Analysis of Patient Practices and Attitudes towards Compliance with Contact Lens Storage Cases in Relation to Microbial Contamination Levels




Ndedi, Sarah B.


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Purpose: Non-compliant practices amongst contact lens wearers contribute to a high incidence of ocular complications and infections. During a contact lens-related adverse event, the infectious agent is almost always recovered from the contact lens storage case. This study measured the level of actual compliance with lens storage case hygiene, characterized the attitudes of contact lens wearers in regards to lens storage case hygiene, and correlated these factors with microbial contamination of the contact lens storage case. Since compliance is based upon patients’ adherence to physicians’ recommendations, this study also surveyed eye care practitioners about their knowledge of contact lens case care to identify areas of education that need to be addressed within both the practitioner and lens wearer populations. Hypotheses: 1) Certain personality traits and negative attitudes toward compliance with contact lens wear and care may be indicative of non-compliant hygiene practices and, in turn, result in higher levels of contact lens storage case contamination. 2) Recommendations by eye care practitioners regarding contact lens storage case care may be inadequate and may contribute to inappropriate care practices and low compliance rates amongst lens wearers. Methods: In the first arm of this study, a contact lens storage case drive was conducted at the University of Texas Southwestern Medical Center. During the contact lens storage case drive, participants completed anonymous, self-administered questionnaires, and submitted their used contact lens cases for analysis. Collected surveys served to characterize patient attitudes towards proper lens storage case hygiene and calculate compliance scores based on patient reported practices. The cases were then analyzed using a crystal violet assay to stain and quantify the level of biofilm (matrix of microorganisms) present within the wells. In the second arm of the study, 616 eye care practitioners were invited to complete a survey regarding their recommendations for proper lens storage case hygiene. Data summarizing the overall results of each set of surveys were compiled and statistical analyses were conducted to determine trends and correlations between variables. Results: In the patient group, 90% of individuals were deemed as having positive attitudes (score of 1 and above). The average attitude score was 10 ± 6.7 with a range of -7 to 26. Average compliance was 64% ± 20% with a range of 4-100%. Approximately 57% of subjects displayed poor compliance (≤69%), 35% average compliance (70-89%), 7% had good compliance (≥90%), and 1.5% had full compliance (100%). No significant relationship was found between the subjects’ attitude scores and compliance grades (p=0.516). The average absorbance from the crystal violet assays, used to quantify the level of biofilm, was 1.9 ± 6.5 with a range of 0.0093 to 64.1. No significant relationship was found between compliance grades and absorbance values (p=0.794). Additionally, no significant relationship was found between attitudes and absorbance (p=0.689). Certain patient attitudes and improper contact lens storage case hygiene practices reflected the reported recommendations of practitioners. Conclusions: Education about the importance of contact lens case replacement and cleaning is needed for both eye care practitioners and patients alike. Both of these educational goals could reduce the risks of infections in the contact lens wearing population.