Preliminary microbial assessment of used contact lens solutions and the lens care compliance of students from UP Manila.

Abstract

Proper care and use of contact lenses and lens solution should be observed, as contact lenses are prone to microbial contamination. This study aims to assess the microbial load of used contact lens solutions of UP Manila students and to determine their lens wearing history and perceived level of compliance to lens care procedures. This study also aims to test for an association between the microbial load of the used contact lens solutions, and the perceived level of compliance to each of the lens care procedures. Microbial load was determined through viable cell count. Initially, the method for inoculation was the spread plate, but was later modified using the procedure by Miles and Misra. Results showed that microbial load from used contact lenses ranged from no growth to greater than 1x10⁶ CFU/ml. Based on the microscopic observation of Gram-stained bacterial smears, contaminated used lens solutions had multiple microbial identities (15/33 PCA plates), with Gram (+) bacilli (endospore-forming) and cocci as the most common identity of the microbial load. Yeast and molds were also observed on SDA plates. Using Chi-square test, it was determined that the perceived compliance scores for most lens care procedures in the SAQ were non-homogeneous. Results suggest that a number of students perceived that they are compliant with the proper procedures of lens care. A significant association is present between the microbial growth on the lens solution and the perceived compliance of participants on washing of their hands before handling contact lenses (p-value = 0.007), and cleaning/rubbing of contact lenses immediately after it has been removed from the eyes (p-value = 0.039). The results suggest that UP Manila students to always wash their hands prior to their handling and use of contact lenses, and to clean contact lenses immediately after removal.