Rinse step helps remove protein deposits from silicone hydrogel contact lenses

Optom Vis Sci. 2009;86(8):943-947.

Rinsing significantly reduced protein deposits remaining on silicone hydrogel contact lenses, a study showed.

The study included 20 patients fitted with lotrafilcon B contact lenses (CIBA Vision). Patients with suitably fitting lenses were directed to wear the lenses daily for 5 days and used Aquify Multi-Purpose Disinfecting Solution (CIBA Vision) according to the product's no-rub instructions.

At the outcome visit, contact lenses were removed from the eyes and collected with sterile metal forceps. A gloved examiner rinsed the right lenses but not the left lenses. Investigators used a 50:50 0.2% trifluoroacetic acid-acetonitrile solution to extract protein deposits from the lenses. Bradford analysis was used to quantify protein extraction, the study authors said.

Study data showed that for non-rinsed lenses, the first extraction produced 13.4 µg of protein per lens. The second extraction collected 5.8 µg of protein per lens.

For the rinsed lenses, the first extraction removed 3 µg of protein per lens; the second extraction yielded 4 µg of protein per lens.

Statistical analysis showed a highly statistically significant relationship (P < .0001) between rinsing and amount of protein extracted, the authors said.

"Rinsing a contact lens after removal from the eye removes well more than one-half of the protein associated with it," the authors said. "Further, to biochemically recover all protein from a silicone hydrogel lens, it may be important to perform more than one chemical extraction from it."