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Altered Macular Microvasculature in Mild Cognitive Impairment and Alzheimer Disease
Hong Jiang1, Yantao Wei, Yingying Shi
1Department of Ophthalmology (HJ, YW, YS, GG, FZ, EAV, BLL, JW), Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida; Department of Neurology (HJ, CBW, XS, TR), Evelyn F. McKnight Brain Institute, University of Miami Miller School of Medicine, Miami, Florida; State Key Laboratory of Ophthalmology (YW), Zhongshan Ophthalmic Centre, Sun Yat-sen University, Guangzhou, Guangdong, China; and BioStatistics Center (EAV), Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
Background:
The goal of the present study was to analyze the macular microvacular network in mild cognitive impirment (MCI) and Alzheimer disease (AD).
Methods:
Twelve patients with AD and 19 patients with MCI were recruited together with 21 cognitively normal controls with a similar range of ages. Optical coherence tomography angiography was used to image the retinal microvascular network at the macular region, including retinal vascular network (RVN), superficial vascular plexus (SVP), and deep vascular plexus (DVP). Fractal analysis (box counting, Dbox) representing the microvascular density was performed in different annular zones and quadrantal sectors. The macular ganglion cell-inner plexiform layer (GC-IPL) thickness was measured using Zeiss OCT. The relationship between the retinal microvasculature and clinical manifestations was analyzed.
Results:
Patients with AD had lower densities of RVN, SVP, and DVP in the annulus, from 0.6 to 2.5 mm in diameter (P < 0.05) in comparison with controls. Patients with MCI had lower density of DVP in the superior nasal quadrant (P < 0.05) than that of the controls. There were no significant differences of GC-IPL thickness among groups (P > 0.05). There was a trend of vascular density loss from control to MCI then AD (P < 0.05). Retinal microvascular density of DVP was correlated with GC-IPL thickness (P < 0.05) in patients with AD, but not in patients with MCI and controls.
Conclusions:
Patients with AD had less density of retinal microvascular networks than controls. Our findings suggest the presence of retinal microvascular dysfunction in AD.
Insights
Alzheimer disease (AD) patients show reduced retinal microvascular networks compared to controls. This study suggests retinal microvascular dysfunction may be present in AD.
Area of Science:
- Ophthalmology
- Neurology
- Medical Imaging
Background:
- Mild cognitive impairment (MCI) and Alzheimer disease (AD) are neurodegenerative conditions affecting cognitive function.
- Investigating ocular biomarkers may offer insights into the progression of these diseases.
Purpose of the Study:
- To analyze the macular microvascular network in patients with mild cognitive impairment (MCI) and Alzheimer disease (AD).
- To compare retinal vascular network (RVN), superficial vascular plexus (SVP), and deep vascular plexus (DVP) densities between patient groups and controls.
Main Methods:
- Optical coherence tomography angiography (OCTA) was used to image the macular microvasculature.
- Fractal analysis (box counting) quantified microvascular density in different retinal zones.
- Macular ganglion cell-inner plexiform layer (GC-IPL) thickness was measured.
Main Results:
- Patients with AD exhibited significantly lower densities of RVN, SVP, and DVP compared to controls.
- MCI patients showed reduced DVP density in the superior nasal quadrant compared to controls.
- A trend of decreasing vascular density from controls to MCI to AD was observed.
Conclusions:
- Alzheimer disease is associated with reduced retinal microvascular network density.
- Findings suggest the presence of retinal microvascular dysfunction in AD.