The role of neuromediators in ocular allergy

To describe and highlight the critical role of neuromediators in ocular allergy, in view of the recent findings indicating that particularly neuropeptides and neurotrophins exert a pivotal role in the complex network of neurogenic inflammation occurring in ocular allergy.

Neuropeptides and neurotrophins represent an interesting group of neuromediators actively taking place in allergic response. Mainly released at the neuronal edge or from immune and/or structural cells, neuropeptides and neurotrophins might either upregulate or downregulate inflammatory processes. These mediators contribute to ocular allergy by acting directly on cells responsible for both early and late phase reactions as well as on epithelial cells and fibroblasts, leading to either self-limiting or chronicity states.

This short review surveys our current knowledge on the functional activity showed by substance P, calcitonin gene-related peptide, vasoactive intestinal peptide, neuropeptide Y and nerve growth factor and integrates their opposing effects in the context of neuroimmune interactions during ocular allergy. In addition, the review will provide implications for the clinical situation and/or future strategies for treating the most severe chronic forms of ocular allergy.