Long-Term Survival of the PermaVision Refractive Implant Under a Lamellar Corneal Flap

Abstract

Abstract: : Purpose: Anamed's PermaVision implant is a new refractive device that is implanted under a lamellar keratectomy flap. It is composed of a proprietary hydrogel material (Nutrapore) that permits the transmission of oxygen and glucose through the body of the device and can correct from plus six to minus six diopters of refractive error. The purpose of this study is to determine the long-term biocompatibility and safety of the PermaVision implant. Methods: Lamellar keratectomies were produces with a microkeratome in 4 eyes of breeder New Zealand White rabbits. PermaVision implants were placed under the lamellar flaps. Slit lamp examinations with photography and confocal microscopy were performed at regular intervals to assess the status of the eye and the implants. After 30 months, the subjects were sacrificed and corneas were obtained for histological examination. Results: The PermaVision implants and LASIK flaps remained in place in all eyes. No flap abnormalities were observed up to 30 months after implantation. The cornea of each rabbit remained clear and no infiltrates developed. Confocal microscopy and standard histological preparations of the corneas revealed no inflammatory stimulation or absorption of the corneal implants. No flap melts or thinning was seen. Conclusion: After 30 months, the PermaVision implants remained in position under the corneal lamellar flap and appeared to be biocompatible in this rabbit model.

Keywords: 544 refractive surgery • 549 refractive surgery: other technologies • 369 cornea: clinical science