RETINA IMPLANT Alpha AMS in Blind Patients With Retinitis Pigmentosa

This is an interventional treatment trial for Retinitis Pigmentosa focused on measuring Retinitis Pigmentosa, Inherited Retinal Degeneration, Retina Implant, Retinal Prosthesis, Artificial Vision Read More

Inclusion Criteria:

• Blind RP patients with LP or NLP identified in both eyes using a photoflash test.

(NLP inclusion is defined as participants who at screening give less than 9 correct answers out of 20 trials to the photoflash test; LP inclusion is defined as participants who at screening give 9 or more correct answers out of 20 trials to the photoflash test)

• Pseudophakia for at least 3 months prior to entrance into study.
• Central visual function of 12 years / lifetime or greater with a history of reading vision in the eye to be implanted.
• Fluorescein angiography showing retinal vascular perfusion in all four quadrants of macula.
• Fifty (50) years of age or older at time of enrollment.
• Evidence of inner retinal function (ganglion cells and optic nerve function) by EEP test identified by the ability to elicit phosphene thresholds.
• ERG showing rod and cone non-function.
• Willing and able to give written informed consent and participate in ongoing follow-up.

Exclusion Criteria:

• Ophthalmic conditions other than RP with relevant effect upon visual function (e.g., glaucoma, optic neuropathies, trauma, diabetic retinopathy, retinal detachment, macular degeneration, cystoid macular edema, MS) with the addition of tobacco, alcohol abuse and retinotoxic drugs e.g. plaquenil and thorazine.
• Any other ocular disease that affects retina and / or optic nerve function.
• Opacification of ocular structures that prevent clear image transmission.
• Nystagmus.
• Cystoid macular edema within target region for implantation shown via Optical Coherence Tomography (OCT).
• Retina detected as too thin as shown via OCT (<100 μm) to expect required functionality of inner retina and /or OCT shows no layering of the inner retina in the central region.
• Scar tissue (e.g., epiretinal, intraretinal, subretinal, macular pucker) within target region for implantation.
• Heavily clumped pigmentation at posterior pole (would interfere with image transmission to vision chip).
• Anterior segment pathology that interferes with clear visualization of the retina (e.g., presence of cloudy or scarred cornea and / or papillary membrane) that cannot be resolved prior to entrance into study.
• Amblyopia reported earlier in life for eye to be implanted.
• Systemic diseases that might imply considerable risks with regard to the surgical interventions and anesthesia (e.g., cardiovascular / pulmonary diseases, severe metabolic diseases).
• Any condition and / or allergic contraindication to pre-operative, intra-operative, and post-operative medication.
• Health problems where general anesthesia is contraindicated.
• Disease or conditions that would probably limit life expectancy to less than 1 year from screening.
• Orbital deformity that would interfere with surgical implantation that could not be resolved prior to entrance into study.
• Patients with plastic intra-ocular lenses, or other materials, that would interact with silicone oil.
• Women who are pregnant or nursing, or women of childbearing potential who are not willing to use a medically acceptable means of birth control for the duration of the study, or women unwilling to perform a pregnancy test before entering the study.
• Neurological and / or psychiatric diseases (e.g., Parkinson, epilepsy, MS, depression or severe anxiety).
• Lack of cognitive and / or emotional ability (e.g., depression or severe anxiety) limiting participation as assessed by psychiatric evaluation.
• Participation in another interventional clinical trial within the past 30 days.
• The need for regular administration of anticoagulants, platelet aggregation inhibitors or analgesics containing acetylsalicylic acid.
• Disease or conditions that likely require regular use of MRI or other similar imaging technology that emits electromagnetic radiation.
• Patients unwilling to avoid participating in vigorous sports or activities with a high risk of a head injury.
• Patients unwilling to avoid security-scanning devices that would result in a full body, manual search.
• Ability to perceive form or motion under optimal conditions (largest size, brightest lighting, highest contrast, etc.) of form and motion testing as tested by BaLM, BaGA, and Landolt C.
• Patients with hearing deficits and cochlear implants or patients who may be implanted with cochlear implants in the near future.
• Patients undergoing or requiring medical treatments generating induced currents in the area of the implant such as electrosurgery, diathermy, neurostimulation, electroconvulsive therapy, ionizing radiation therapy, therapeutic ultrasound.
• Subjects with no active immunization status against organisms causing meningitis.