Silicone hydrogel contact lenses effects on eyelid tissues: Lens care influence

Abstract

Purpose: Properties of different CL care solutions affect their performance in clinical use. Solution chemistry impacts the outcome of the clinical variables and wearing experience, as well as the safe efficacy against microorganism. The aim of this study was to investigate the possiblemicrobial contaminations of CL care solutions, CLs and storage cases during a clinical intervention study. Method:MPS solutions [MPS-A (PQ+ALD),MPS-B (PHMB),MPSC (PHMP+PQ)] were used with SiHy-A (Lotrafilcon B) and SiHy-B (Comfilcon A) CLs for three 4-week periods by seventeen experienced CL users. Left-over solutions (15 to 100mL), CLs (one from each subject) and storage lens cases (PE)were collected for analysis of possible microbiological contamination. Results: Contamination rate of the left-over solutions was 3/17 for MPS-A, 4/17 for MPS-B and 2/17 for MPS-C. Contaminated solution samples had 1 to 2 CFU/plate, thus contamination rate was very low (0.01 to 0.02 CFU/mL of solution). Contaminated CLs were SiHy-B (3/24) while SiHy-A lenses were found clean (0/27). Of the contaminated CLs, one was used with MPS-A and two with MPS-B. Most of the storage cases were found contaminated, rates being 14/17 for MPS-A, 10/17 for MPS-B and 9/17 for MPS-C. Conclusions: Preservative efficacy of each solution during the four week intervention period was good. Only three out of fifty one CLs were found contaminated, thus solutions disinfected the lenses well. Major part of the storage cases were found contaminated, thus the use of antimicrobial storage cases could diminish the risk of storage case contamination. These results with the care solution chemistries can be used together with the clinical variables to establish the relationship between a safe and comfortable care solution-CL-storage case combination.