Verofilcon A contact lenses (CLs) demonstrate a low adhesion of Asian dust particles, which can easily be removed with rinsing, according to research published in Clinical Optometry. These findings suggest that verofilcon A may be the preferred CL for individuals who spend time in areas high in pollen or other allergens.
Researchers performed a comparative analysis between verofilcon A (n=16) and etafilcon A (n=16) CLs and examined the ability of both lens materials to repel Asian dust — a yellowish allergenic dust present in East Asia. The team added 0.01 mg of Asian dust to a 2 mL saline solution and dropped it onto the surface of each CL. The lenses were left for 1 hour before shaking them for 1 minute and rinsing them 3 times with saline solution. The samples were then agitated by a vortex mixer for 1 minute before being rinsed an additional 3 times.
Verofilcon A lenses showed less adhesion of dust particles and a smaller adhesion area compared with the etafilcon A lenses. At baseline, both lens materials adsorbed a similar number of the particles (verofilcon A, 919; etafilcon A, 901). After initially rinsing the lenses, the verofilcon A lenses retained significantly less particles than the etafilcon A lenses (297 vs 523; P =.003) which was reduced to 5 vs 378 after vortexing (P <.001). Dust adhesion area was 3.6% for verofilcon A lenses compared with 10.2% for the etafilcon A lenses after rinsing (P =.002) which was reduced to 0% vs 5.2% after vortexing (P <.001).
Asian dust is a weather phenomenon that comes from surface winds and dust storms originating in the deserts in Mongolia, northern China, and Kazakhstan. This dust can include large amounts of quartz, feldspar, clay, and other minerals with a particle size distribution of approximately 4 to 7 µm in diameter. These particles at diameters of 2.5 μm or larger can be hazardous to ocular health when they enter the body, exacerbating conditions such as allergic conjunctivitis. These particles can also cling to contact lenses and exacerbate ocular discomfort.
“[Soft CLs] made of silicone hydrogel material are nonionic, so the lens surface is electrically positive or negative zero. Ionic lenses, on the other hand, are charged with negative ions, so they easily attract proteins and stains that are charged with positive ions,” the study authors note. “These results suggest that verofilcon A is made of a material that is less likely to adhere to not only pollen particles but also to Asian dust particles.”
This research is limited by the strict use of daily disposable CL materials.
Disclosure: This research was supported by Alcon Japan Ltd. Please see the original reference for a full list of disclosures.
Mimura T, Fujishima H, Uchio E, et al. Adhesion of Asian dust particles to verofilcon A soft contact lenses. Clin Optom. Published online October 28, 2022. doi:10.2147/OPTO.S381763