Treatment of the postenucleation socket syndrome with a new hydroxyapatite tricalcium phosphate ceramic implant

Surgical correction of the postenucleation socket syndrome (PESS) is challenging. Various biomaterials are used for reconstruction of the anophthalmic orbit, often with unsatisfactory long-term results. Implants have been placed between the periorbital and the orbital floor. The authors describe a new material composed of hydroxyapatite tricalcium phosphate (HA-TCP) in the form of ceramic blocks, to be placed into the orbital fat as a new surgical site.

Ten patients with PESS underwent surgery to compensate the volume deficit of the anophthalmic orbit. Blocks of HA-TCP were created by fragmentation of a larger piece, tailored as needed, and implanted in the orbital fat. The patients were monitored regularly with clinical and radiologic examinations to evaluate the behavior of the implants.

The volume of the HA-TCP was measured in 5 cases (mean, 2.95 +/- 1.08 ml). A significant reduction of enophthalmos was obtained: mean Hertel exophthalmometry measured 12.7 +/- 2.5 mm preoperatively and 14 +/- 2.4 mm postoperatively (p < 0.05). The average prosthesis volume was significantly reduced in the cases measured: 2.7 ml +/- 0.94 ml preoperatively and 1.8 +/- 0.7 ml postoperatively (p < 0.02). There was a negative correlation between the HA-TCP implant volume and postoperative prosthesis volume (correlation coefficient = -0.925; p < 0.05). According to photographic evaluation, correction of the enophthalmos and of the superior sulcus depression were obtained in 70% and 90% of cases, respectively. Magnetic resonance imaging seems to demonstrate that the blocks become well integrated into the surrounding orbital tissue.

The HA-TCP blocks correct some anomalies of PESS. Placement of the blocks directly into the orbital fat is a promising alternative to the traditional subperiosteal location.