Actinomyces infection in porous polyethylene orbital implant

Background: A 60-year-old patient developed actinomycotic inflammation within a porous polyethylene orbital implant which she received following enucleation. Methods: She had repeated conjunctival exposures with inflammation the primary implant was removed and replaced with another one. Results: The anterior two-thirds of the porous implant was infiltrated with numerous actinomycotic granules surrounded by polymorphonuclear cells and necrotic debris. The organisms were demonstrated with Gram stains on the histopathologic preparations and with scanning electron microscopy. Within the zones of inflammation, the polyethylene skeleton of the implant was extensively damaged. Conclusion: Actinomycetes have been described as causative organisms in conjunctivitis, blepharitis, canaliculitis, dacryocystitis and keratitis, but to the best of our knowledge actinomycotic involvement has never been reported in an infected porous orbital implant.     

Diplopia following porous polyethylene orbital rim onlay implant

An 81-year-old man with ocular irritation associated with lower eyelid retraction, horizontal laxity of the lower eyelids, and hypoplastic inferior orbital rims underwent bilateral placement of porous polyethylene orbital rim onlay implants. Two weeks after surgery, he developed vertical binocular diplopia on downgaze. Examination of extraocular motility demonstrated limited infraduction OD. Surgical exploration revealed scarring in the anterior orbit between the inferior rectus pulley and the orbital implant. The orbital implant was found to lie higher than the inferior orbital rim. After surgical lysis of the scar and reduction of the vertical height of the implant, the patient's diplopia resolved. Orbital connective tissues critical to ocular motility may be abnormally superficial in orbital rim hypoplasia. Onlay grafts must be carefully placed so that they do not interfere with these tissues.     

The quasi-integrated porous polyethylene orbital implant

PURPOSE: To describe a new quasi-integrated porous polyethylene orbital implant that combines the advantages of host tissue incorporation and improved motility with a single-stage surgery. METHODS: Twenty-four consecutive patients undergoing primary or secondary orbital implantation received the quasi-integrated porous polyethylene implant. Approximately 6 weeks after implantation, a custom-fitted prosthesis was made by an impression technique to provide a "lock-and-key" fit with the orbital implant. Postoperative complications and motility of the prosthetic shell were evaluated. RESULTS: During the 27-month period between December 1998 and March 2001, 24 patients received the quasi-integrated porous polyethylene implant as a buried orbital implant. Thirteen patients received the implant as a primary orbital implant after either evisceration or enucleation and 11 patients received the implant as a secondary orbital implant. Follow-up ranged from 3 months to 30 months, with an average of 16.9 months. All patients were considered to have good motility of their prosthetic shell at their final follow-up visit. No cases of implant extrusion or migration were noted. Two patients required deepening of their inferior fornix to accommodate the increased motility of their prosthesis. CONCLUSIONS: The new quasi-integrated porous polyethylene orbital implant provides improved motility without the need for secondary placement of pegs or screws. It has the advantage of biocompatibility, allowing host tissue incorporation to resist implant migration and extrusion. The implant is available in three sizes: small, medium, and large, approximating the volume of a 16-, 18-, and 20-millimeter sphere, respectively.     

An infected porous polyethylene orbital implant

A 75-year-old man underwent enucleation with placement of a porous polyethylene orbital implant (Medpor, Porex Technologies, Fairburn, GA, U.S.A.). Over the next 5 years, he was seen on numerous occasions with socket discharge that was unresponsive to a variety of eyedrops. Exposure and re-exposure of the implant occurred, and the implant was removed. Histopathologic assessment was consistent with an infectious process within the implant. Postoperatively, the patient's symptoms and signs resolved. Porous orbital implant infection is rare. The diagnosis may be delayed as the initial symptoms and signs (discharge, conjunctival inflammation) may easily be attributed to prosthesis wear. With time, and persistence of the symptoms despite numerous treatments, infection should be suspected.     

Abscessed porous polyethylene (Medpor) orbital implant: a case report

We report the evolution of clinical features of orbital implant infection in a 42-year-old man. Despite appropriate treatment recurrent conjunctival dehiscence could not be prevented. Explanation of the implant resulted in complete resolution of symptoms. Histopathological examination confirmed focal necrotising acute inflammation with the presence of colonies of the organism in the deep substance of the implant.     

Mycobacterium abscessus infection in a case of recurrent orbital implant exposure

Exposure is one of the most frequent complications of porous orbital implants, while infection is rarely observed. Atypical mycobacteria are ubiquitous germs of mostly variable pathogenicity. A patient with recurrent orbital implant exposure is described, in whom a final diagnosis of Mycobacterium abscessus infection was made on culture of the orbital implant remnant at its removal. In orbital implant exposure, infection with unexpected organisms should be considered and in these cases only the complete removal of the implant may allow the socket to settle.     

Eyelashes on an extruding porous polyethylene orbital implant

This photo essay describes a patient with eyelashes perpendicular to the extruding part of a porous polyethylene orbital implant. The upright position of these eyelashes created the impression of growth on the extruding implant, but they are lost eyelashes that became entrapped in the pores of the implant.     

Kiel bone as orbital implant following enucleation

During the last 4 1/2 years a Kiel bone was inserted as implant in 53 patients after enucleation. Two times, the implant had to be removed. Recurring conjunctival wound dehiscence and ‘phantom-pain’ were the reasons. In 51 patients the Kiel bone was well tolerated and was invaded with fibrous tissue, as the histologic examination proved. Echographic characteristics, X-ray photographs and CT-scan appearance are described.     

Cyst formation associated with porous polyethylene orbital floor implant

A 28-year-old female presented with hyperglobus and inferior scleral show after the repair of an orbital floor fracture using a porous polyethylene (Medpor) implant. CT revealed a large inferior orbital cystic mass displacing the globe. The cyst was explored and excised and the implant was found to be free from any attachment to surrounding tissues and hence, removed without difficulty. The reason for the cyst development was most likely inadvertent epithelial inclusion at the time of surgery-a recognized risk with insertion of any foreign body via transconjunctival approach. Porous implants when placed in the subperiosteal space might not get incorporated with surrounding tissues and therefore behave like any traditional nonporous alloplastic material.     

The bioceramic orbital implant: a new generation of porous implants

PURPOSE: The authors describe a new generation of porous orbital implant made of aluminum oxide (Al2O3) and compare it with the hydroxyapatite orbital implants (Bio-Eye and FCI hydroxyapatite). METHODS: The authors examined the new implant macroscopically, with chemical analysis and microscopically with scanning electron microscopy. Animal implantation studies were performed using six adult male New Zealand albino rabbits. Implant vascularization was evaluated by means of magnetic resonance imaging and histopathologic sectioning. RESULTS: The Bioceramic orbital implant was found to have very uniform pore structure with an average pore size of 500 microm. The implant was 99.9% aluminum oxide on x-ray diffraction. Magnetic resonance imaging in vivo vascularization studies demonstrated enhancement of the implant to its center by 4 weeks after implantation in the rabbit. Histopathologically, fibrovascularization occurred uniformly throughout the implant and was noted by 4 weeks. CONCLUSIONS: The Bioceramic orbital implant represents a new porous orbital implant that has a very regular and extensive interconnected pore system, is as biocompatible as hydroxyapatite, is easy to manufacture, structurally strong, and free of contaminants. It is manufactured with no disruption to marine life ecosystems as may occur in the harvesting of coral for other orbital implants. It is less expensive than currently available hydroxyapatite implants and was approved by the U.S. Food and Drug Administration in April 2000.     

Free orbital fat graft to prevent porous polyethylene orbital implant exposure in patients with retinoblastoma

PURPOSE: To determine if porous polyethylene orbital implant (Medpor) exposure can be prevented in retinoblastoma patients when the implant is placed in combination with a free orbital fat graft over the anterior surface of the implant. METHODS: Free orbital fat grafts were performed after enucleation and Medpor implantation, and results were compared with patients who underwent conventional enucleation and Medpor implantation without an orbital fat graft. RESULTS: Although implant exposure occurred in 13 of 39 eyes (33.3%) that had conventional enucleation and Medpor implantation, exposure did not develop in any of the 38 eyes that had the combined procedure with a free orbital fat graft. CONCLUSIONS: These findings suggest that a free orbital fat graft is a simple, effective way to prevent orbital implant exposure in patients requiring enucleation and Medpor implantation.     

Retroscleral implantation technique for porous polyethylene orbital implant after evisceration.

The authors developed a technique for the retroscleral implantation of a porous polyethylene orbital implant after evisceration for the placement of an adequately large orbital implant without wound tension. The surgical results of the technique in 27 patients are reported. The technique involves the severance of the optic nerve after standard evisceration and the insertion of the orbital implant into the retroscleral and intraconal space through the side of the scleral shell. All patients received a 20-mm orbital implant. No complications such as infection, implant exposure, or worsened implant motility were observed during the average follow-up period of 22.4 months. Retroscleral implantation of the orbital implant after evisceration may be an appropriate procedure that allows placement of a large orbital implant without exposure or decreased implant motility.     

Postoperative orbital fluid accumulation masquerading as subperiosteal orbital abscess: A case report and literature review

We herein present the case of a postoperative orbital fluid accumulation in a 1.5-year-old boy masquerading as subperiosteal orbital abscess (SPA). The patient was admitted to our hospital under the impression of orbital cellulitis with SPA. He subsequently underwent endoscopic sinus surgery and received external drainage for decompression. A significant amount of fetid odor abscess was drained from the subperiosteal space. However, a new episode of eyelid swelling was noted 1 week after the operation. Furthermore, a sinus computed tomography showed a very similar picture of the swelling compared with the preoperative image. Under the impression of recurrent SPA, a second operation was then performed. This time, however, only a small amount of granulated tissue and serosanguineous fluid was found. No microorganisms were cultured from this tissue/fluid, which ruled out any possible infection. It is thus a challenge to establish a differential diagnosis between postoperative fluid accumulation and SPA.