Correlation of vascular change and cognitive impairment in age-related macular degeneration patients

Age-related macular degeneration (AMD) is one of the leading causes of blindness among the elderly. However, the correlation between vascular change and cognitive impairment in AMD disease is still unknown. In our study, we investigate the blood flow change among different layers of the retina in the AMD eye and normal fellow eye of AMD patients and its influence with patients' cognition. Our study applies optical coherence tomography angiography (OCTA) to assess the blood flow of the retina in AMD patients and the healthy controls (HCs). Magnetic resonance imaging (MRI) and Montreal Cognitive Assessment (MoCA) were performed to evaluate the cognitive change of the individuals. The results showed that deep capillary plexus density, superficial capillary plexus density, retina thickness and retinal nerve fiber layer thickness deduction existed in both eyes of the AMD patient compared with the HCs. The reduced vessel density in the choroidal layer only existed in the AMD eye of the patients while the fellow eye of patients and HCs did not change much. Furthermore, the AMD patient got a lower MoCA score compared to the HCs. Our results illustrate that the fellow eye of the AMD patient underwent vessel density change, which may lead to the early stage of AMD. The lower score of the MoCA test in AMD patients refers to the cognitive impairment. These findings show the significance of taking actions to prevent the progress of AMD in the fellow eye, as well as paying more attention to the development of cognitive impairment of these patients.