Eye movement lab

Our focus is to measure and understand the mechanisms involved in eye movements and how the central nervous system is involved in processing visual input and controlling the eye movements. 

Techniques

Electro encephalography - EEG 

Electro encephalography (EEG) derives cortical potentials through electrodes placed on the patients head. We use it to measure intrinsic cortical oscillations and changes in cortical neuronal firing patterns due to visual stimuli presented to the patient. 

Visual evoked potentials - VEP

Visual evoked potentials (VEP) are specific changes in the neuronal firing patterns acquired by an EEG over the occipital region. They represent the response of the visual cortex to visual stimuli. We typically use a checkerboard whose colors flip from black to white and vice versa every other second. VEP is typically used in the clinical context to find characteristic alterations in latencies and amplitudes associated with pathologies of the visual pathway. We use it for basic research of the visual pathway functionality. 

Image 1. Typical configuration of a visual evoked potential using an inverting checkerboard as stimulus.

Eyetracking

We use Eyetracking systems based on camera images of the eye to quantify eye movements. We assess the capabilities of many commercially available Eyetracking systems from budget to high-end solutions, as there are often difficulties in accurate tracking of patients with eye diseases. These systems either are stationary using a camera and a TV or mobile using virtual reality headsets with built in cameras. We perform basic research experiments based on Eyetracking as well as implementing examinations for daily clinical use and comparing these to existing gold standards in eye examination. 

Ophthalmology Publications

Prof. Dr. Dr. Mathias Abegg PubMed