Fig. 4

Insulin eye drops enhance expression levels of the neuropeptides. (A) Representative images of immunofluorescence staining of the whole cornea labeled with CGRP (red), SP (green) and DAPI (blue) (n = 3). The intensity of neurotrophic factors in the whole-mount cornea were quantified by Image J software. Data were exhibited as average ± SD; *P < 0.05. (B) and (C) are representative images of the corneal sections, showing the positions of CGRP (red) and SP (green), as indicated by the white arrows. Scale bars: 500 μm, 100 μm, and10µm. DM-In, diabetic mice with topical insulin treatment; DM-Con, diabetic mice with topical physiological saline treatment; Ep, corneal epithelium; St, corneal stroma