In one study of over 50 patients who received Bio-eye hydroxyapatite (HA) orbital implants (Dutton 1991), there were no reported cases of migration, extrusion, or unusual orbital inflammatory reactions, and only minimal complications were reported. These complications included: two patients showing granulation tissue in the peg hole, one patient with conjunctiva growing over the peg, and two cases of a misaligned peg. All complications were corrected in the standard fashion and no further complications were reported. Since this initial study, another 100 patients have been implanted with no significant complications and no cases of migration or extrusion (Arora 1992).
In another study of 141 patients, there were no reported adverse reactions to the hydroxyapatite material of the Bio-eye HA implant, and there were no reported complications to the surgical procedure attributable to the hydroxyapatite material (Perry 1991b). One case of postoperative infection and eight cases of exposure were reported. The case of infection was attributed to the surgical procedure. One case of exposure was attributed to a poorly vascularized socket following a radical surgery and irradiation for squamous cell carcinoma. Five of the eight exposures healed spontaneously. There were no further complications associated with these exposures.
A recent large-scale study of the Bio-eye HA orbital implant, involving approximately 200 cases of enucleations performed primarily for intraorbital neoplasm, reported no cases of orbital hemorrhage, infection, extrusion, or migration. There were only 3 cases (~1.5%) of conjunctival erosion due to a poorly fitting artificial eye, and all cases were repaired successfully. Small-degree movement of the artificial eye was reported to be excellent in 96% of these cases; large-degree movement was reported to be excellent in 22% of cases and fair in 56% of cases. Complications were minor and easily managed (Shields 1993a).
The following complications have been noted in association with surgical procedures using the Bio-eye HA orbital implant: conjunctival and Tenon’s capsule wound dehiscence, implant exposure, and implant infection. No complications have been attributed to the implant material itself. The most common complication has been early exposure of the implant, without extrusion. This complication appears to be related to surgical technique, and specifically to poor closure. This complication significantly decreases with experience in the procedure. The accumulated experience of three well-experienced surgeons has yielded a cumulative exposure rate of 3% for 366 cases in which a hydroxyapatite orbital implant was used (Perry 1991c, Shields 1992, Dutton 1992).