Advanced Perimetry for the Evaluation of Neuroplasticity in the Visual Cortex

Various studies report evidence that neuroplasticity can be induced and supported by training the affected visual areas of the human and non-human brain. Other studies contradict this approach, explaining the primary improvements in the visual field through inadequate eye fixation control during examinations. Therefore, whether neuropsychological training after a stroke or trauma actually improves the visual field loss remains controversial. The question of neuroplasticity after stroke or trauma is controversially discussed in brain research, which simultaneously affects the accuracy of diagnosis in practice and additionally the clinical treatment course of affected patients. For this reason, we have developed a novel procedure for visual field diagnostics, which significantly improves diagnostics and thus can answer the question of the neuroplasticity of the human brain. Initial preliminary studies already show that the newly developed instrument is indeed superior to established instruments used for evaluating neuroplasticity through visual field diagnostics. We are convinced that our diagnostic instrument, which combines technology from eye-tracking and virtual reality hardware, represents both a highly accurate and practical method to make reliable statements about the visual field of patients. As part of the present project proposal, we will first integrate the measuring instrument into VR hardware and conduct a study demonstrating the accuracy and reliability of the paradigm. In a second step, patients will be examined using the measuring instrument, enabling statements about the effectiveness of neuropsychological training, which in turn allows conclusions about the functionality of neuroplasticity. Based on these findings, we are convinced that we will gain well-founded scientific insights into the existence of the regenerative capacity of visual areas in the human brain.

In an increasingly aging society, the accurate diagnosis and efficient treatment of neuropsychological disorders are becoming more significant. The project developed a precise and objective instrument for diagnosing visual field defects, which are often the result of a stroke. This diagnostic instrument subsequently allowed us to investigate the efficiency of a treatment method - Visual Restitution Training - with previously unattainable accuracy and objectivity. The principle of the training is based on the repeated stimulation of remaining healthy brain cells between the healthy and damaged parts of the visual cortex. This should lead to a gradual enlargement of the healthy part of the visual cortex and consequently to a larger visual field. We implemented the stimulation using a virtual reality device that patients could wear on their heads. The device allowed patients to train at any place and at any time. The patients trained daily for 30 minutes over a period of about 6 months. Despite the intensity and long duration of the training and the outstanding commitment of the patients, the training proved to be ineffective. This is an important finding because it can prevent patients from spending time and monetary resources on an inefficient treatment in the future. A chance finding of the project was that patients who do not suffer from cortical blindness but from visual neglect (a disorder of visual attention) might benefit from visual restitution training. Additionally, the implementation of neuropsychological interventions in virtual reality proved to be promising for the future.