Tear Film Function in Patients with Seasonal Allergic Conjunctivitis Outside the Pollen Season

Abstract

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.

A Murine Model of Acute Allergic Conjunctivitis Induced by Continuous Exposure to Particulate Matter 2.5

“…41,42 The difference is presumably due to the differential effects between PM2.5 and other allergens, as it was reported that seasonal allergic inflammation did not cause permanent tear film instability outside the pollen season. 43 Alternatively, the effects of an allergic induction in the acute phase are likely to differ from those long-term consequences. With long-term AC, tear film stability is usually impaired as a result of reduced conjunctival goblet cell density, often concurrent with decreased tear secretion, making it very difficult to perform differential diagnosis between AC and dry eye.…”

Ocular allergy as a risk factor for dry eye in adults and children

“…Interestingly, a few researches on tear film stability in intermittent forms of OA reported that VKC patients seem to show a shortened BUT even in the quiet phases of the disease, [11] while SAC patients don't have decreased tear film stability outside the pollen season. [17] In the Vicious Circle of DED, tear film instability may be due to different mechanisms, including Meibomian glands (MGs) and lipid layer changes on the one hand and mucins alterations on the other. [18**, 19*] A few imaging studies assessed MGs in different forms of OA, [20*] including AKC, VKC and PAC.…”

Tear film examinations and eyelid histology of pugs

“…A study in humans has shown that seasonal allergic conjunctivitis may result in reversible tear film instability (11). However, no histological examination was performed to confirm the clinical results.…”