Is oxidative stress involved in vernal keratoconjunctivitis? Results from a pilot study in children

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 aimed to assess the oxidative stress in VKC patients and controls and to study the effect of CsA on oxidative stress in these subjects.

Thirty-six consecutive children, including 12 VKC (nine males, 75%; mean age 10.17; SD ± 2.48) patients without treatment, 12 VKC patients treated with CsA (nine males, 75%; mean age 9.08; SD ± 2.75), and 12 controls (CT) (seven males, 58%; mean age 8.58; SD ± 1.78), were recruited. A cross-sectional study was performed to compare H₂ O₂ in the serum with that in the tears of these children.

Compared with CT and VKC children treated with CsA, VKC untreated children had significantly higher values of hydrogen peroxide (H₂ O₂ ) in the serum 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 H₂ O₂ levels.

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.