Abstract
Purpose :
Attenuated endothelium glycocalyx has been shown to be related to vascular damage during diabetic retinpathy (DR). Syndecans are pivotal components of retinal glycocalyx, which could be released from the endothelial surface by a highly regulated proteolytic cleavage. Thus, in the present study, we tested for the associations between diabetic retinal vascular injuries, as evidenced by OCTA metrics, and levels of Syndecan-1 and Syndecan-4 in aqueous humor of diabetic patients.
Methods :
16 eyes with DR, 10 eyes with diabetes but no DR (NDR) and 20 eyes without diabetes (Non-DM) were enrolled in the cross-sectional study. All the participants underwent OCTA scan with 3×3 mm pattern. The images were binarized and skeletonized for quantification. OCT metris of perfusion density (PD), vessel length density (VLD), FAZ area and central subfield thickness (CST) were calculated after large vessels were separated from microvessels by an automatic algrithm. Moreover, the concentration of Syndecans were measured by Luminex Multiplex Immumoassay.
Results :
All vessel PD/VLD, microvascular PD/VLD and CST in DR group were lower than in Non-DM and Non-DR group. However, Large vessel PD/VLD and FAZ-area in DR group was significantly higher than that in Non-DM and Non-DR group. Moreover, higher Syndecan-1 and lower Syndecan-4 levels were detected DR group compared to NDR and Non-DM group. Of note, Syndecan-1 was negatively correlated with all vessel PD/VLD, microvascular PD/VLD, and positively correlated with FAZ-area, CST. Syndecan-4 was positively correlated with microvascular PD and all vessel VLD. Interesting, Syndecan-4 was negatively correlated with large vessel PD/VLD as well as CST.
Conclusions :
Taken together, retinal large vessels tends to dilate instead of constriction in DR. Negative correlation of Syndecan-1 and positive correlation of Syndecan-4 to retinal PD/VLD suggested diverse role of syndecans in diabetic vascular injuries.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.