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Christiane Müller,1 Sebastian Marx,1,2 Julia Wittekind,2 Wolfgang Sickenberger2,3 1Jenalens Kontaktlinsenstudio GmbH, Jena, Germany; 2JenVis Research c/o Ernst-Abbe University of Applied Sciences Jena, Jena, Germany; 3Department of Optometry & Vision Science, Ernst-Abbe University of Applied Sciences Jena, Jena, GermanyCorrespondence: Sebastian MarxJenVis Research c/o Ernst-Abbe University of Applied Sciences Jena, Carl-Zeiss-Promenade 2, Jena 07745, GermanyTel +49 3641 205870Email s.marx@jenvis-research.comPurpose: To subjectively evaluate the in vivo tear film stability of three daily disposable contact lenses (DDCLs) using placido ring reflection at lens wear times of 5mins and 8 and 12hrs.Patients and Methods: This prospective, randomized, observer-masked, 3-way crossover study evaluated 28 subjects with good tear film stability. In vivo tear film stability was assessed for three DDCLs (nelfilcon A, etafilcon A, omafilcon A) on three different days over 12hrs of lens wear. Time to first distortion by non-invasive keratography drying-up time (NIK-DUTf) was assessed by reviewing the captured videos. Lens wettability was also graded subjectively by three investigators using a scale from 0 (no visible distortions) to 3 (distortions in more than one-third of the ring reflection zone). Medians were analyzed statistically.Results: Mean NIKDUTf at 8hrs was longer for nelfilcon A and shorter for etafilcon A and omafilcon A, but the differences were not significant. NIK-DUTf did not differ significantly among nelfilcon A, etafilcon A and omafilcon A DDCLs at all visits (p=0.36). Subjective wettability grades after 5mins, 8hrs, and 12hrs differed significantly for etafilcon A (P < 0.01) and omafilcon A (p < 0.01), but not for nelfilcon A (p = 0.05), DDCLs.Conclusion: Grading was sufficiently sensitive to differentiate the wettability performances of the three lens materials. Nelfilcon A maintained wettability over the wearing period, whereas etafilcon A material showed faster dewetting at 8 and 12hrs than at 5mins after lens insertion.Keywords: pre-lens tear film stability, wettability, NIK-DUT, drying-up time, daily disposable contact lenses, Keratograph 5M |
