Optical coherence tomography with angiography in the diagnosis of Alzheimer’s disease

BACKGROUND: Alzheimer’s disease is becoming increasingly common and the number of patients with dementia is steadily increasing. Existing diagnostic methods (neuropsychological testing, cerebrospinal fluid examination, magnetic resonance imaging, and positron emission tomography) are either subjective, inaccessible or invasive and expensive, therefore the search for new methods of Alzheimer’s disease diagnosis is necessary. The retina and the human brain share a common embryonic origin. The use of optical coherence tomography with angiography can help in the diagnosis of the disease, especially at an early stage.

AIM: To perform a comparative analysis of the vascular density of the peripapillary region of the human retina with the severity of cognitive impairment and atrophic changes according to MRI in patients with Alzheimer’s disease.

MATERIALS AND METHODS: Thirty patients participated in the study: 20 with Alzheimer’s disease and 10 in the control group. All patients underwent collection of complaints and history, general neurological and ophthalmological examination to evaluate inclusion and noninclusion criteria. Subsequently, neuropsychological testing, magnetic resonance imaging of the brain with assessment according to standardized neuroimaging scales, and optical coherence tomography with angiography according to a standard protocol were performed. The results were processed using the Statistica 10 software package (StatSoft, USA).

RESULTS: Assessment of retinal microvascular bed condition in Alzheimer’s disease patients revealed a significant level of relative vascular density reduction in the upper half of radial peripapillary plexus of the retina due to reduction of small vessel density (p = 0.02). There was a direct correlation between the severity of the decrease in the FCSRT total score and changes in vascular density in the nasal sector of the retina (r = 0.52). There was a significant inverse relationship between vascular density in the temporal sector and the final GCA score for patients with Alzheimer’s disease (r = 0.57). The Fazekas scale score revealed an inverse correlation between its score and the vascular density in the upper retinal half and its upper sector (r = 0.53).

CONCLUSION: Оptical coherence tomography with angiography is a highly informative and promising method for early, including pre-diagnosis of Alzheimer’s disease, which is considerably more accessible and accurate than other techniques.