Postmortem investigation of a human cortical visual prosthesis that was implanted for 36 years.

Objective: Postmortem analysis of the brain from a blind human subject who had a cortical visual prosthesis implanted for 36 years (Dobelle 2000 Asaio J. 46 3–9)

Approach: This provided insight into the design requirements for a successful human cortical visual prosthesis by revealing, (a) unexpected rotation of the electrode array 25 to 40 degrees away from the midsagittal plane, thought to be due to the torque of the connecting cable, (b) degradation of the platinum electrodes, and (c) only partial coverage of the primary visual cortex by the rectangular array. The electrode array only overlapped with the anterior 45% of primary visual cortex (identified by the line of Gennari), largely missing the posterior foveal representation of visual cortex.

Perspectives of optic nerve prostheses.

A number of projects exist that are investigating the ability to restore visual percepts for individuals who are blind through a visual prosthesis. While many projects have reported the results from a technical basis, very little exists in the professional literature on the human experience of visual implant technology. The current study uses an ethnographic methodological approach to document the experiences of the research participants and study personnel of a optic nerve vision prosthesis project in Brussels, Belgium.

Responses of potential users to the intracortical visual prosthesis: final themes from the analysis of focus group data.

Although visual implant prosthesis projects are advancing, little exists in the literature on the factors that would lead an individual to volunteer for such an experimental procedure. Many ethical issues are raised in recruiting and involving individuals in experimental implant procedures, most involving autonomy and informed consent. This report provides perspectives of 30 totally or legally blind older individuals on their expectations about a potential visual implant, their motivations for volunteering, and the processes they would use for decision making.

Looking ahead: planning for the first human intracortical visual prosthesis by using pilot data from focus groups of potential users.

In planning for our research team's first human implant of a technologically advanced intracortical visual prosthesis we have conducted three focus groups with blind persons from a pool of likely participants. Guided by the principles of the Independent Living movement and Participatory Action Research (PAR), we asked the participants to share their thoughts and concerns about the procedure. The preliminary results reveal that achievement of the desired highest ethical of informed consent will require extensive pre-operative learning opportunities, such as those provided by these focus groups.