| Resumo: | To analyze changes in hydrophobicity of hydrogel and silicone- hydrogel contact lenses (CL) when preserved in different lens care systems. Every disinfecting solution contains several components and the arrangement of these agents controls the properties of the solution which can influence patient comfort and CL materials. Method Four silicone-hydrogel CL (Senofilcon A, Balafilcon A, Comfilcon A, Lotrafilcon B) and one conventional CL (Etafilcon A) and appropriate lens care solutions (Renu Multiplus™ and Biotrue (Bausch & Lomb), Optifree Puremoist and Aosept® Plus (CIBA Vision) were used. Lenses were immersed in each lens care system during 12 hours and then CL hydrophobicity was determined through water contact angle measurements using an OCA 20 instrument (DataPhysics, Germany). Measurements were performed before and after the lenses were immersed in each care solution. Two CL of each combination (CL + solution) were tested, and four measurements per lens were obtained. Results Mean values of contact angles obtained when CL were removed from their blisters (baseline value) were lower for Etafilcon A (49.6º±3.0º) and Comfilcon A (48.0º±2.8º) and higher for Senofilcon A (78.9º±2.5º), Lotrafilcon B (82.6º±1.7º) and Balafilcon A (91.5º±0.7º). Significant changes were observed on lens hydrophobicity when exposed to lens care systems depending on the CL material and the lens care. When compared to baseline value, contact angles varied between Etafilcon A: 2º and 11º, Comfilcon A: 1º and 7º, Senofilcon A: 2º and 28º, Lotrafilcon B: 14º and 31º and Balafilcon A: 18º and 29º. Conclusions The present study reveals the existence of interactions between CL material and lens care solutions that can play an important role in CL surface hydrophobicity. Lenses with baseline higher contact angles (hydrophobic) presented higher variations but these differences can be positive since in almost all of the combinations, the lenses become less hydrophobic presenting lower contact angles.
|
|---|