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

Abstract

Background/aims: To identify the retinal vascular pathologies in patients with Alzheimer's type dementia (ATD) through optical coherence tomography angiography (OCTA) imaging.

Methods: Our study included 26 patients in the patient group, and age-matched and sex-matched 26 subjects in the control group. A detailed ophthalmological and neurological examination was performed for all subjects included in the study. The retinal, choroidal vascular structures and choroidal thickness (CT) of all subjects were analysed in a detailed way with a commercial spectral domain OCTA. Moreover, all participants underwent detailed neurological examination including Mini Mental State Examination (MMSE) test to evaluate cognitive function.

Results: In the group of patients with ATD, the MMSE score was significantly lower than that of the control group (p<0.001). The retinal vascular density was significantly lower than that of the control group in all zones (p<0.05). Foveal avascular zone (FAZ) was significantly enlarged compared with the control group (p=0.001). CT was significantly lower in the group of patients with ATD (p<0.001). Outer retinal and choroidal flow rates were lower in the group of patients with ATD, while the difference was not significant (p>0.05). Furthermore, significant correlation was found between the MMSE and all vascular density parameters, CT parameter and FAZ tested with OCTA imaging (p<0.05).

Conclusions: In patients with ATD, retinal and choroidal vascular pathologies detected through OCTA imaging can be used as a new biomarker in the early diagnosis of the disease, follow-up of its progression and in investigating the efficacy of the drugs.

Keywords: diagnostic tests/Investigation; imaging; macula; public health; retina.