Clinical Results of Hydroxyapatite Orbital Implantations using Autologous Sclera as a Wrapping Material

PURPOSE: To evaluate the clinical result of hydroxyapatite implantation using autologous sclera as wrapping material. METHODS: From December 2001 to February 2003, we performed 20 cases of hydroxyapatite implantation with autologous sclera as wrapping material. Eyes were enucleated for severe phthisis because evisceration could not provide adequate space for hydroxyapatite implantation or secondary hydroxyapatite implantation after prior evisceration. Postoperative complications were evaluated at postoperative 1 week, 2 weeks, 3 weeks - 1 month, 2 months, 3 months, and every 2 or 3 months thereafter. RESULTS: The mean follow up period was 12.1 +/- 4.52 months (4~18 months). During the follow up period, conjunctival erosions developed in 2 cases, which were controlled by conservative management only. No such postoperative complications as implant exposure, orbital infection, extrusion, inflammatory reaction occured. CONCLUSIONS: Autologous sclera is the suitable wrapping material of hydroxyapatite implant when enucleation is needed in primary surgery for severe phthisis, or for secondary hydroxyapatite implantation after prior evisceration surgery.

Hydrox yapatite Implantation with Scleral Patch Graft in Eviseration

When inserting an orbital implant, evisceration allows suitable movement of the eyeball making it a better method cosmetically than enucleation; performing hydroxyapatite implantation after evisceration preserving the cornea sometimes causes the complication of cornea melting. To reduce complications after evisceration and hydroxyapatite implantation,scleral patch graft with corneal excision was performed in 15 eyes of 15 patients. In all 15 eyes, 20 mm-sized hydroxyapatite implants were inserted. Fourteen eyesshowed no complications, but in one eye scleral suture was exposed and 2months later the implant was exposed around that area. Also, there developed conjunctival wound dehiscence and exposure of the central portion of the scleral graft in two eyes. But the exposed sclera was fibrovascularized by the surrounding conjunctival tissue and did not lead to exposure of the implant. This study suggests that when performing evisceration and hydroxyapatite implantation, scleral pach graft with cornea excision is helpful in reducing the incidence of exposure of hydroxyapatite implant.

Clinical Experiences of Hydroxyapatite Implant

The hydroxyapatite has been used as an orbital implant for reconstruction after enucleation or evisceration. It has been known to be a biocompatible and nontoxic implant with good fibrovascular ingrowth, few postoperative complications, excellent prosthesis motility, and good cosmesis. We performed 36 cases of hydroxyapatite implantation with enucleation or evisceration from July 1992 to August 1994. The mean follow-up period was 7.4 months(range, 4 to 13 months). There were nine cases of implant exposure. three cases of peg extrusion, three cases of superficial conjunctival wound dehiscence, and one case of granulation tissue overgrowth. There was no infection of implant. Improving the postoperative results and reducing the postoperative complications, it requires proper surgical techniques including the selection of adequate implant size and good doctor-patient relationship.