A comparison of the efficacy and toxicity of and intraocular pressure response to viscous solutions in the anterior chamber.

An intraocular-lens abrasion test, vital dye staining, and scanning electron microscopy were used for an in vitro comparison of endothelial protection offered by four viscous solutions of 1% sodium hyaluronate (Healon), 3% sodium hyaluronate (AmVisc), 4% chondroitin sulfate (Viscoat), and 2% methylcellulose. Wide-field specular microscopy with analysis of endothelial cell density and morphologic evaluation, pachymetry, and intraocular pressure measurements were also used to study the toxicity of the viscous solutions in an in vivo cat model with and without anterior chamber washout. All four solutions provided complete endothelial protection from mechanical trauma. Endothelial cell density and morphologic nature were unaffected during the in vivo toxicity study. A mild increase in intraocular inflammation occurred at one and two days after intraocular injection with all four viscous solutions. Intraocular pressure elevations peaked within four hours after instillation of the viscous solutions and were significantly reduced by anterior chamber washout.