Thirty eyes of 25 patients who had undergone penetrating keratoplasties were examined post mortem. Available corneal buttons and donor rims were evaluated for irregularities of the trephine margins. Of 26 eyes with clear grafts, visual acuity had been 20/80 or better in 13, worse than 20/100 in six, and was unknown in seven. In four eyes with cloudy grafts, visual acuity had been 20/400 or worse. Twenty-three eyes had had one keratoplasty and seven eyes had had two or three transplants. Microscopic examination disclosed frequent overriding wound edges with Bowman's layer incarceration in the wound in 11 eyes and Descemet's membrane incarceration in 22 eyes. Wound abnormalities were correlated with the presence and degree of astigmatism. A retrocorneal fibrous tissue layer was localized at the wound in 16 eyes, extended peripherally in 11, and extended centrally in one. Iris and vitreous incarceration in the wound occurred in 14 and eight eyes, respectively. Histopathologic features contributing to visual loss included cystoid macular edema (three eyes), senile macular degeneration (four eyes), and preretinal membranes (four eyes).
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