John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
Vis Neurosci. 2020 Oct 6;37:E008. doi: 10.1017/S0952523820000097.
Based on clinical findings, diabetic retinopathy (DR) has traditionally been defined as a retinal microvasculopathy. Retinal neuronal dysfunction is now recognized as an early event in the diabetic retina before development of overt DR. While detrimental effects of diabetes on the survival and function of inner retinal cells, such as retinal ganglion cells and amacrine cells, are widely recognized, evidence that photoreceptors in the outer retina undergo early alterations in diabetes has emerged more recently. We review data from preclinical and clinical studies demonstrating a conserved reduction of electrophysiological function in diabetic retinas, as well as evidence for photoreceptor loss. Complementing in vivo studies, we discuss the ex vivo electroretinography technique as a useful method to investigate photoreceptor function in isolated retinas from diabetic animal models. Finally, we consider the possibility that early photoreceptor pathology contributes to the progression of DR, and discuss possible mechanisms of photoreceptor damage in the diabetic retina, such as enhanced production of reactive oxygen species and other inflammatory factors whose detrimental effects may be augmented by phototransduction.
基于临床发现，糖尿病性视网膜病变（DR）传统上被定义为视网膜微血管病变。现在已经认识到，在明显的 DR 发生之前，视网膜神经元功能障碍是糖尿病视网膜的早期事件。虽然糖尿病对视网膜内层细胞（如视网膜神经节细胞和无长突细胞）的存活和功能有不利影响已被广泛认可，但最近有证据表明，外视网膜中的光感受器在糖尿病中也会发生早期改变。我们回顾了来自临床前和临床研究的数据，这些数据表明糖尿病视网膜中存在电生理功能的一致性降低，以及光感受器丧失的证据。我们补充了体内研究，讨论了离体视网膜眼电图技术作为一种有用的方法，可用于研究糖尿病动物模型中分离的光感受器的功能。最后，我们考虑了早期光感受器病理学是否有助于 DR 的进展，并讨论了糖尿病视网膜中光感受器损伤的可能机制，例如活性氧物质和其他炎症因子的产生增加，其有害影响可能会被光转导增强。
