Clinical significance of metabolic quantification for retinal nonperfusion in diabetic retinopathy

Abstract

Diabetic retinopathy (DR) is characterized by microvascular changes including ischemia. Degradation and metabolic changes of various retinal cells occur during ischemia. Ischemic region containing more cells will lead to greater metabolic impairment. We analyzed the non-perfusion region (NPR) by integrating histologic mapping with ultra-widefield fluorescein angiography (UWF FA) images. We also investigated the correlations of the weighted ischemic index (ISI) considering the regional distribution of retinal cells with cytokines, macular edema (ME), and neovascularization (NV). In this study, 32 patients with treatment-naïve DR and 21 age-matched control participants were included. The difference between the non-weighted and weighted ISI of NPR with leakage was greatest at the posterior region. The weighted ISI of NPR with leakage was correlated with MCP-1, IL-8, IL-6, PlGF, and VEGF-A levels, while the non-weighted ISI of NPR with leakage was correlated with IL-8 and IL-6 levels. The presence of baseline ME or NV in patients with DR was associated with the weighted ISI, with a stronger association when cones and rods were weighted. The weighted ISI reflecting both metabolic activity and cell distribution demonstrated a better correlation with clinical features and was more valuable in NPR with leakage than non-weighted ISI, which previous studies conventionally used.

Nicotinamide Mononucleotide Protects against Retinal Dysfunction in a Murine Model of Carotid Artery Occlusion

“…Nonetheless, retinal thickness could be affected by retinal ischemic insults in humans [ 29 , 30 , 31 , 32 ]. Although there exist gaps between mice and humans, it can be speculated that retinal ischemia in humans is closely combined with systemic metabolic stress [ 33 , 34 , 35 ], while the experimental UCCAO murine model has no such stress. To solve this issue, the UCCAO model can be combined with systemic metabolic dysregulation such as streptozotocin injection (to induce systemic diabetic conditions) or genetic manipulation (to cause metabolic diseases or conditions of interest) [ 36 , 37 , 38 , 39 ].…”

Peripheral and central capillary non-perfusion in diabetic retinopathy: An updated overview

“…A novel approach developed by Jeong et al ( 31 ) considered not only the NPAs, but also the spacial density of rod, cones and ganglion cells in the retina, to calculate the ratio of the cell number in the non-perfused retina to the cell number in the total retina, which they called “weighted ISI.” With this technique, they were able to find a correlation between weighted ISI, the level of various cytokines and DME, suggesting that the damage of more metabolically active regions plays a pivotal role in generating DME ( 31 ).…”