Pathological and scanning electron microscopic evaluation of the 91Z intraocular lens

We analyzed 18 explanted 91Z anterior chamber lenses by light and scanning electron microscopy. Intermittent touch of the lens loops to the posterior corneal surface and the anterior chamber angle may have occurred. Erosion of the polypropylene loops into the anterior chamber angle recess and into the iris tissue was also observed. Fibrous tissue, uveal tissue, and inflammatory debris were noted on the loops, forming dense synechias at the points of contact with the angle recess. In some lenses the edges of the optics were sharp. Other significant manufacturing defects were rarely seen, and there was no evidence of degradation of polypropylene loops. The problems regarding surgical removal of this lens are discussed.