REPAIR OF THE ANOPHTHALMIC CAVITY OF RATS WITH SYNTHETIC HYDROXYAPATITE

We placed spheres of synthetic hydroxyapatite (calcium chloride combin ed with sodium phosphate) in the eviscerated or enucleated orbital cav ity of rats in order to evaluate the biocompatibility of this material with the orbital cavity. The study was conducted on 50 albino rats, 2 5 of which were submitted to enucleation and 25 to evisceration of one eye. The animals were sacrificed 7, 15, 21, 30 and 60 days after surg ery and the orbital content was submitted to histopathological examina tion. A reaction of the young granulation tissue type was observed fir st. The hydroxyapatite was gradually surrounded by a granulomatous mac rophage inflammatory response and covered with dense connective tissue that formed a sort of ''mesh'' septating and supporting progressively smaller blocks of the substance. The same type of reaction was observ ed in the enucleated and eviscerated cavities. We conclude that synthe tic hydroxyapatite is an inert nonallergenic material which is appropr iate for volume replacement in the anophthalmic cavity.