Raman spectroscopy characterization of diabetes effects on human vitreous in diabetic retinopathy

摘要

Nonenzymatic glycation alters collagen throughout the body, resulting in the histopathology that underlies diabetic disease in several organs. In the eye such changes in vitreous collagen could contribute to the progression of proliferative diabetic retinopathy by inducing vitreous degeneration. In this study, near infrared Fourier-transform Raman spectroscopy was performed on vitreous obtained at surgery from diabetic patients and from non-diabetic control subjects. The findings were compared to measurements obtained in untreated and glycated (in vitro) rat-tail tendon collagen, as well as demineralized chick bone, rich in crosslinks. The results demonstrated substantial changes in diabetic vitreous collagen not resulting from enzyme- mediated crosslinking, but most likely advanced nonenzymatic glycation. This approach appears to be useful as a means of characterizing the molecular changes induced by diabetes. Furthermore, this technique could be developed as a way of quantifying these changes in vivo in several tissues, so as to gauge the severity of disease and monitor the response to therapy.