A masked quantitative cytologic study of the safety of a multipurpose contact lens solution applied to the in vivo rabbit eye.

The purpose of this study was to challenge the cornea in vivo with a lens care solution (ReNu Multi-Purpose Solution, Bausch & Lomb) formulated with polyaminopropyl biguanide at a higher than standard concentration of 1.0 ppm (1.0 x 10(-6) percent) rather than the marketed 0.5 ppm (0.5 x 10(-6) percent) and to evaluate any cytotoxic epithelial response. Test solutions included the modified formulation of Bausch & Lomb ReNu Multi-Purpose Solution (poloxamine, EDTA, borate buffer, and polyaminopropyl biguanide) and Bausch & Lomb Hypo-Clear unpreserved, isotonic saline. A dose of 50 microL of each solution was administered to the superior limbus of 10 pigmented rabbits free of anterior segment disease. Neither the unpreserved saline solution nor the more highly concentrated multipurpose solution produced significant toxic effects on the corneal epithelial cells and compared favorably with previously reported incidences of desquamating cells in the normal corneal epithelium.