Background: Vernal keratoconjunctivitis (VKC) is a rare chronic conjunctivitis characterized by a predominantly eosinophil-mediated inflammatory disorder that could develop critical complications such as blindness. Oxidative stress plays a pivotal role in the pathogenesis of several allergic diseases. The role of oxidative stress has been hypothesized in VKC, but no study explored this issue.Furthermore, cyclosporine A (CsA) exerts an anti-inflammatory and antioxidant action on the conjunctiva. This study aims to assess oxidative stress in VKC patients and controls and to study the effect ofCsA on oxidative stress in these subjects. Methods:Thirty-six consecutive children, including 12 VKC(9 males, 75%; mean age 10,17; SD ± 2.48) patients without treatment,12 VKC treated with CsA(9 males, 75%; mean age 9,08; SD± 2.75) and 12 controls (CT) (7males,58%; mean age8,58; SD ±1,78) were recruited. A cross-sectional study was performed to compare H2O2 in the serum and the tears ofthese children. Results: Compared with CT and VKC children treated with CsA, VKCuntreated children had significantly higher values ofHydrogen peroxide (H2O2) in theserum and the tears.No significant differences were observed between CT and VKC treated with CsA. A significant correlation was found at the linear regression analysis between serum and tear H2O2 levels. Conclusion: This study provides the first report attesting that patients with VKC have high oxidative stress; furthermore, it suggests that CsA could have an anti-inflammatory and antioxidant action that could be useful to prevent the poor VKC outcome.

Background: CD14 is involved in the modulation of immune reaction via toll-like receptors (TLR) and may influence the development of allergic diseases. The role of CD14 in vernal keratoconjunctivitis (VKC) has not yet been investigated. The aim of this study is to evaluate changes of tear soluble sCD14 and conjunctival CD14, TLR-4 and 9 expression in patients with VKC in the active and quiescent phases. Methods: 18 patients with VKC during active inflammation (group A, N=9), in the quiescent phase (group Q, N=5) and after recovery (group R, N=4) and 10 healthy subjects were included. Patients in group A were treated with corticosteroid eye drops 4 times daily for 7 days. Expression of sCD14 in tears and of CD14, TLR-4, and TLR-9 by conjunctival epithelium were evaluated by Western Blot in all groups and after corticosteroid treatment. Results: expression of sCD14 and of CD14, TLR-4 and TLR-9 was significantly decreased in group A when compared with healthy subjects and with VKC group Q and R. Lower expression of sCD14, CD14, TLR-4 and TLR-9 were significantly correlated with the severity of papillary reaction, while the lower sCD14 was correlated with severity of conjunctival hyperemia. Conjunctival expression of TLR-4, but not sCD14, CD14 and TLR-9, was significantly reduced after topical corticosteroid treatment. Conclusion: tear sCD14, and conjunctival CD14, TLR4 and TLR-9 decreased during ocular surface inflammatory reaction in patients with VKC. CD14 and TLRs may represent potential therapeutic targets, although it requires further studies.