Korean J Ophthalmol.  2006 Sep;20(3):143-146. 10.3341/kjo.2006.20.3.143.

The Survival of Freely Grafted Orbital Fat on Porous Polyethylene Orbital Implants in the Rabbit

• Kim NJ
• Choung HK
• Khwarg SI

• KMID: 754569
• DOI: http://doi.org/10.3341/kjo.2006.20.3.143

Abstract

PURPOSE: To investigate the long term survival of orbital fat grafted on a Medpor(R) implant as a method of preventing porous polyethylene orbital implant (Medpor(R)) exposure in anophthalmic sockets. METHODS: In one orbit in each of 8 rabbits, a small amount of retrobulbar orbital fat was grafted between the anterior surface of the Medpor(R) implant and overlying conjunctiva, during the enucleation and Medpor(R) implantation procedure. Two rabbits were sacrificed at 2, 4, 8 and 12 weeks postoperatively and grafted orbital fats were examined by light microscopy. RESULTS: Grafted orbital fat was well-maintained at 2 and 4 weeks, postoperatively. However, fat amounts were significantly reduced at 8 weeks, and viable fat was barely visible at 12 weeks. CONCLUSIONS: In rabbits, orbital fat grafted on Medpor(R) implants was gradually resorbed, and the fat-occupied volume was not maintained.

Keyword

Exposure; Medpor(R); Orbital fat

MeSH Terms

Time Factors
Rabbits
Porosity
*Polyethylene
*Orbital Implants
*Graft Survival
Follow-Up Studies
*Biocompatible Materials
Animals
Adipose Tissue/cytology/*transplantation

Figure

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  Fig. 1 After enucleation and hemostasis (A), a ca. 4×4×1 mm portion of retrobulbar orbital fat was excised (B) and kept in solution containing antibiotics and saline for later grafting (C). Excised orbital fat was placed on the anterior surface of the implant after attaching the four rectus muscles to the Medpor® implant (D). Tenon's capsule and conjunctiva were closed over the grafted fat (E, F).

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  Fig. 2 Histologic findings of orbital fat grafted onto Medpor® implants (×40, H&E staining). Orbital fat was well maintained at 2 weeks (A) and 4 weeks (B) postoperatively. However, at 8 weeks postoperatively fat amounts were significantly reduced and chronic cellular type inflammatory response was observed near the grafts (C). At 12 weeks, no viable fat was found, and the grafted orbital fat had been replaced by microcysts and fibrous tissue. Normal architecture and adipocytes had been lost (D). (arrow: orbital fat, arrowhead: conjunctiva, asterisk: Medpor®)

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