Department of Ophthalmology, Penn State Hershey Eye Center, Penn State Hershey College of Medicine, Hershey, Pennsylvania 17033, USA.
Invest Ophthalmol Vis Sci. 2011 Feb 28;52(2):1156-63. doi: 10.1167/iovs.10-6293. Print 2011 Feb.
The most striking features of diabetic retinopathy are the vascular abnormalities that are apparent by fundus examination. There is also strong evidence that diabetes causes apoptosis of neural and vascular cells in the retina. Thus, there is good reason to define diabetic retinopathy as a form of chronic neurovascular degeneration. In keeping with the gradual onset of retinopathy in humans, the rate of cell loss in the animal models is insidious, even in uncontrolled diabetes. This is not surprising given that a sustained high rate of cell loss without regeneration would soon lead to catastrophic tissue destruction. The consequences of ongoing cell death are difficult to detect, and even the quantification of cumulative cell loss requires painstaking histology and microscopy. This subtle cell loss raises the issue of the relevance of the phenomenon to the progression of diabetic retinopathy and the ultimate loss of vision. Neuronal function may be compromised in advance of apoptosis, contributing to an early deterioration of vision. Here we review some of the evidence supporting apoptotic cell death as a contributing mechanism of diabetic retinopathy, explore some of the potential causes, and discuss the potential links between apoptosis and loss of visual function in diabetic retinopathy.
糖尿病视网膜病变最显著的特征是眼底检查时明显的血管异常。有强有力的证据表明，糖尿病会导致视网膜神经和血管细胞的凋亡。因此，将糖尿病视网膜病变定义为一种慢性神经血管退行性疾病是有充分理由的。与人类糖尿病视网膜病变的逐渐发生相一致，即使在不受控制的糖尿病中，动物模型中细胞丢失的速度也是隐匿的。考虑到没有再生的持续高细胞丢失率很快会导致灾难性的组织破坏，这并不奇怪。持续的细胞死亡的后果很难被察觉，甚至累计细胞丢失的量化也需要艰苦的组织学和显微镜检查。这种微妙的细胞丢失引发了一个问题，即这种现象与糖尿病视网膜病变的进展和最终视力丧失的相关性。在细胞凋亡之前，神经元功能可能已经受到损害，这导致了视力的早期恶化。在这里，我们回顾了一些支持细胞凋亡作为糖尿病视网膜病变发病机制的证据，探讨了一些潜在的原因，并讨论了糖尿病视网膜病变中细胞凋亡与视觉功能丧失之间的潜在联系。
