IL17A and keratoconus: Alterations in various inflammatory mediators, including tumor necrosis factor-alpha (TNF-α), interleukins (IL-1α/β, IL-6, IL-8, IL-17, IL-4, and IL-13), interferon-gamma (IFN-γ), and immunoglobulin E (IgE), have been found in the corneal tissues, tear film, and aqueous humor of keratoconus patients (3, 23–27).