<p>Objective Analysis of Pre-Lens Tear Film Stability of Daily Disposable Contact Lenses Using Ring Mire Projection</p>

Abstract

Purpose: The primary objective of this study was to evaluate the in vivo pre-lens noninvasive drying-up time of two types of daily disposable contact lenses (DDCLs) after 12 hours of wear. Methods: This prospective, randomized, single-center, cross-over pilot study evaluated 31 subjects aged 18-44 years with normal eyes and good tear film stability who were adapted current soft contact lens wearers. Subjects wore nelfilcon A and stenfilcon A DDCLs for 12 hours each on two different days. Non-invasive video keratography drying-up time (NIK-DUT) videos of each eye were recorded 12 hours after lens insertion for about 25 seconds, with a 5-minute tear film recovery time allowed between video recordings of the right and left eyes to avoid bias. Post-blink time required to reach 15% distortion of the projected rings and the speed of break-up at 15 seconds post-blink were measured at each time point and oneye wettability was determined by ring mire projection under white light illumination. Results: Mean time to reach 15% ring distortion was similar for nelfilcon A (19.25±3.20 sec) and stenfilcon A (20.24±3.02 sec) DDCLs but varied highly among subjects. The mean speed of break-up at 15 sec post-blink was 0.3±0.38% distortion/sec (95% confidence interval [CI] 0.138-0.365% distortion/sec) for nelfilcon A and 0.2±0.23% distortion/sec (95% CI 0.048-0.279% distortion/sec) for stenfilcon A DDCLs. Conclusion: Multifunctional topography allowed the objective evaluation of in vivo prelens tear film stability using ring mire projection. This dynamic method was simple, fast and non-invasive, enabling measurements of NIK-DUT and evaluating wettability over a large area, greater than the optical zone of the contact lens surface, for the entire inter-blink interval.

Evaluation of Celligent® Biomimetic Water Gradient Contact Lens Effects on Ocular Surface and Subjective Symptoms

“…Alpha and beta risks are set at 5% and 20%, respectively. The estimated standard deviation (SD) of the difference was set to 0.45 (based on the SD primary variable study by Marx et al [ 34 ]), and the expected minimum NIBUT difference in front of the camera was set to 0.30 s, followed by the loss at the end. The upward adjustment rate has been fixed at 0.10.…”

Changes in Noncontact Meibography and Noninvasive Tear Break-Up Time Test with Contact Lenses Usage

“…They concluded that multifunctional topography allowed the objective evaluation of in vivo pre-lens tear film stability using ring mire projection. 23 …”

Biomimetic-Engineered Silicone Hydrogel Contact Lens Materials

“…On the corneal surface, tear fluid is used as a lubricant to eliminate resistance during blinking. However, when a contact lens is inserted, the diffusion and movement of tear fluid on the surface are affected, increasing the frictional resistance and affecting the diffusion of oxygen contained in the tear fluid. , These might affect ocular health. It is also assumed that the natural components in the tear fluid can affect the function and properties of contact lenses. , Protein adsorption occurs on the surface of contact lenses within a short period after they are applied, resulting in a decrease in oxygen permeability due to the protein adsorption layer.…”