The Effects of Artificial Tear Formulations and Anti-inflammatory Agents on the Cultured Keratocytes of Rabbit

ABSTRACT

We investigated the biological effects and cytotoxicity of the artificial tear formulations and anti-inflammatory agents on the cultured keratocytes of rabbit in vitro by using lactate dehydrogenase (LDH) leakage assay and transmission electron microscopy. In the artificial tear fomualations, the LDH titer of the Tears naturale and Protagent were more increased with time, but the Tears naturale II and Tears naturale free was slowly progressed or has narrow range of LDH increasing. In the anti-inflammatory agent, the LDH titer of the all eye solutions was increased with time, especially Maxidex and Fluorometholone. Non-steroid, Decrol was less than other anti-inflammatory agents in Na+, K+, Cl- electrolyte compositon. Especially, the LDH titer of the artificial tear formulations and anti-inflammatory agents containing the benzalkonium chloride (BAC) or low Na+, K+, Cl- composition was more increased with time. The typical rabbit keratocytes were elongated and had not prominent nuclei. But the higher the titer of LDH, the keratocytes were visible round and swollen, and were injured with the disruption of plasma membrane, vacuole formation in cytoplasm, and damage of nuclei in transmission electron microscopy. As the use of topical drug containing low Na+, K+, Cl- or Benzalkonium chloride should be induced a particulary toxic effect on keratocyte, we should be carefully use these topical eye solutions, especially when the epithelium is denuded.