Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, 600 006, India.
Department of Zoology, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, 641 043, India.
Acta Neurol Belg. 2020 Apr;120(2):257-265. doi: 10.1007/s13760-020-01274-w. Epub 2020 Jan 21.
Visual disorder is one of the non-motor symptoms found in Parkinson's disease (PD). It can be easily identified in the early stages even before the spread of pathological conditions to the brain parts. Studies have revealed that loss of dopamine (DA) cells in retinal layers is a prime cause for both retinal disturbance and pathological conditions of PD. This reduction of DA in retina is due to the aggregation of phosphorylated α-synuclein (aSyn) in the intra-retinal region, which eventually results in visual impairment in PD. Until now, very limited studies have been focused on the mechanism of aSyn influence and DA depletion as a cause for both retinal layer dysfunction and PD. Thus, more research is warranted to provide the missing connection between the exact role of DA and aSyn as a risk factor for visual problems in PD. Hence, the current review's focus is on the function and effects of DA degeneration in retinal cells of PD. Further, we suggest that iron plays a major role in regulating the aggregation of aSyn in the DA cells of retina and brain in PD. The study finds that the unidentified pathophysiological role of retinal degeneration in PD is an essential biomarker that needs further investigation to use it as a novel therapy in treating retinal dysfunctions in PD.
视觉障碍是帕金森病（PD）中发现的非运动症状之一。即使在病理状况扩散到大脑部位之前，它也可以在早期阶段轻松识别。研究表明，视网膜层中多巴胺（DA）细胞的丧失是视网膜紊乱和 PD 病理状况的主要原因。这种视网膜中 DA 的减少是由于磷酸化α-突触核蛋白（aSyn）在视网膜内区域的聚集，这最终导致 PD 中的视力障碍。到目前为止，很少有研究集中在 aSyn 影响和 DA 耗竭作为视网膜层功能障碍和 PD 的原因的机制上。因此，需要进行更多的研究以提供 DA 和 aSyn 作为 PD 中视觉问题风险因素的确切作用之间缺失的联系。因此，当前综述的重点是 PD 中视网膜细胞中 DA 退化的功能和影响。此外，我们认为铁在调节 PD 中视网膜和大脑 DA 细胞中 aSyn 的聚集中起主要作用。该研究发现，PD 中视网膜退化的未识别病理生理作用是一个重要的生物标志物，需要进一步研究以将其用作治疗 PD 中视网膜功能障碍的新疗法。
