Abstract
Purpose :
Exposure to ocular preservatives and ultraviolet (UV) irradiation have been associated with cataract formation. Furthermore, recent evidence shows benzalkonium chloride (BAK) penetrates into the eye, as deep as the anterior lens capsule. The purpose of this study was to evaluate the effects produced by exposure to BAK and UV irradiation on in vitro lens metabolic activity.
Methods :
The study evaluated and compared the effects of three treatments on the bovine lens: (1) BAK (2) UV irradiation (3) BAK and UV irradiation (n=5). Control lenses were exposed to phosphate buffered saline (PBS) solution. For condition 1, lenses were exposed to BAK solutions (0.01%, 0.005%, and 0.001%) for 10 min. For condition 2, lenses were exposed to UV (280-400 nm) irradiation for 1.5 h. The measured irradiance was 1132.41 µW cm-2 nm-1. For lenses in group 3 receiving both treatments, the lenses were exposed first to a BAK solution and then UV irradiation. Metabolic activity of the lenses was evaluated using the alamarBlue assay on day 0, day 2, and day 7 following exposure.
Results :
The metabolic activity for lenses exposed to BAK concentrations of 0.01% and 0.005% on day 7 were significantly less than the control lenses (p<0.05). The damage produced by exposure to 0.01% and 0.005% BAK solutions resulted in metabolic activity 68.8%±7.0% and 85.6±5.0% of the control respectively. Similarly, lenses exposed to UV irradiation had lower metabolic activity than control lenses on day 7 (p<0.05), with a metabolic activity of 80.6%±7.7% of the control. For group 3, exposure to BAK and UV produced significant cellular damage as compared to control on day 7 (p<0.05). However, there was no significant difference between the damage resulting from exposure to BAK alone (group 1) compared to BAK and UV exposure (group 3) (p>0.05).
Conclusions :
Exposure to BAK, UV, or BAK and UV produces damage to the bovine lens after 7 days. However, combined exposure of BAK and UV did not produce significantly more damage than BAK exposure alone.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.