Abstract
Purpose :
The electronic keratoprosthesis (or intraocular projector) is a novel approach for restoring vision in patients with intractable corneal blindness. It consists of a crystalline lens sized powered implant fixated behind the iris which projects light directly onto the macula. However, no intraocular implants of such a design have previously been implanted. We seek to evaluate feasibility and safety of different fixation techniques for this type of implant.
Methods :
Three functional prototypes were produced. We evaluated three different fixation techniques in 3 living pigs. The first consisted of loops for suture fixation, the second haptic without suture fixation and lastly channel for suture passage. Loops were approximately 1 mm in size, and constructed of 5-0 Prolene suture material and adhered to the device housing using biocompatible adhesive. The haptics were also made of 5-0 Prolene material, and were approximately 5 mm in length. The channels were developed as an integral part of the 3D printed device housing, one at each corner of the bottom part (figure 1). During the surgery a partial open sky 8 mm trephination was used to insert the implant into the eye, then the respective fixation techniques were used. The open sky incision was closed at the end of surgery (figure 2) and the pigs were maintained for 3 months after implantation.
Results :
The passage of sutures through the sclera in the loop design required extensive tissue manipulation, resulted in large amounts of intraocular hemorrhage and required a longer duration of the surgery and was found to be less than ideal. Both the haptic and channel design were able to accomplish in an expedient manner with minimal hemorrhage and remained stable over three months. All three devices remained functional at three months.
Conclusions :
We here developed and tested three techniques for fixation of intraocular electronic devices in the mid vitreous in three pigs over three months. This is the first study of fixation of intraocular electronics which can provide a new means of vision restoration.
This is a 2020 ARVO Annual Meeting abstract.