Evaluation of cytotoxic potential and inflammatory response of different types of contact lenses before wear

Abstract

Purpose: The goal of this study was to evaluate the cytotoxic potential and inflammatory response induced by different types of Daily Disposable Lenses (DDL) and Monthly Disposable Lens (MDL) before wear. Method: Four different brands of DDL contact lens (CL) (Delefilcon A, Nelfilcon A, Nesofilcon A and Stenfilcon A) and MDL (comfilcon A, Lotrafilcon B, Balafilcon A and Senofilcon A) were used in this study to test for their inflammatory potential and for cellular toxicity. To test for any discrepancy between lots three different lots of each brand were included in the study. Lenses were co-incubated with a murine macrophage cell culture for 8h. After co-incubation cellular viability was accessed by MTT assay (3 (4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) and lactate dehydrogenase (LDH) leakage assay. The inflammatory response was measured by quantifying the Tumor Necrosis Factor alpha (TNF-α) produced by macrophages by ELISA. Results: The cellular viability studies with the new CL indicated that for the same brand there is some variability between lots. All lots of Stenfilcon A showed high values of cellular viability (100%), being considered non-cytotoxic. However, some lots of Delefilcon A, Nelfilcon A, Nesofilcon A and Lotrafilcon B induced low values of cellular viability, which could be cytotoxic. The results obtained with new CL regarding TNF-α showed that Delefilcon A, Senofilcon A and Balafilcon A induced the secretion of this pro-inflammatory cytokine. Conclusion: These results alert for the ability of some CL to induce some levels of cytotoxicity, viability values under 80%, and induce the secretion of TNF-α a pro-inflammatory immune cytokine. Together these results indicate the presence of some toxic compounds in the blister pack solution that may reduce cellular viability and potentiate an inflammatory response.