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

Mehmet Bulut,Fatma Kurtuluş,Devrim Toslak,Aylin Yaman,Muhammet Kazim Erol,Deniz Turgut Çoban,Berna Doğan,Ebru Kaya Başar

doi:10.1155/2016/7291257

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.

Highlights

Alzheimer’s type dementia disease (ATD) is the most frequent form of dementia and is characterized by cognitive deficits including progressive memory disturbance, higher cortical functions, executive functions, and other components of cognition [1]
ATD is primarily a disease of the brain characterized by cognitive abnormalities, it is associated with impairments in visual function, including impairments in color perception, depth perception, contrast sensitivity, and visual field [4]
41 Alzheimer’s type dementia (ATD) patients, 38 Mild cognitive impairment (MCI) patients, and 44 cognitively healthy age-matched volunteers were enrolled in this study

Summary

Introduction

Alzheimer’s type dementia disease (ATD) is the most frequent form of dementia and is characterized by cognitive deficits including progressive memory disturbance, higher cortical functions, executive functions, and other components of cognition [1]. Mild cognitive impairment (MCI) is a recently described syndrome in which patients experience subjective and objective memory deficits or have impairment of other cognitive abilities other than memory They may yield abnormal scores on memory tests, but their activities of daily living and occupational functions are not affected. Clinical studies have indicated that vascular changes play an important role early in ATD pathogenesis, though cerebral amyloid beta (Aβ) plaques and neurodegeneration are the main hallmarks of the disease [9, 10]. Both retinal and choroidal vascular Aβ deposits have been observed in animal models of ATD [11]. To fill this research gap, this study measured CT in MCI and ATD patients using enhanced depth imaging optical coherence tomography (EDI-OCT) and compared their CT values to those of healthy controls

Materials and Methods

Results

Discussion