Abstract
Abstract: :
Purpose: The development of an Intraocular Vision Aid could preserve the vision of people with irreversible opacification and shrinkage of the anterior segment. An implantable LED array, placed in the capsular bag, bridges the opaque cornea and projects an image of the environment onto the intact neuroperceptive retina. To develop such an Intraocular Vision Aid preliminary work comprised the establishment of an appropriate implantation technique, evaluation of the wireless energy and signal transmission of the prosthesis and investigation of the long-term biocompatibility. Methods: Six rabbit eyes underwent an extracapsular lentectomy and implantation of an active LED array embedded in silicone coating. Function of the array was checked daily by using an inductive transmission energy supply. To assure water-impermeability of the silicone embedding the LED arrays were stored in normal saline solution as control and were investigated respectively. After 3 weeks the arrays were explanted and the eyes were processed for histological examination. Results: Due to the volume of the embedded array implantation could only be achieved in the sulcus, where it remained stable and centered. Stable signal transmission and wireless stimulation of the LED array was maintained for three days followed by a slow functional loss of the prosthesis. However, the control group showed the same results. Microscopical analysis disclosed white and black deposits on the electric unit after both procedures. After drying the arrays for another three days electrical function could be restored in all arrays. Histological investigation of the enucleated eye showed only moderate postoperative inflammatory changes in the anterior chamber angle and no alteration in the structures of the retina. Conclusions: Wireless energy and signal transmission towards the implanted LED array can be maintained for several days in rabbit eyes. However, the transient loss of function in the long-term shows the susceptibility of the electric circuit and emphasizes the demand for improved watertight silicone embedding.
Keywords: trauma • keratoprostheses • anterior segment