An interventional study of Minicraniotomy in Blindness, sponsored by Universidad Miguel Hernandez de Elche. Recruiting at 2 sites in Spain. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-05-05.
Sponsored by Universidad Miguel Hernandez de Elche · Not applicable, Interventional, and Other
The objective of this study is to evaluate the usefulness of a cortical visual prosthesis based on intracortical microelectrodes to provide a limited but useful sense of vision to profoundly blind. This pilot study will provide important information on safety and efficacy for the development of an useful cortical visual neuroprosthesis for the blind.
Visual impairment is one of the ten most prevalent disabilities and poses extraordinary challenges to individuals in our society, which is heavily dependent on sight. Drug development and genetic engineering have had only marginal success as possible treatments but new hope has been generated by recent advances in neuroscience, micro-fabrication technologies, biomaterials, neuromorphic engineering and information and communication technologies leading to the development of highly sophisticated neural prosthetic devices which interact with the nervous system. Such assistive devices have already allowed thousands of deaf patients to hear sounds and acquire language abilities and the same hope exists in the field of visual rehabilitation.
Several research groups worldwide are engaged in attempts to restore vision through retinal prosthesis. However these devices are not viable for all causes of blindness. Thus, if the communication link between eye and brain is destroyed (e.g. for Glaucoma or optic nerve atrophy), as is the case for 148 million people worldwide, then visual cortical prosthesis holds the dominant hope for visual restoration. Consequently, there are many compelling reasons to pursue the development of a cortical prosthesis capable of restoring some useful vision in profoundly blind patients and this approach may be the only treatment available for end-stage retinitis pigmentosa patients and for pathologies such as glaucoma optic atrophy, trauma to the retina and/or optic nerves, and for diseases of the central visual pathways due to brain injuries or stroke.
The investigators will implant the CORTIVIS vision neuroprosthetic system, which utilizes a FDA cleared microelectrode array, into blind human volunteers and obtain descriptive feedback about visualized percepts. The experiments are designed to learn if volunteers can learn to integrate the electrical stimulation of brain visual areas into meaningful percepts. It is expected that a cortical device can create truly meaningful visual percepts that can be translated into functional gains such as the recognition, localization and grasping of objects or skillful navigation in familiar an unfamiliar environments resulting in a substantial improvement in the standard of living of blind and visually impaired persons.
All the experiments will be carried out at the patient's hospital room (Hospital IMED Elche) during the post-surgical period or in a human psychophysical laboratory (University Miguel Hernández).
144 studies on the registry are indexed under Blindness; 33 are open to participants now.
This study's planned enrollment of 5 is below the median of 37 across 101 interventional studies indexed under Blindness.
Browse Blindness studies →Universidad Miguel Hernandez de Elche is the lead sponsor of 87 studies on the registry; 16 are open to participants now.
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Special consideration will be given to patients with (1) detailed medical histories, including documentation of the onset, mechanism and evolution of the blindness; (2) lower risks associated with surgery; and (3) no psychiatric disorders or other mental disabilities.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Blind volunteers will be implanted with our existing vision neuroprosthetic system, which utilizes a FDA cleared microelectrode array, using a minicraniotomy. The array will be implanted near the occipital pole or in extra striate areas. The investigators will collect descriptive feedback regarding thresholds, evoked perceptions and stimulation parameters leading to recognizable patterns.
Procedure: Minicraniotomy
The surgical method for the implantation of the intracortical microelectrodes is straightforward and follows the standard neurosurgical procedures. Briefly, after the scalp is prepped with an antiseptic, a small skin incision is made. Then the skin and muscles are lifted off from the bone and folded back. Next, one small burr hole or a minicraniotomy of approximately 1.5 cm is made in the skull. This is a minimally invasive procedure that allows an easy access to the brain and is a standard procedure widely used in neurosurgery.
Thresholds of visual perceptions elicited by intracortical microstimulation
Charges needed for eliciting visual perceptions through electrical stimulation of the human cortex
Time frame: Within implantation period (up to 6 months)
Phosphene mapping
Location of induced perceptions within the visual field by pointing with the finger where the phosphene is perceived
Time frame: Within implantation period (up to 6 months)
Visual Acuity
Spatial resolution measured by computerized visual tests
Time frame: Within implantation period (up to 6 months)
Motion perception
Correct perception of movement with a coarse pattern moving in one of four directions
Time frame: Within implantation period (up to 6 months)
Visual function
Effectiveness of intracortical microstimulation to recognize letters, habitual objects and complex stimulation patterrns as measured by a suite of visual function tests. Questionnaire.
Time frame: Within implantation period (up to 6 months)
Number of participants with significant adverse events.
Complications and adverse events will be assessed through participant description of any possible adverse event, neurological examination, clinical tests and a specific questionnaire.
Time frame: Within implantation period (up to 6 months)
Plan to share: No
Started Oct 2019 (actual). Primary completion is estimated for Dec 2027, 98 months after the start.
Of 36 interventional studies with no phase under Blindness, half reached primary completion within 57 months of starting (the median), counting those still running; a quarter within 19. This study's planned 98 months is above that.
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Universidad Miguel Hernandez de Elche