Compatibility of the Tangible Hydra-PEG coating with lens
cleaning solutions
Tangible Hydra-PEG is a covalently-adhered hydrogel coating that improves wettability throughout the
lens lifetime when properly maintained. Optimum lenses treated with Tangible Hydra-PEG should be
cleaned daily with either Unique pH or Clear Care. Abrasive or alcohol-based cleaners should never be
used on Hydra-PEG lenses, as these cleaners can remove the coating and reduce lens wettability.
Untreated lenses had a contact angle greater than 90. The following chart shows that coating with
Tangible Hydra-PEG reduced the contact angle by an average of 50% throughout the lifetime of the lens
when a recommended cleaning regimen is followed.
In this experiment, Hydra-PEG lenses received one of the following treatments: manual rubbing with
Unique pH with 20 seconds representing 1 day of cleaning (10 minutes per month), or repeatedly soaking
the lenses in Clear Care hydrogen peroxide solution. The advancing contact angles were measured after
each representative month of treatment. Prior to measuring the contact angles, lenses were washed in
saline to remove the residual lens care solution. Both Unique pH and Clear Care maintained the HydraPEG coating and demonstrated a significant improvement over uncoated lenses and are therefore
recommended for use with Tangible Hydra-PEG lenses.
In summary, patients wearing Tangible Hydra-PEG lenses should use Unique pH or Clear Care for daily
cleaning of their lenses. Physically abrasive and alcohol-based cleaners are not compatible with the
coating and should never be used with Tangible Hydra-PEG lenses. These types of cleaners can completely
remove the Tangible Hydra-PEG coating, resulting in contact angles greater than 90. With proper care,
Tangible Hydra-PEG maintains lens wettability for one year.