Synchrotron radiation‐based infrared micro‐spectroscopy characterization of different types of epiretinal proliferations

Abstract

AbstractPurpose: To assess epiretinal proliferations bio‐macromolecules and to provide their molecular fingerprint for better understanding of epiretinal proliferations, we used synchrotron radiation‐based Fourier transform infrared (SR‐FTIR) micro‐spectroscopy.Methods: The membranes were collected from routine pars plana vitrectomy. The biochemical differences between idiopathic nonvascular epiretinal membranes (ERMi), membranes in proliferative vitreoretinopathy (PVRm) and neovascular membranes in proliferative diabetic retinopathy (PDRm) were evaluated and compared by using SR‐FTIR micro‐spectroscopy at the MIRAS beamline of the ALBA Synchrotron, Barcelona, Spain and multivariate analysis.Results: PVRm differs the most from ERMi and PDRm in all spectral regions. We demonstrated the presence of silicone oil (SO) or polydimethylsiloxane (PDMS) in the structure of PVRm membrane after SO endotamponade suggesting that SO, in addition to many benefits as an important tool in vitreoretinal surgery, can also contribute in PVRm formation. We also showed the differences between PVRm, PDRm and ERMi in protein and lipid structure, collagen content and maturity.Conclusions: Our results obtained by SR‐FTIR increase the knowledge about the total proteins, lipids and nucleic acids in different epiretinal proliferations while offering also the evidence that SR‐FTIR is sensitive to the pathologic processes of epiretinal proliferations. We emphasize the different macro‐molecular composition of three different types of epiretinal proliferation stemming from different components and metabolic processes taking place as well as the caution needed when using SO in vitreoretinal surgery.