A study of living response to artificially synthesized hydroxyapatite implant in the rabbit orbit

: We implanted artificially synthesized hydroxyapatite (a-HA) spheres into the orbits of sixteen rabbits after enucleation. The spheres were removed 1, 2, 3, and 6 months after implantation and examined by light and scanning electron microscopy. Tissue breakdown and exposure of a-HA implants were not observed in any case. As time passed, fibrovascular tissue gradually invaded the pores of the HA spheres deeper and deeper. Although the HA used was completely artificially, we observed a mild foreign body reaction around the a-HA sphere. HA spheres are appropriate for orbital implants after enucleation without scleral enveloping.