Kim SI, et al. - In the present study, the researchers examined the cytotoxicities of the topical ocular dual-action anti-allergic agents (alcaftadine 0.25%, bepotastine besilate 1.5%, and olopatadine HCL 0.1%) on human corneal epithelial cells (HCECs) and their anti-allergic impacts on cultured conjunctival epithelial cells. For this investigation, they used a Methylthiazolyltetrazolium-based calorimetric assay to evaluate cytotoxicities utilizing HCECs at concentrations of 10, 20 or 30% for exposure durations of 30 min, 1 h, 2 h, 12 h or 24 h. The authors found cell viabilities reduced in time- and concentration-dependent manners. Alcaftadine tends to have fewer side effects and greater therapeutic effects than reported by the other two anti-allergic agents. Using fewer toxic agents in patients with ocular surface risk factors or presumed toxicity symptoms may be more effective.