Choroidal Thickness in Patients with Mild Cognitive Impairment and Alzheimer’s Type Dementia

Abstract

Aim. To asses both choroidal thickness differences among Alzheimer's type dementia (ATD) patients, mild cognitive impairment (MCI) patients, and healthy control (C) subjects and choroidal thickness relationships with cognitive performance. Methods. A total of 246 eyes of 123 people (41 ATD, 38 MCI, and 44 healthy C subjects) were included in this study. Complete ophthalmological and neurological examination was performed in all subjects. Choroidal thicknesses (CT) were measured at seven locations: the fovea, 500-1500-3000 μm temporal and 500-1500-3000 μm nasal to the fovea by enhanced depth imaging optical coherence tomography (EDI-OCT). Detailed neurological examination including mini mental state examination (MMSE) test which evaluates the cognitive function was applied to all participants. Results. The ages and genders of all participants were similar in all groups. Compared with healthy C subjects, the CT measurements at all regions were significantly thinner both in patients with ATD and in patients with MCI than in healthy C subjects (p < 0.05). The MMSE scores were significantly different among ATD patients, MCI patients, and healthy C subjects. They were 19.3 ± 1.8, 24.8 ± 0.9, and 27.6 ± 1.2 in ATD, MCI, and healthy controls, respectively (p < 0.001). There were also significant correlation between MMSE score and choroidal thickness at each location (p < 0.05). Conclusions. CT was reduced in ATD patients and MCI patients. Since vascular structures were affected in ATD patients and MCI patients, they had thin CT. Besides CT was correlated with degree of cognitive impairment. Therefore CT may be a new biomarker in diagnosis and follow-up of MCI and ATD patients.

Evaluation of optical coherence tomography angiographic findings in Alzheimer’s type dementia

“…The correlation we found between the retinal vascular density and FAZ measurement zones and MMSE scores is the first one in the literature in this area. Moreover, we found a correlation between the CT value and MMSE score in a previous study similar to this present one23; another study conducted on this subject did not find any correlation 24…”

Alzheimer’s disease: A review of its visual system neuropathology. Optical coherence tomography—a potential role as a study tool in vivo

“…Figure 3 depicts these changes in choroidal thickness. These findings have been corroborated by further studies [62,63]. One study also included patients with MCI, and observed reduced CT in this group, although no statistically significant differences between the MCI and AD patient groups were found [63].…”

“…These findings have been corroborated by further studies [62,63]. One study also included patients with MCI, and observed reduced CT in this group, although no statistically significant differences between the MCI and AD patient groups were found [63]. Although CT is reduced, it remains to be elucidated whether or not choroidal thinning is correlated with MMSE scores, as authors report conflicting results.…”

“…More recent OCT studies have reported also macular changes in the ganglion cell complex (GCC), comprising the ganglion cell layer (GCL) and inner plexiform layer (IPL). Also, choroidal thickness [60] has been shown to be reduced in patients with AD, as measured by EDI-OCT Spectralis Heidelberg [61][62][63].…”

Response to: Comment on “Choroidal Thickness in Patients with Mild Cognitive Impairment and Alzheimer’s Type Dementia”

“…Therefore, we suggested that CT value could be used as a new biomarker in early diagnosis of ATD and MCI patients and follow-up of their progression [1]. …”