Tear film function in patients with seasonal allergic conjunctivitis outside the pollen season.

BACKGROUND: Seasonal allergic conjunctivitis can manifest itself through tear film instability and symptoms of eye discomfort during the pollen season. This study investigated whether seasonal allergic inflammation defines tear film instability outside the season.

METHODS: Twenty-three control subjects and 13 ragweed-allergic patients were involved (21 female, 15 male; mean age 26.6 ± 5.4 years). Outside the pollen season, subjective ocular symptoms, non-invasive tear film break-up time, lower tear meniscus height and the tear lipid layer's interference pattern grade were recorded. C3a complement activation level was also measured in collected tear samples.

RESULTS: Non-invasive tear film break-up time, lower tear meniscus height, C3a complement activation level and the incidence of the different grades of tear lipid pattern did not differ significantly in the two examined groups (p ≥ 0.223). The mean eye symptom score outside the season was greater in the allergic group, but the difference was not significant (p = 0.062). The C3a complement activation level showed a significant and inverse correlation with the lipid layer grade (r = -0.343, p = 0.017). Among the participants with thinner tear lipid layers, the complement activation in the tear samples was higher than among those patients with normal tear lipid layers.

CONCLUSION: Seasonal allergic inflammation did not cause permanent tear film instability and eye symptoms were not observed outside the pollen season.