Abstract
Abstract: :
Purpose: To study the toxicity of SDS (sodium dodecyl sulfate), BAK(benzalkonium chloride), and UV-B on the cultured bovine lens, by analyzing lens optical quality using an automated scanning laser system and, for BAK,by analyzing cellular viability of lens epithelial cells. Methods: Bovine eyes, obtained from a local abattoir, were dissected in sterile conditions, and the lenses were isolated. All lenses were incubated at 37 degrees C, with 4% CO2 and 96% air atmosphere. Solutions at 0.001,0.01, 0.1, and 1% of SDS and BAK were exposed directly to the lenses (n= 80) for 15 minutes. These lenses were then rinsed 5 times each with 0.9% saline and culture medium and kept for 192 hours. Another group of lenses (n= 20) were irradiated with broadband UV-B at energy levels of 1 and 2 J/cm(0.445 and 0.89 J/cm2 in the biologically effective energy range). These lenses were kept for 504 hours. Lens optical quality was quantified using a scanning laser in vitro assay system. Cellular viability of lens epithelial cells (for BAK) was evaluated using an Alamar Blue assay. Results: The analysis of optical quality, using a scanning laser in vitro assay system, of SDS, BAK, and UV-B treated lenses showed a relative increase in BVD (back vertex distance) variability, indicating loss of sharp focus in comparison with control lenses. For example, 1% BAK treated lens was most damaging with increases in BVD variability (to 4.675 mm) showing up 168 hours after exposure, compared to the control lens values of 0.407 mm. However, 0.001% SDS treated lenses and 0.001% BAK treated lenses didn’t show any damage till 192 hours after exposure, with BVD with variabilities of 0.491 and 0.440 mm respectively. Lenses treated with 0.01% SDS showed recovery from optical damage 144 hours later after exposure. The results of the Alamar Blue assay for BAK indicate a dose-response reduction in fluorescence with a small or temporary effect at the lower concentrations (0.01 and 0.001 %) and a marked and lasting reduction at higher doses (1.0 and 0.1 %). Conclusions: This study shows that measurements of lens optical quality can provide a dose- related evaluation of chemical and UV lens damage and this can be correlated, at least in the instance of BAK, to reduced lens cell metabolism.
Keywords: ocular irritancy/toxicity testing • optical properties • metabolism