Certain choroidal structural parameters may differ between patients who have Alzheimer’s disease (AD), mild cognitive impairment (MCI) and healthy cognition, a recent study suggests.1

This prospective, cross-sectional study evaluated 112 eyes of 67 patients with AD, 143 eyes of 74 patients with MCI and 248 eyes of 137 controls. The researchers used high-definition EDI foveal scans to assesses the patients’ subfoveal choroidal thickness (SFCT), total choroidal area (TCA), luminal area (LA) and choroidal vascularity index (CVI), the last of which being a ratio of the LA over TCA.1,2 Research shows the CVI can provide valuable information about the vascularity of the choroid with less variability and with less influence from physiologic factors than choroidal thickness measures.2

After adjusting for age, sex and visual acuity, the researchers found that both TCA and LA were significantly greater in AD and MCI, while CVI was significantly lower in MCI compared with controls. They added that the SFCT was similar among all patients.1

The researchers emphasize the need for more research on the impact of these choroidal changes in patients along the Alzheimer’s continuum.1

1. Robbins CB, Grewal DS, Thompson AC, et al. Choroidal structural analysis in Alzheimer’s disease, mild cognitive impairment, and healthy cognitively healthy controls. Am J Ophthalmol. October 8, 2020. [Epub ahead of print].

2. Iovino C, Pellegrini M, Bernabei F, et al. Choroidal vascularity index: an in-depth analysis of this novel optical coherence tomography parameter. J Clin Med. 2020 Feb; 9(2): 595.