Toxicity evaluation of antiglaucoma drugs using stratified human cultivated corneal epithelial sheets.

To investigate the toxicity profiles of seven antiglaucoma topical eye drops and benzalkonium chloride (BAC) using stratified cultivated human corneal epithelial cell sheets (HCES) in a serum-free culture system. A range of prostaglandin analogies and preservatives, including BAC, sofZia (SZ), sodium benzoate (SB), and polyquaternium-1 (PQ) were tested. The barrier function and cell viability were examined by a carboxyfluorescein permeability assay and WST-1 assay. Histological evaluation of the HCES was also performed after application of each solution. The carboxyfluorescein permeability assay had a higher sensitivity for the detection of toxicity of test solutions than the WST-1 assay or histological examination. Latanoprost BAC, latanoprost/timolol BAC, and 0.02% or higher concentration of BAC were the most toxic, followed by latanoprost SB, latanoprost preservative-free, BAC 0.002%, and travoprost/ latanoprost PQ. Travoprost SZ and tafluprost BAC (preserved with 0.001% BAC) was the least toxic in our experimental conditions. The carboxyfluorescein permeability assay using HCES in a serum-free system was the most useful for the quantification of toxicity of ophthalmic solutions. Among the regimens examined, a BAC concentration of 0.001% or lower or non-BAC preservative sofZia was suggested to be the least toxic to the ocular surface.