 0.190 | 0.001 (0.000 to 0.005) | 0.569 | −0.006 (−0.017 to 0.005) | 0.266 | 0.006 (−0.002 to 0.014) | 0.130 |
| 1 week | 0.011 (−0.001 to 0.021) * | 0.025 | 0.009 (0.002 to 0.015) * | 0.010 | 0.005 (0.002 to 0.013) | 0.169 | 0.004 (−0.014 to 0.021) | 0.674 | 0.006 (−0.008 to 0.021) | 0.406 |
| 1 month | 0.046 (−0.004 to 0.096) | 0.069 | 0.010 (0.009 to 0.029) | 0.313 | 0.007 (−0.005 to 0.020) | 0.255 | 0.011 (−0.008 to 0.030) | 0.254 | −0.009 (−0.027 to 0.009) | 0.336 |
| IL-6 | ||||||||||
| 1 day | −0.013 (−0.026 to 0.001) | 0.062 | 0.015 (0.001 to 0.031) * | 0.042 | 0.018 (−0.003 to 0.038) * | 0.040 | −0.002 (−0.019 to 0.015) | 0.819 | 0.016 (0.003 to 0.029) * | 0.015 |
| 1 week | 0.002 (−0.033 to 0.029) | 0.896 | 0.009 (−0.020 to 0.019) | 0.103 | 0.005 (−0.017 to 0.008) | 0.468 | 0.000 (−0.029 to 0.028) | 0.985 | 0.026 (0.002 to 0.049) * | 0.034 |
| 1 month | 0.042 (−0.038 to 0.122) | 0.300 | 0.001 (−0.004 to 0.007) | 0.604 | −0.004 (−0.011 to 0.003) | 0.282 | 0.005 (−0.026 to 0.036) | 0.753 | 0.035 (0.006 to 0.064) * | 0.019 |
| IL-8 | ||||||||||
| 1 day | 0.018 (0.004 to 0.031) ** | 0.009 | 0.013 (0.000 to 0.025) * | 0.045 | −0.006 (−0.013 to 0.001) | 0.070 | 0.005 (−0.012 to 0.022) | 0.542 | 0.013 (0.000 to 0.025) * | 0.044 |
| 1 week | 0.017 (−0.015 to 0.050) | 0.291 | 0.001 (−0.010 to 0.012) | 0.843 | 0.003 (−0.010 to 0.016) | 0.614 | 0.009 (−0.021 to 0.038) | 0.556 | −0.001 (−0.025 to 0.024) | 0.946 |
| 1 month | 0.028 (−0.055 to 0.111) | 0.509 | −0.016 (−0.032 to 0.001) | 0.065 | 0.004 (−0.017 to 0.025) | 0.715 | 0.015 (−0.017 to 0.047) | 0.372 | 0.015 (−0.015 to 0.045) | 0.321 |
| VEGF | ||||||||||
| 1 day | 0.014 (0.002 to 0.025) | 0.018 | 0.011 (0.000 to 0.022) * | 0.043 | 0.006 (0.000 to 0.012) | 0.061 | −0.002 (−0.017 to 0.012) | 0.762 | 0.010 (−0.001 to 0.021) | 0.073 |
| 1 week | 0.003 (−0.024 to 0.030) | 0.821 | −0.001 (−0.011 to 0.008) | 0.807 | −0.003 (−0.014 to 0.008) | 0.555 | −0.014 (−0.039 to 0.011) | 0.259 | −0.015 (−0.035 to 0.006) | 0.163 |
| 1 month | 0.057 (−0.012 to 0.127) | 0.107 | 0.012 (−0.001 to 0.026) | 0.080 | 0.006 (−0.012 to 0.023) | 0.532 | −0.001 (−0.028 to 0.026) | 0.951 | −0.020 (−0.045 to 0.005) | 0.119 |
PM, particulate matter; O3, ozone; SO2, sulfur dioxide; NO2, nitrogen dioxide; CI, confidence interval; OSDI, ocular surface disease index; ST, Schirmer’s I test; TMH, tear meniscus height; TBUT, tear film break-up time; CFS, corneal fluorescein staining; MG, meibomian gland; IL-1β, interleukin 1 beta; IL-6, interleukin 6; IL-8, interleukin 8; VEGF, vascular endothelial growth factor. The Estimate (95% CI) and p value are shown for all significant associations in bold. *p < 0.05; **p < 0.01.