Abstract
Purpose:
To asses residual hydrogen peroxide (H2O2) after neutralization of two hydrogen peroxide lens care systems using both in vitro and ex-vivo methods.
Methods:
Five (5) AOCups/AODiscs per peroxide system (Clear Care® and novel peroxide system) were tested at room temperature through 100 cycles without a contact lens. Residual H2O2 of the neutralized solution was measured via UV spectroscopy in parts per million (ppm) after 1, 15, 30, 45, 60, 75, 90 and 100 cycles at 6 hour neutralization. At each test interval, pH and osmolality were also measured. Additionally, AOCups/AODiscs used with Clear Care® to disinfect silicone hydrogel contact lenses for approximately 30 days were collected from 61 study subjects and analyzed for residual H2O2.
Results:
The mean residual H2O2 for both the Clear Care® system and the novel peroxide system was below 5ppm after 100 cycles. There was no significant difference in residual peroxide levels between the two peroxide systems at any of the 8 test cycle intervals. The mean pH of both systems ranged from 6.8 to 6.9 and the mean osmolality ranged from 290-293 mOsm/kg at each test cycle up to 100 cycles. Residual H2O2 assay values from the AOCups/AODiscs used with Clear Care® by study subjects for 30 days ranged from 6ppm to 55ppm with an average of 15±8ppm. Ninety-five percent (95%) of the cases had residual peroxide below 30ppm after 30 days of use.
Conclusions:
Both the Clear Care® and the novel peroxide systems are efficacious at neutralizing H2O2 down to below 5 ppm after 100 cycles. The Clear Care® system used by study subjects resulted in slightly higher residual H2O2 concentrations, likely due to slight deactivation of the disc by tear components introduced from worn lenses. The majority of the 30-day patient used Clear Care® systems neutralized H2O2 to a level of 30ppm or less, which is below the level detectable by the ocular tissues.