Effect of lens care system on silicone hydrogel contact lens wettability

Purpose: The purpose was to compare the effect of the repeated usage of two care systems (one hydrogen peroxide cleaning and disinfecting system and one polyaminopropyl biguanide (PHMB) containing multi-purpose system) with silicone hydrogel contact lenses worn for three months on a daily wear modality. A specific aspect of interest was of the effect of the care systems on contact lens wettability. Methods: Seventy-four symptomatic contact lens wearers, habitually wearing either ACUVUE® OASYS® (n = 37) or PureVision™ (n = 37), constituted the study population. The study was a two-arm prospective, investigator-masked, bilateral study of three-month duration to evaluate the effects of CLEAR CARE® compared with renu® fresh™. The subjects were randomized to one of the two lens care systems. Contact lens wettability and surface cleanliness were assessed with the Tearscope and reported in terms of pre-lens non-invasive break-up time (PL-NIBUT) and visible deposits. Baseline assessments at enrollment were with the subjects’ own contact lenses worn for at least 6 h when using their habitual PHMB-preserved care system and at the dispensing visit with new contact lenses. At the follow-up visits, the contact lenses were worn for at least 6 h, and were at least 11 days old for ACUVUE® OASYS® and 25 days old for PureVision™. Results: The results obtained showed that: (i) with CLEAR CARE®, a significant improvement in contact lens wettability was recorded compared with the habitual care system at the three-month follow-up visit (mean median PL-NIBUT 5.8 vs. 4.0 s, p < 0.001). Further, with this same lens care system a significant increase in wettability was observed at the three-month follow-up visit compared with dispensing (mean median PL-NIBUT 5.8 vs. 4.5 s, p = 0.022). (ii) Whereas no difference in contact lens wettability was observed at dispensing between the two lens care groups (mean PL-NIBUT: 4.5 vs. 4.2 s, p = 0.518), a significantly more stable pre-lens tear film was observed with CLEAR CARE® than with renu® fresh™ at both the two-month (mean PL-NIBUT: 4.6 vs. 3.7 s, p = 0.005) and three-month (mean PL-NIBUT: 5.8 vs. 4.2 s, p = 0.028) visits. iii. With renu® fresh™, no significant differences were observed at the end of three months of use compared with either the habitual care system or the new contact lens solution (mean PL-NIBUT: 3 M 4.2 vs. Disp 4.2 s (p = 0.420) vs. enrolment habitual care solution 5.1 s (p = 0.734)). iv. With CLEAR CARE® significant increases in the incidence of surfaces free of both mucus (3 month 95%. vs. habitual solution 82% enrolment; p = 0.005) and lipid (3 month 87% vs. habitual solution 72% enrolment; p = 0.009) were observed. Conclusion: Significantly better contact lens wettability and surface cleanliness were achieved for ACUVUE® OASYS® and PureVision™ with CLEAR CARE® than with renu® fresh™ at the end of three months of use