Evaluation of choroidal thickness in prodromal Alzheimer’s disease defined by amyloid PET

Abstract

Objective To assess and compare the involvement of choroidal thickness (CT) in patients with mild cognitive impairment (MCI) and dementia due to Alzheimer's disease (AD) defined by amyloid PET and healthy controls (HC). Methods Sixty-three eyes from 34 AD patients [12 eyes (19.0%) with dementia and 51 eyes (80.9%) with MCI], positive to 11 C-labelled Pittsburgh Compound-B with positron emission tomography (11 C-PiB PET/CT), and the same number of sex-and age-paired HC were recruited. All participants underwent enhanced depth imaging optical coherence tomography (EDI-OCT) assessing CT at 14 measurements from 2 B-scans. Paired Student t-test was used to compare CT measurements between MCI, dementia and sex-and age-paired HC. A univariate generalized estimating equations model (GEE) test was performed to compare MCI and dementia individually with all HC included. Results Compared with HC, eyes from patients with positive 11 C-PiB PET/CT showed a significant CT thinning in 5 selected locations (in foveal thickness in vertical scan, in temporal scan at 1500μm, in superior scan at 500μm and in inferior scan at 1000μm and 1500μm, p = 0.020-0.045) whilst few significant CT reduction data was reported in MCI or dementia individually versus HC. However, the GEE test identified significant CT thinning in AD compared with all HC included (p = 0.015-0.046).

Foveal Avascular Zone and Choroidal Thickness Are Decreased in Subjects with Hard Drusen and without High Genetic Risk of Developing Alzheimer’s Disease

“…A decrease in choroidal thickness has been reported in patients with AD compared with healthy older subjects [15,33,34,[45][46][47][48][49]. These changes have also been observed in early stages of the disease [32], including in patients with preclinical and prodromal AD [49] and those with mild cognitive impairment (MCI) [41].…”

“…A decrease in choroidal thickness has been reported in patients with AD compared with healthy older subjects [15,33,34,[45][46][47][48][49]. These changes have also been observed in early stages of the disease [32], including in patients with preclinical and prodromal AD [49] and those with mild cognitive impairment (MCI) [41]. Choroidal thinning may indicate abnormal choroidal blood supply associated with hypoperfusion or atrophic changes related to various pathological events, with cerebral Aβ accumulation being the main trigger [33].…”

Retinal Neurodegeneration Measured With Optical Coherence Tomography and Neuroimaging in Alzheimer Disease: A Systematic Review

“…Lee et al (41) measured brain cortical thickness and Aβ deposition but did not find any relationship with retinal parameters. On the other hand, López-de-Eguileta et al (4) used PET to demonstrate macular and choroidal (10) thinning related to the positivity of PiB in patients with AD and MCI.…”

Ocular biomarkers and their role in the early diagnosis of neurocognitive disorders

“…They associated these findings with increased vascularity in the stromal vascular layer. 107 Patients with MCI had also significantly thinner choroid compared to controls according to Bulut et al 108 Conversely, recently Eguileta et al 109 found no significant reduction in the CT. Another study analyzed several choroidal structural parameters, namely the subfoveal choroidal thickness (SFCT), the total choroidal area (TCA), the luminal area (LA) and the choroidal vascularity index (CVI), in patients with AD, MCI, and healthy subjects. They found a higher TCA and LA in the AD and MCI group, whereas CVI was lower in MCI.…”