Comparison Of Early Fibrovascular Proliferation According To Orbital Implant In Orbital Floor Fracture Reconstruction In Rabbits

1. Hwa Lee
2. Sehyun Baek

Department of Ophthalmology, Korea University College of Medicine, Ansan, Korea

Purpose : The purpose of this study is to observe the fibrovascular tissue between the implant and orbital connective tissue and fibrovascular ingrowth into the implant in orbital floor fracture of animal model.

Methods: A standardized 6-mm diameter sized defect was made bilaterally in the maxillary sinuses to include bone and mucosa and 8 x 8 mm size alloplastic implant was inserted in 24 New Zealand white rabbits. Two different implants with 1 mm width were used: porous high-density polyethylene with barrier surface of 0.2 mm width (Medpor®, Group A) and absorbable copolymer (Macropore®, Group B). The implants were harvested at 1-, 2- and 6- weeks. H&E stains and immunohistochemical study on bFGF and CD-31 were conducted.

Results: Full thickness fibrovascular ingrowth into the implant was observed in group A after two weeks, but there was no fibrovascular ingrowth into the implant in group B. The bFGF index in Group A and B were 1.0 and 1.8 at 1 week, 2.5 and 2.8 at 2 weeks, 3.0 and 3.0 at 6 weeks. Expression of CD31 in Group A and B were 19.8 and 23.3 at 1 week, 38.0 and 49.3 at 2 weeks and 64.3 and 72.0 at 6 weeks.

Conclusions: Because absorbable copolymer implant showed no fibrovascular ingrowth into the implant, it may have an advantage in orbital wall fracture with extraocular muscle exposure. Non-absorbable porous polyethylene implant has an advantage in orbital wall fracture which is worried about implant migration and large orbital wall fracture.