Table 4.
Ocular symptoms and signs according to season.
| Spring | Summer | Fall | Winter | P-value | |
|---|---|---|---|---|---|
| Ocular surface disease index | 36.7 ± 22.3 | 31.6 ± 19.4 | 35.4 ± 20.4 | 35.1 ± 21.5 | 0.51a |
| Dry eye severity level | 2.0 ± 0.4 | 2.1 ± 0.5 | 2.0 ± 0.5 | 2.0 ± 0.5 | 0.85a |
| Dry eye severity level 1 (% within season) | 8.5 | 10.2 | 10.2 | 10 | – |
| Dry eye severity level 2 (% within season) | 81.5 | 71.4 | 75.8 | 75.4 | – |
| Dry eye severity level 3 (% within season) | 9.5 | 18.4 | 14 | 14.7 | – |
| Dry eye severity level 4 (% within season) | 0.5 | 0 | 0 | 0 | – |
| Tear film breakup time | 5.0 ± 3.9 | 6.7 ± 10.1 | 5.6 ± 3.9 | 4.9 ± 3.9 | 0.34a |
| Ocular protection index | 2.1 ± 2.2 | 2.7 ± 2.6 | 2.0 ± 1.6 | 1.8 ± 1.7 | 0.06a |
| Ocular surface staining | 1.5 ± 2.0 | 1.6 ± 2.2 | 1.5 ± 2.0 | 1.7 ± 2.1 | 0.67a |
| Schirmer I | 16.1 ± 10.5 | 10.1 ± 7.5b | 15.8 ± 10.3 | 15.4 ± 10.3 | 0.002a |
| Tear meniscus height (% < 0.2 mm) | 11.9 | 16.0 | 29.2d | 8.7 | < 0.001c |
| Meibum expressibility | 1.1 ± 0.9 | 0.7 ± 0.8 | 1.0 ± 0.9 | 1.0 ± 0.9 | 0.051a |
| Intraocular pressure | 13.9 ± 3.2 | 12.9 ± 2.4 | 13.1 ± 3.6 | 15.1 ± 3.7e | < 0.001a |
aOne-way analysis of variance; bP < 0.01 compared to all other seasons (Tukey post hoc test); cChi-square test; dhigher percentage than expected (P < 0.001; Chi-square test); eP < 0.05 compared to summer and fall (Tukey post hoc test); Bold font = statistically significant.