Abstract
Purpose :
To study the influences of modern multi-purpose solutions (MPS) on in vitro model tear-protein uptake and surface properties of Acuvue2 lenses and lens-wear comfort and tear film stability in vivo.
Methods :
Dynamic water-advancing (Θadv) angles on Acuvue2 (AV2) pre-soaked for a week in saline and MPS [Cleanoz (CN); ClearCare (CC); BioTrue (BT); PureMoist (PM); Revitalens (RL)] was measured by sessile-bubble method. Model proteins uptake (2-hour exposure) was evaluated using BCA assay. The contact line propagation rates (CLPR) of a mineral oil drop on the lens surface were measured; friction-drag on AV2 was calculated as a ratio of the CLPR measured after MPS-exposure divided by the CLPR in the absence of MPS. 40 subjects (20 males and 20 females) completed the clinical trial in which pre-corneal and pre-lens NITBUTs were measured using Medmont instrument. Pre-soaked lenses in designated MPS were worn bilaterally; comfort and pre-lens NITBUTs were evaluated after 0.5 and 2 hours of lens-wear.
Results :
For lenses pre-soaked in CN, Θadv was 83±4°; adhesion tension ( γadh = γa-w cos Θadv) was 5.7±2.7 mN/m; for pre-soaked in MPS, Θadv became 3±2° and γadh became 34±4 mN/m, close to the surface tension of corresponding MPS. CC, BT and PM did not change friction-drag between oil and lens-surfaces. However, for lenses soaked in RL, the contact-line propagation rate was 24±3% higher than the initial rate, indicating a reduction of friction-drag between oil and lens surfaces after exposure to RL. No statistically significant differences in lens-wear comfort ratings were reported among all MPS-soaked lenses. Values of the normalized pre-lens tear film stability (NITBUT/pre-corneal NITBUT) were similar among pre-soaked lenses in all MPS except for the lenses soaked in RL, for which normalized pre-lens tear film stability values were 23±2 % higher than for CN and other MPS. Protein uptake for lenses soaked in CN, CC, BT, PM, and RL were 173±3, 177.4±5, 168±1.7, 168±2.4, 164±1.3 µg, respectively.
Conclusions :
No significant correlation was found between lens γadh or Θadv after exposure to MPS and NITBUTs or lens-comfort ratings. However, a statistically significant increase (p=0.001) of NITBUTs after soaking in RL is associated with a decrease in both model protein uptake and friction-drag (p=0.0001) between oil drop and lens surfaces.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.