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Purpose: To histopathologically assess the extent and pattern of vascularization of explanted porous polyethylene (PP) and hyrdoxyapatite (HA) orbital implants. To compare the vascularization in PP implants harvested after enucleation versus after evisceration., Methods: This is a comparative case series of six orbital implants explanted between 11 months and 5 years and 4 months post implantation. The implants were subjected to histopathological examination with various stains, after complete decalcification., Results: There were 2 post evisceration, 3 post enucleation and 1 secondary implant. The size of the implants varied from 18 to 23 mm diameter. The reason for explantation was exposure in all the 6 cases with additional infection in 2 cases. Histopathology revealed complete vascularization up to the core of the implant in all the cases. There was evidence of chronic inflammation within all the explanted specimens. Acute inflammation was present at the site of exposure in four of the implants. Three of these implants had additional evidence of necrosis. Two cases with clinically evident infection had Gram positive cocci within the implant. Foreign-body type giant-cells, melanophages and haemosiderin laden macrophages were also observed. Eviscerated specimens showed scleral remodelling and thickening., Conclusion: All the implants were vascularized up to the core. There was histologic evidence of chronic inflammation in all the explanted implants possibly indicating the foreign nature of the implant material. The sclera did not impede vascularization of the implants in eviscerated specimens. We found no difference in the degree of vascularization of the implant in enucleated versus eviscerated implants.

Purpose: To demonstrate the potential for the use of AlloDerm as a posterior lamellar graft in the reconstruction of full-thickness lid defects., Method: In our case series, we evaluated the surgical outcome of three consecutive patients, two with an upper eyelid defect and one with a lower eyelid defect who underwent lid reconstruction using AlloDerm grafts., Results: AlloDerm was readily taken up into the wound defect, with complete coverage of its bulbar surface by conjunctiva. In all the cases, the cornea was not affected by its contact to the AlloDerm. A mucocutaneous junction formed over the margin of the AlloDerm graft with good cosmesis., Conclusion: AlloDerm has the potential to act as an effective posterior lamellar substitute in situations where there is an adequate amount of skin muscle cover available to drape over it. It is rigid enough to replace tarsus and its structure behaves as a scaffold allowing conjunctiva to readily grow over it.