NGF and Keratoconjunctivitis sicca: Elevated concentrations of NGF have been reported in the tear film of patients with contact-lens-associated dry eye, Sjögren’s syndrome, ocular cicatricial pemphigoid, keratoconjunctivitis sicca, and dry eye following refractive surgery [19,99,131,140,148,155], suggesting that NGF is not consistently deficient across disease states.