An Otsuka Long-Evans Tokushima Fatty (OLETF) rat provides a useful model for studies to develop corneal wound healing drugs for use in diabetic keratopathy resulting from
type 2 diabetes mellitus. We investigated the effects of
sericin on corneal wound healing in OLETF rats. Corneal
wounds were prepared by removal of the corneal epithelium and documented using a TRC-50X.
Sericin was instilled into the eyes of rats five times a day following
corneal abrasion. The plasma levels of
glucose,
triglycerides,
cholesterol and
insulin in 38 wk old OLETF rats were significantly higher than in normal control rats (LETO rats), and the rate of corneal wound healing in OLETF rats was slower than in normal rat, probably due to the suppression of cell migration and proliferation caused by high plasma
glucose levels. The corneal
wounds of OLETF rats instilled with saline showed almost complete healing 72 h after corneal epithelial abrasion. On the other hand, the instillation of
sericin has a potent effect in promoting wound healing and
wound size reduction in OLETF rats and the
wounds showed almost complete healing at 48 h after abrasion. The
sericin may be an effective and safe
drug to promote corneal wound healing in diabetic keratopathy.