Approximately 20% of daily disposable soft contact lens wearers may be reusing their lenses, according to research published in Optometry and Vision Science. Investigators determined this prevalence through reported contact lens case use data, which they suggest is a more suitable surrogate for true daily disposable lens use, according to the report.
Researchers performed a secondary analysis of data from 5 multi-site fieldings from the Contact Lens Risk Survey (ClinicalTrials.gov Identifier: NCT03305484), which included a total of 1059 soft contact lens wearers (age range, 12-33 years; 68.7% women and girls). Participants self-reported lens replacement and lens case use frequency, and identified their habitual lenses utilizing a photographic image. Compliant daily disposable lens use was determined based on participants reporting daily replacement, not using a lens case, and accurately identifying a brand approved for daily replacement. Individuals who met at least 2 of these 3 criteria were considered to wear daily disposable lenses.
According to this classification, 154 participants (14.5%) were categorized as daily disposable wearers, 896 participants (84.6%) were categorized as reusable wearers and 9 participants (0.8%) were unable to be categorized due to missing or conflicting data.
The researchers observed congruence among all 3 daily disposable assignment factors for 106 (68.8%) of the lens wearers. The largest discrepancy among daily disposable wearers was using a lens case (n=32; 20.8%). Reusable lens wearers were more likely to have agreement among all 3 factors (n=798; 89.1%, P <.001), the report shows.
“In conclusion, in this analysis of over 150 daily disposable lens wearers, one in five may be storing and reusing their lenses. This behavior may confound adverse data in studies by underestimating the benefits of daily disposable soft contact lens wear,” according to the researchers. “Not using a lens case is a more conservative surrogate of true daily disposable lens wear and should be assessed when evaluating daily disposable lens-wearing compliance in research studies and clinical practice.”
Study limitations include a retrospective nature, the relatively small sample size of daily disposable wearers, and the use of convenience sampling in a subset of participants.
Wagner H, Zimmerman AB, Lam D, et al. Defining daily disposable contact lens wear in a clinical study. Optom Vis Sci. Published online December 30, 2022. doi:10.1097/OPX.0000000000001985