A scanning electron microscopic study of nylon degradation by ocular tissue extracts.

A scanning electron microscopic study showed that the surface of the nylon used for corneoscleral wound closure was smooth, while the nylon suture thread used to fix the intraocular lens against the iris showed cracks and roughness on its surface. The surface of the nylon thread was also roughened after treatment with bovine iris-ciliary body extracts. The nylon-degrading factor in the extract was nondialyzable, heat-labile, active at acidic pH, and inhibited in part by leupeptin, suggesting that lysosomal enzymes may be a factor in this phenomenon. Of the bovine ocular tissues, ciliary body extract degraded the surface of the nylon thread most significantly. The nylon surface was moderately digested by the retinal pigment epithelial extract, and slightly eroded by the extracts from the iris, sensory retina, and choroid. Corneal and lenticular extracts did not affect the nylon surface. Nylon suture thread may be hydrolyzed by lysosomal enzymes and should be considered a late-degrading suture.