Full-thickness lamellar keratoplasty. A histologic study in human eyes

Four human eyes, obtained 38 days to 5 years after full-thickness lamellar keratoplasty, were studied by light microscopy for evidence of fibroblast proliferation and collagen formation between the donor Descemet's membrane and the recipient stromal bed. There was delayed healing in the membrane to stroma interface, but at the graft margins a relatively normal stroma-to-stroma healing response was evident. Even in the five-year specimen, bridging of recipient collagen to donor Descemet's membrane was noted only where it was associated with subgraft vascularization. All donor endothelium had disappeared. These studies indicate that in human eyes, retention of Descemet's membrane results in a weaker total graft-host bond than provided by conventional lamellar keratoplasty. In addition, this altered healing may predispose to pseudoanterior chambers that may decrease visual acuity and diminish the theoretical optical advantages of a smooth Descemet's membrane in the graft host interface.