June 2013
Volume 54, Issue 15
Free
ARVO Annual Meeting Abstract  |   June 2013
MRI Brain Scan in Argus II Retinal Prosthesis Patients
Author Affiliations & Notes
  • Yvonne Luo
    National Institute of Health Research, Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom
    Institute of Ophthalmology, University College London, London, United Kingdom
  • Indran Davagnanam
    Brain Repair & Rehabilitation Unit, Institute of Neurology, University College London, London, United Kingdom
  • Lyndon daCruz
    Vitreoretinal Service, Moorfields Eye Hospital, London, United Kingdom
    National Institute of Health Research, Biomedical Research Centre, Moorfields Eye Hospital, London, United Kingdom
  • Footnotes
    Commercial Relationships Yvonne Luo, None; Indran Davagnanam, None; Lyndon daCruz, Second Sight Medical products Inc. (R)
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2013, Vol.54, 1051. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Yvonne Luo, Indran Davagnanam, Lyndon daCruz; MRI Brain Scan in Argus II Retinal Prosthesis Patients. Invest. Ophthalmol. Vis. Sci. 2013;54(15):1051.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract
 
Purpose
 

To report the safety and feasibility of MRI brain scanning on 2 blind retinitis pigmentosa patients fitted with Argus II retinal implant for prosthetic vision. To our knowledge, these are the first two patients ever to undergo MRI brain scan in the presence of Argus II device. Being commercially available in Europe and with recent FDA recommendation for marketing approval, it is foreseeable that clinicians will encounter more and more patients with Argus II implants in the near future.

 
Methods
 

Two Argus II retinal prosthesis patients underwent MRI brain scans at 1.5 Tesla field strength for investigations of unrelated medical conditions. Changes in implant position are assessed by comparing color fundus photographs and OCT scans of the implant taken before and after MRI. Changes in implant function are assessed by comparing the impedances and thresholds of the 60 electrodes. Artifacts produced by the implant on MRI image are estimated. The subjects have been followed-up for 3 months and 15 months respectively and ongoing to report any adverse event.

 
Results
 

Visual and quantitative comparison of the fundus photographs and OCT images respectively did not show any positional change of the implant in both patients. The frequency distributions of impedance readings for both implants are comparable before and after MRI indicating no significant change in retinal contact. Some deterioration in electrode thresholds are noted for both patients, but these are no greater than the general trend of threshold deterioration with time observed due to disease progression. The implant produces local moderate artifacts of up to 29mm x 37mm x 40mm (AP x TR x SI) which preclude visualization of intra-orbital contents immediately adjacent to the implant, but interpretation of other orbital and retro-orbital structures are possible. There is no adverse event e.g. implant dislocation, retinal detachment during the follow-up.

 
Conclusions
 

MRI brain scans have been performed on 2 patients fitted with Argus II retinal prosthesis to date with no adverse effect on patient safety and implant function. The implant produces a moderate size artifact on MRI to preclude visualization of intra-orbital contents, but interpretations of adjacent structures are reasonable.

  
Keywords: 689 retina: distal (photoreceptors, horizontal cells, bipolar cells) • 465 clinical (human) or epidemiologic studies: systems/equipment/techniques • 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)  
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×