Surface Refractive Index Shift of Kalifilcon A Compared With Dailies Total1 and Precision1 Lenses

Evaluation of Surface Refractive Index Shift and Lens Absorption / Adsorption of Tear Components of Commercially Available Kalifilcon A Lenses Compared to Dailies Total1 and Precision1

This was a single-site, bilateral, repeated-measures insertion study in habitual soft contact lens wearers. Ten participants were enrolled. All participants attended a Screening/Dispensing Visit at which informed consent was obtained and eligibility was assessed. Eligible participants then wore each of three commercially available daily disposable soft contact lens types - kalifilcon A (Bausch + Lomb), Dailies Total1 (delefilcon A, Alcon) and Precision1 (verofilcon A, Alcon), all -3.00 D - bilaterally for wear times of 0.5, 1, 3, 5 and 10 minutes over a total of 6 study visits. A new lens pair was inserted for each wear time, with a 3-5 minute washout period between lens pairs. Immediately following removal, the right-eye lens was measured for surface refractive index on a Metricon M-2010 Prism Coupler.

Rationale: earlier work (ROC2-20-012) showed a change in surface refractive index for Dailies Total1 (delefilcon A) and Precision1 (verofilcon A) lenses after 5 minutes of wear, attributed to a change in surface water content. ROC2-21-007 was designed to determine whether that change occurs in less than 5 minutes. Three study lenses (one test, two controls) were each worn bilaterally. Wear times of 0.5, 1 and 3 minutes were completed at one visit and 5 and 10 minutes at another visit for each lens type, giving 6 visits of approximately 30 minutes each, each on a separate day; the clinical investigation took approximately 2 weeks. Lens type order followed the study randomization schedule prepared before enrolment by an unmasked statistician not otherwise involved in the study; unmasked study personnel dispensed and collected study materials so that the participant and Investigator remained masked. Endpoint: surface refractive index of the worn right-eye lens, measured on a Metricon M-2010 Prism Coupler, compared with unworn (baseline) values for the same lens types. Continuous data were summarized with n, mean, standard deviation, median, minimum and maximum, and paired t-tests were used to compare unworn with worn values, with p < 0.05 considered statistically significant.

Inclusion Criteria:

1. Be 18 years or older and have full legal capacity to volunteer.
2. Have physiologically normal anterior segments not exhibiting clinically significant biomicroscopy findings.
3. Have no active ocular disease or allergic conjunctivitis.
4. Not be using any topical ocular medications.
5. Be willing and able to follow instructions.
6. Have signed a statement of informed consent.

Exclusion Criteria:

1. Participating in a conflicting study in the opinion of the Investigator.
2. Considered by the Investigator to not be a suitable candidate for participation.