Forceps and vacuum injuries to the cornea: histopathologic features of twelve cases and review of the literature.

Histopathologic and ultrastructural features were examined from 11 cases of corneal injury from obstetrical forceps and one case from vacuum extraction. Four major types of histopathologic features were observed. Type I (n = 4) included large tears of Descemet's membrane with a fragment of Descemet's membrane extending into the anterior chamber at one end of the tear and scroll formation at the other end. Type II (n = 6) consisted of scrolls of Descemet's membrane at each margin of the original break. Type III (n = 2) included those with small breaks in Descemet's membrane and healing by fibrosis at and posterior to the original tear. Type IV (n = 1) contained a small break in Descemet's membrane with minimal fibrosis. Transmission electron microscopy revealed Descemet's scrolls and retrocorneal fibrous tissue. Scanning electron microscopy revealed folds in Descemet's membrane and attenuation or absence of endothelium. Spindle- and stellate-shaped cells and pigment granules were present in the area of the tear in most cases. A review of the literature is presented.