Methods based on eye tracking to assess cognitive impairment

Eye movements have been shown to be altered in neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), Multiple sclerosis (MS) etc. This has prompted researchers to explore potential links between the altered ocular motility observed and the potential impact on eye movements of individuals. Besides common neurological disorders, another emerging concern of cognitive health is the COVID-19 pandemic. Once the main urgency of the pandemic has finished, the long-term impact of the disease has raised and, in fact, patients with the post-COVID-19 condition (PCC) report a broad spectrum of symptoms, including cognitive impairment. Hence, eye movements might be used as a new biomarker for the assessment of cognition impairment, in particular in PCC patients. The most accurate and precise way to monitor eye movements is the eye tracking technology, which allows researchers to monitor and record the eyes position. More recently, the development of mobile and remote eye tracking devices has made possible the collection of data from larger and more diverse samples. In addition, eye tracking is a non-invasive technology and therefore, it is expected to be useful in a clinical environment, although some limitations of the current state-of-the-art systems must be still overcome. Several commercial eye trackers are currently available and they offer different features in functioning, software and hardware configurations. Most eye trackers are used now in laboratory conditions and it is a challenging task to stablish measurement protocols and configurations for clinical purposes, especially for neurological disorders. In view of all this, the aim of this thesis is to develop new methods based on eye tracking technology to assess ocular motility with the ultimate goal of analysing the patient's cognitive status. The technology developed will be integrated into forthcoming clinical studies and specific visual tasks for the analysis of eye movements in patients with cognitive impairment will be designed, with the goal of identifying useful biomarkers for its early diagnosis. In particular, a special emphasis will be on post-COVID-19 patients although other neurological disorders will also be analysed.