Orbital implants in enucleation surgery: a report by the American Academy of Ophthalmology

To compare prosthetic and implant motility and the incidence of complications associated with porous and nonporous enucleation implants.

Literature searches conducted in January 2002 for 1985 to 2001 and May 2002 for October 2001 to 2002 retrieved relevant citations. The searches were conducted in MEDLINE and limited to articles published in English with abstracts. Panel members reviewed the articles for relevance to the assessment questions, and those considered relevant were rated according to the strength of the evidence.

A randomized clinical trial and a longitudinal cohort study detected no difference in implant or prosthetic movement between nonpegged hydroxyapatite porous and spherical alloplastic nonporous implants. No controlled studies were retrieved that investigated whether pegging porous implants improves prosthetic movement. Several case series indicate that patients with pegged hydroxyapatite implants have some degree of improved prosthetic motility. Longitudinal cohort studies show that sclera-covered hydroxyapatite implants have higher exposure rates than sclera-covered silicone implants, and unwrapped porous polyethylene implants have higher exposure rates than unwrapped acrylic implants. There are numerous case series that document a wide range of implant exposure rates in patients with various enucleation implants. It is difficult to compare complication rates among implant types because patient populations vary, surgical techniques differ, and follow-up periods are often limited.

Based on one randomized clinical trial, spherical alloplastic nonporous and nonpegged porous enucleation implants provide similar implant and prosthetic motility when they are implanted using similar surgical techniques. Coupling the prosthesis to a porous implant with a motility peg or post appears to improve prosthetic motility, but there are few available data in the literature that document the degree of the improvement. There is a widely variable incidence of porous implant exposure, but certain surgical techniques and the type of wrapping material seem to reduce the exposure rate. Additional research is needed to document the long-term incidence of complications related to porous enucleation implants and associated surgical techniques. This includes the use of wrapping materials and what procedural modifications, both surgical and prosthetic, are most effective in reducing these complications.