Transcranial magnetic stimulation as a potential therapeutic tool for preventing blindness
Dr. Jover Eduardo Fernandez (Director of the Biomedical Group of Bioengineering at UHM, Alicante, Spain). Prof. Dr. med. Andrea Cusumano (Tor Vergata University of Rome).
Reversing blindness is nowadays possible thank to novel techniques based on retinal prostheses or stimulation of the occipital cortex, which have proven safe and effective in numerous clinical trials in the last years.
Nevertheless, each of these techniques does have some drawbacks or limitations, the first being restricted to a population of blind patients who still present intact bulbs, internal retina and optic nerve; the second implying an open neurosurgery for the implantation of electrodes, which makes a widespread use of this technique questionable. For this reason, the search for an alternative non-invasive technique able to elicit phosphene perception in the blind is desirable.
The present pilot project aims at testing the possibility of eliciting phosphene and phosphene perception in healthy volunteers and in blind patients with congenital and acquired blindness by using a non-invasive technique known as transcranial magnetic stimulation (TMS), a technique originally introduced as a diagnostic tool in peripheral and central neurology. TMS has shown to have little effect on general body functions and does not cause detectable structural changes, minimizing risks of seizures.
A first step of investigation foresees to test the possibility of eliciting phosphenes in healthy volunteers, in order to assess whether phosphene elicitation is indeed possible and phosphene patterns are perceived as such. Subsequently, the same tests will be repeated in blind individuals, separated into clinically defined subgroups (congenital blindness, acquired blindness). This first step will allow for the assessment of basic parameters of TSM-induced phosphene perception and verify which are the optimal stimulation parameters needed to elicit phosphenes and patterned sensations.
The second step will test the possibility to connect a video camera with the TMS device in order to transfer visual information from the patient’s environment to the brain in daily life conditions.