<正>Dear Editor,Keratoconus is a progressive,non-inflammatory disease of the cornea,which is characterized by marked corneal steepening and thinning[1].It induces myopia and irregular astigmatism leading frequently to severe visual impairment[1].Although several aetiological factors have been implicated in its pathophysiology,the exact mechanisms underlying keratoconus are not fully elucidated yet.Corneal crosslinking is the treatment of choice in order to inhibit the progression of