Abstract
Introduction: Alzheimer disease (AD) as the most common cause of dementia, is affecting approximately 3-40 % of the elderly population and its incidence grows. It is a great burden for healthcare system.
Standard diagnostic neurocognitive examination is time consuming and quite expensive. Therefore there is need for fast and accurate screening test.
The retina of the eye is embryologically extension of the brain so it is assumed that there is correlation between status of the retina detected by optical coherence tomography and cognitive function. The aim of this study is to create a systematic review of studies which analysed correlation betwen retinal nerve fiber layer thickness (RNFL) and cognitive functions in patients with Alzheimer disease.
Methods: Relevant studies from PubMed and Google scholar were searched using key words: Optical coherence tomography, dementia, retinal nerve fibre layer, cognitive function. Only results of studies where RNFL was measured with OCT scan and their association with Alzheimer disease were then analysed.
Results: There were 16 studies eligible for the analysis. Most studies consistently proved association between RNFL thickness at the OCT and the presence of Alzheimer disease.
In nearly every available study there is thinning of RNFL in superior and inferior quadrants, while in nasal and temporal quadrants there was no significant thinning present. Conclusion: So far as the results are being reviewed, there is an evidence that patients with Alzheimer disease have their retinal nerve fibre layer thickness decreased.
This finding could lead to faster diagnosis of this disease and better therapeutical approach in this group of patients. There is sought for other studies with larger cohort and with modern imaging devices and software.