High density porous polyethylene material (Medpor) as an unwrapped orbital implant

Objective: To introduce the clinical effect among patients who received an unwrapped orbital implant with high density porous polyethylene material (Medpor) after enucleation or evisceration. Methods: Retrospective analysis of a series of 302 patients with anophthalmia who underwent placement of an unwrapped high density porous polyethylene orbital implant. We compared the patients (n=180) who accepted primary implant placement with those (n=122) who accepted secondary implant placement. Parameters evaluated included: age at time of surgery, date of surgery, sex, implant type and size, surgery type, the surgical procedure and technique performed, and complications. Results: The time of follow-up ranged from 2.0 to 58.0 months (mean 32.5 months). A total of 5 of 302 (1.66%) cases had documented postoperative complications. The following problems were noted after surgery: implant exposure, 3 patients (0.99%); implant removed due to orbital infection, 1 patient (0.34%); ptosis, 1 patient (0.34%). There were no significant complications observed in other 297 cases and all implants showed good orbital mo- tility. The clinical effect of primary implant placement is better than that of secondary placement. Conclusion: High density porous polyethylene material can be used successfully as an unwrapped orbital implant in anopthalmic socket surgery with minimal complications. The material is well tolerated, nonantigenic and has low rate of infection and migration.

Effects and complications of placement of motility coupling post in porous polyethylene orbital implants

Objective： To investigate the effects and complications of primary and secondary placements of motility coupling post （MCP） in the unwrapped porous polyethylene orbital implant （PPOI） following enucleation. Methods： We investigated 198 patients who received PPOI implantation following the standard enucleation procedure in the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China, from 2002 to 2004. These patients were subgrouped into PPOI-only patients （112 cases, received PPOI following enucleation）, primary MCP patients （46 cases, received primary placement of MCP during PPOI operation）, and secondary MCP patients （40 cases, received secondary placement ofMCP 6 months after the initial surgery）. Effects and complications among these three groups were compared. Results： The PPOI-only patients took shorter treatment course when compared with other two MCP groups （P〈0.001）, without significant difference noted between the two MCP groups. However, the two MCP groups had better prosthetic motility than PPOI-only group （P〈0.001）, without significant difference between the two MCP groups. In the early stage, 2 eyes in the PPOI-only group and l eye in the primary MCP group had PPOI infection. In PPOI-only group, 3 （2.68%） eyes had PPOI exposure, which occurred after fitting the prostheses; 4 eyes （8.70%） in primary MCP group and 1 eye （2.50%） in secondary MCP had PPOI exposure, which occurred before fitting the prostheses. After prosthesis was fit successfully, the excessive discharge and granuloma were 33.9% and 1.79% in PPOI group-only, 53.3% and 8.9% in primary MCP group, and 52.5% and 7.5% in secondary MCP group, respectively. Conclusion： Both primary and secondary placements of MCP into the PPOI following enucleation can help patients to obtain desirable prosthetic motility, but may be associated with more complications. The primary placement of MCP with skilled operation in selected patients is more recommendable than secondary placement.