Histological study of epikeratophakia tissue lenses for myopia removed from two patients.

Epikeratophakia tissue lenses for the correction of myopia were removed from two patients as a result of postoperative complications such as stromal folds, complaints of glare, and decreased visual acuity. Light and electron microscopic analysis showed protrusions in Bowman's membrane and the anterior stroma corresponding to corneal folds that had been observed clinically. The epithelial cells in these areas contained many vacuolations and a thickened basement membrane. Hemidesmosomes were decreased in number. The tissue lenses had been cut 1.5 mm larger in diameter than the trephined recipient bed into which they were placed. Excess tissue lens material in the central area may have been thrown into folds by mechanical pressure, resulting in the histological changes, clinical signs, and optical distortion that necessitated removal of these grafts. Recently, the surgical technique has been modified, in an attempt to eliminate this problem.