Abstract
Abstract: :
Purpose: To review histological findings from AlphaCor artificial corneas explanted from human patients so as to correlate them with clinical histories and assess adequacy of biointegration. Methods: Specimens were available from 14 devices explanted from AlphaCor recipients following complications; in all cases the explanted device was replaced either with a second device or with donor graft tissue. Each specimen was divided into half, one being processed and stained with haematoxylin and eosin, Periodic acid–Schiff, Masson's trichrome, von Kossa's method, alizarin red and Grocott's methenamine–silver nitrate, while the other underwent scanning electron microscopy. Results: Of the 14 specimens, 3 had been removed due to optic calcification caused by topical medication, 1 due to iatrogenic optic damage, 1 due to optic fungal infection and 9 due to complications associated with melting of tissue surrounding the device. All devices demonstrated normal skirt porosity. Collagen deposition and fibroblastic skirt invasion was greater in the non–melt related cases and similar to earlier animal findings. Cases with longer histories of melt–related complications showed more chronic inflammatory cell types around the device. Device optics demonstrated anterior brownish staining in smokers and calcium was confirmed in the 3 cases that had developed calcification. There was no evidence of separation of skirt from optic regions in any case. Conclusions: AlphaCor's sponge skirt allows biointegration by host fibroblastic cells, with deposition of collagen. The device optics appear at risk of discolouration on smoke exposure and may be affected by topical medications. Cases where melting of host stroma was observed demonstrated greater inflammatory cell populations in the device skirt. Findings are consistent with earlier animal studies suggesting that stable long–term biointegration can be achieved.
Keywords: keratoprostheses • microscopy: light/fluorescence/immunohistochemistry • wound healing