Scanning electron microscopic study of polyvinyliden fluoride degradation by ocular tissue extracts.

A scanning electron microscopic study showed that the surface of the polyvinyliden fluoride thread, used to make loops for intraocular lenses in Japan, became significantly rough after treatment with bovine iris-ciliary body extracts. The polyvinyliden fluoride degrading factor in the extract was nondialyzable, heat-labile and active at an acidic pH, suggesting that a lysosomal system might be involved in this phenomenon. Bovine extracts from the retinal pigment epithelium and choroid degraded the surface of the polyvinyliden fluoride substantially, while extracts from the cornea, iris, ciliary body and neuroretina only moderately digested it. Lenticular extract did not affect the polyvinyliden fluoride surface. It is possible that the polyvinyliden fluoride loop undergoes degradation in the eye after a long time.