Abstract
Purpose: :
To evaluate the safety of the first wireless Retinal Implant System in blind patients with retinitis pigmentosa. A specific objective was to test how the implant is tolerated by the eye over time.
Methods: :
In a prospective study, 4 subjects with a visual acuity of light localization or less received an epiretinal implant. The postoperative follow-up was 18 months. ICG, fluorescein angiograms and OCT investigations were performed on predefined follow-up investigations. Angiograms and OCT were examined and compared looking for changes in tissue integrity or damage caused by the implant. OCT data were obtained measuring the distance between retina and electrode array as well as retinal thickness.
Results: :
Fluorescein angiograms showed no signs of vascular leackage or tissue proliferation on the implant. Angiograms and fundus photographs revealed only a minimal change of vessel configuration and array position over time in two cases. OCT data proved a close proximity between the retina and the electrode film. In one case OCT scans showed a transient retinal edema. No retinal tissue damage was observed.
Conclusions: :
ICG, fluorescein and fundus photographs document only a minor change in the position of the implanted electrode array. OCT images prove, that no injury was caused by the implant to the underlying retina. In most of the OCT recordings the intraocular part of the implant was observed as being well positioned within the eye. This fact is also indicated by the stability of threshold levels necessary for stimulation. These results verify the safety of the implant, its stable fixation and the good toleration of the implant by the eye.
Clinical Trial: :
http://www.aekhh.de/diekammer/ethikkom.htm 2447
Keywords: clinical (human) or epidemiologic studies: systems/equipment/techniques • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retinal degenerations: hereditary