Retinal blood oxygen saturation and aqueous humour biomarkers in early diabetic retinopathy

摘要

Abstract Purpose The aim of this study was to assess the relationship between retinal blood oxygen saturation ( SO 2 ) and specific aqueous humour ( AH ) concentrations of proangiogenic biomarkers in diabetic patients with nonproliferative diabetic retinopathy ( NPDR ) and to compare them with those of matched control subjects. Methods The sample comprised 14 participants with mild‐to‐moderate NPDR (69.1?±?6.6?years) and 17 age‐matched healthy controls (69.7?±?6.3?years); all participants were previously scheduled for routine cataract extraction with intraocular lens implantation. Multiplex cytokine analyses of specific biomarkers, including vascular endothelial growth factor A ( VEGF ‐A), angiopoietin2 (Ang2), epidermal growth factor ( EGF ), hepatocyte growth factor ( HGF ) and interleukin‐8 ( IL ‐8) were performed by BioPlex 200 system. Six non‐invasive hyperspectral retinal images were acquired. Results Mean SO 2 was significantly higher in both arterioles (94.4?±?1.9 versus 93.0?±?1.6) and venules (64.4?±?5.6 versus 55.9?±?4.8) of NPDR than in the healthy controls (p??0.001). AH levels of HGF (p?=?0.018), Ang2 (p?=?0.005) and IL ‐8 (p?=?0.034) were significantly higher, and EGF (p?=?0.030) was significantly lower in NPDR subjects. The study demonstrated a correlation between venular retinal blood oxygen saturation and proangiogenic factors HGF ( r ?=?0.558, p?=?0.038), Ang2 ( r ?=?0.556, p?=?0.039) and EGF ( r? =??0.554, p?=?0.040), but did not find any correlation for IL ‐8 ( r ?=?0.330, p?=?0.249) even though this biomarker was significantly higher in the diabetic group. Conclusion To our knowledge, the present study is the first report considering the association between SO 2 and AH concentrations of protein biomarkers in diabetic retinopathy. The biomarkers of interest have been shown to participate in cell death, which may explain higher oxygen saturation in NPDR .