Abstract
Purpose::
To develop an implantable micro-camera for visual prosthesis and to evaluate the feasibility in vivo on rabbit model.
Methods::
An implantable micro-camera was developed for visual prosthesis, which was consisted of the optical lenses (f=2.6mm), CMOS sensor (OmniVision Technologies, Inc., pixel size 5.6 µm*5.6 µm), the cable (length= 100mm, width=1.5mm) and the connector. The raw data can be transmitted to the processor through the connector. The micro-camera was shaped to fit the rabbit lens capsule and encapsulated with the biocompatible silicone. To evaluate the biocompatibility of this device in vivo, the micro-camera was implanted following the surgical extraction of rabbit’s lens similar to cataract surgery procedure. The image of the extraocular targets (human face, letter and resolution chart) in different distances were acquired and compared before and after the implantation. Post operative examinations such as slit lamp observation, intraocular pressure were followed daily. Histological evaluation and corneal endothelial count were performed after 1 month follow-up.
Results::
The micro-camera was 8mm in width and 4mm in thickness after biocompatible encapsulation. The depth of field was from 0.15m to . The frame rate of this micro-camera was 30 frames per second which was suitable for vision task. The encapsulated micro-camera can be positioned stably in the crystalline capsule of the rabbit’s eye. The acquired images had enough resolution for the creation of visual signal because at most 32*32 micro-electrodes were frequently used at present. Visual signal can be created based on the processed image data. The biocompatibility and possible ocular lesions were reported later.
Conclusions::
The feasibility of the implantable micro-camera for visual prosthesis was demonstrated. And the long-term biocompatibility of the device will be discussed.
Keywords: intraocular lens • anterior chamber • image processing