Study of the Effectiveness of Multipurpose Solutions on the Bacterial Disinfection of Silicone Hydrogel Contact Lenses In Vitro

Abstract

Objectives:To assess the antimicrobial effectiveness of multipurpose solutions in regard to the disinfection of silicone hydrogel contact lenses (CL) using a study of clinical bacterial isolates from ocular material.Methods:Three multipurpose solutions (solution A: polyhexamethylene biguanide 0.00025 g/100 mL; solution B: polyquaternary-1 0.001% and myristamidopropyl dimethylamine 0.0006%; and solution C: polyaminopropyl biguanide 0.00013% and polyquaternary 0.0001%) were used as a 3-phase disinfection on silicone hydrogel CL contaminated with bacteria from clinical isolates that were divided into five groups (group 1: Pseudomonas aeruginosa; group 2: Staphylococcus aureus; group 3: Staphylococcus epidermidis; group 4: Streptococcus spp; and group 5: enterobacteria).Results:No differences were observed between the 24- and 48-hr measurements in any of the samples, and the positivity of microorganisms in T0 was 100% for all solutions; it was 0% in T3. Therefore, only steps T1 (rubbing followed by rinsing) and T2 (rubbing followed by rinsing and immersion of CL into solution) were considered for analysis at the 24-hr measurement time. Throughout the phases, a decrease in the number of bacteria was observed, culminating in the elimination (no recovery) of all microorganisms in the three solutions.Conclusions:At the end of the proposed process, the tested solutions were effective.

Common Ophthalmic Preservatives in Soft Contact Lens Care Products: Benefits, Complications, and a Comparison to Non-Preserved Solutions

“… 33 , 49 Another claims PHMB is effective against clinical isolates of these common causative bacteria when adhered to silicone hydrogel CLs only after full completion of manufacturer cleaning recommendations, and not after any of the intermediate steps (must be rubbed and rinsed, stored at minimum manufacturer recommended time, and rinsed again before application). 50 Overall, the above studies indicate adequate efficacy of PHMB solutions against bacteria.…”

“…Myristamidopropyl dimethylamine (Aldox), an amidoamine, effectively inhibits fungi and amoebae via cationic disruption of cell membranes. 50 , 63 …”

“…Myristamidopropyl dimethylamine (Aldox), an amidoamine, effectively inhibits fungi and amoebae via cationic disruption of cell membranes. 50,63 Similar to PHMB, studies disagree on whether PQ-1 is effective against S. marcescens. Three studies found PQ-1 to be effective, 45,46,66 while three failed to find a meaningful reduction in the bacterial load.…”

“…Correa et al (as previously outlined in this section) reported in 2018 that PQ-1 plus Aldox MPS (and PHMB and PQ-1 plus PHMB MPS) was effective against S. aureus, S. epidermidis, S. pneumoniae, P. aeruginosa, and Enterobacteriaceae, but this was only true after completion of the full manufacturer's cleaning recommendations, including both rinsing and rubbing steps. 50 bacteria, fungi, and amoeba after only a 6-hour soak, indicating the rubbing step may be unnecessary. 64 As for safety of PQ-1, a Phase I clinical trial showed safety at a concentration of 0.005%, which is five times the commercially available concentration.…”

Impact of the Type of Crosslinking Agents on the Properties of Modified Sodium Alginate/Poly(vinyl Alcohol) Hydrogels

“…As far as the role of hydrogel matrices in the medical field is concerned, an important application is wound dressings, which can be used in the treatment of burn wounds, pressure ulcers as well as post-operative wounds. Moreover, hydrogel matrices are used in the production of contact lenses, in tissue engineering and as a controlled drug release system [2,[7][8][9][10]. Currently, hydrogels based on natural polymers, such as polysaccharides and proteins, are very popular and desirable.…”