Abstract
Purpose :
Patients with Alzheimer’s disease (AD) demonstrate decreasing retinal capillary densities in the superficial and deep vascular layers compared to controls using Optical coherence tomography angiography (OCT-A). We investigated whether these retinal capillary abnormalities correlate with cognitive impairment and neurodegeneration in mild AD.
Methods :
Fifteen eligible mild AD patients (24 eyes) and 28 healthy controls (34 eyes) with comparable age range were enrolled in this prospective, observational study. Optical coherence tomography equipped with angiography (OCT-A) was used to image the macular capillary network and structure. The capillary densities of the superficial and deep retinal capillary plexus were quantified using custom software. In addition, three-dimensional intraretinal thickness maps were measured with automatically segmentation algorithm. Magnetic resonance imaging (MRI) was used to examine the brain and cognitive testing. The Schelten scale was used to assess visually medial temporal lobe atrophy (MTA) scores (0-4) in all subjects.
Results :
Macular capillary densities of superficial and deep retinal capillary layers in mild AD were reduced compared with controls (P < 0.05).Statistical analysis indicated that lower macular capillary density correlated with the larger MTA score, which reflects the cognitive performance(r=-0.861, P<0.001). Additionally, lower macular capillary density was correlated with thinner RNFL which reflects the neurodegeneration (r=0.639, P=0.002).
Conclusions :
Our results demonstrate the significant correlations of decreased retinal capillary density with thinner RNFL and larger MTA score in mild AD patients. Our findings suggest that retinal capillary abnormality may play an important role in the neurodegeneration and cognitive impairment in early stage of AD.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.