Abstract
Purpose: :
Evaluate cellular viability of mammalian cells exposed to silicone hydrogel (SiHy) contact lenses (CL) cycled in soft contact lens care products (SCLC) using in vitro cell culture models.
Methods: :
Lens care products used: Clear Care®; AQuify® MPS and ReNu MPS® , OPTI FREE Express and OPTI FREE RepleniSH. SiHy contact lens materials: O2OPTIX, NIGHT & DAY, ACUVUE OASYS and PureVision. Cellular viability assay used for cycled SiHy contact lenses: modified USP Direct Contact Assay (ModDC). Cellular viability assay used for SCLC: Alamar BlueTM (AB) and the modified USP Elution Assay (ModEL). L929 murine fibroblastic cells (L929) were exposed to SiHy CL cycled 1 or 7Xs in the appropriate manufacturers SCLC and lens case. Viability evaluated by exclusionary dye after 24 hours exposure. Separately, L929 were exposed to a 25% concentration of SCLC and evaluated at 48 hours. Benzalkonium chloride (BAC) was the positive control for analysis of dead cells.
Results: :
O2OPTIX, NIGHT & DAY, ACUVUE OASYS and PureVision contact lenses cycled 1X and 7Xs with Clear Care, AQuify MPS and ReNu MPS were found non-cytotoxic in the ModDC assay. PureVision contact lenses cycled 1X with OPTIFREE Replenish were non-cytotoxic in the ModDC assay. NIGHT & DAY and ACUVUE OASYS cycled 1X with OPTIFREE RepleniSH were found cytotoxic in 2 of 3 trials. O2OPTIX, NIGHT & DAY, ACUVUE OASYS and PureVision CL cycled 7Xs with OPTIFREE RepleniSH were cytotoxic in the ModDC assay. O2OPTIX, NIGHT & DAY, ACUVUE OASYS and PureVision CL cycled 1X and 7Xs with OPTIFREE Express were cytotoxic in the ModDC assay. Clear Care, AQuify MPS, ReNu MPS, and OPTIFREE RepleniSH were non-cytotoxic in the AB and ModEL assays and OPTIFREE Express was cytotoxic. BAC was cytotoxic in the ModDC, AB and ModEL assays.
Conclusions: :
The ModDC assay can be used to screen SCLC with SiHy CL for possible SCLC uptake and preliminary in vitro cytotoxicity and biocompatibility. Overall rank order, least to most cytotoxic SiHy CL cycled 1 and 7Xs with SCLC and 25% SCLC was: Clear Care < AQuify MPS< ReNu MPS< OPTIFREE RepleniSH<<OPTIFREE Express.
Keywords: contact lens • ocular irritancy/toxicity testing • cornea: basic science