Periostin, discovered by nano-flow liquid chromatography and mass spectrometry, is a novel marker of diabetic retinopathy

► In proliferative membrane and epiretinal membrane specimens, the numbers of proteins are 225 and 154, respectively, and 123 proteins are common to both. ► Periostin and thrombospondin-1 proteins are unique to the proliferative membrane specimens. ► The expression of periostin is significantly up-regulated in proliferative membrane specimens.