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DM Robertson, NE Leach, JA Perrigin, DM Perrigin, JP G Bergmanson; In Vivo Wavefront Analysis of A Disposable Hydrogel Multifocal Contact Lens . Invest. Ophthalmol. Vis. Sci. 2002;43(13):3101.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: The purpose of this study is to measure the aberrations induced by soft multifocal contact lenses using ray tracing technology and to compare the visual performance of two different designs (CIBA Focus Progressive and the Acuvue Bifocal) based on visual acuity, pupil size and patient preference. Methods:Twenty well-adapted soft multifocal contact lens wearers were selected. Spherical equivalent refractive errors ranged from -6.87 D to +4.87 D with a mean astigmatic value of -0.39 D. Subjects were successfully re-fitted into the opposing lens design. Lenses were then selected at random and dispensed. At two weeks, ray tracing of the eye/lens system (CIBA Progressive) and the unaided eye was performed using a TRACEY Visual Function Analyzer. Each subject underwent assessment of high and low contrast visual acuity at distance and near, photographic documentation of pupil size, and completion of a patient satisfaction questionnaire. The second pair of lenses were dispensed and the subject returned in two weeks to repeat measurements. Results:There was a significant difference in overall RMS wavefront error between the eye and the eye/lens system (p=0.05). Defocus (Z4) was the most affected with a 2.5 fold reduction in absolute RMS value in the eye/lens system. There was a significant increase in the percentage of higher order aberrations (Z6 - Z27) in the eye/lens system (p=0.05). This increase was demonstrated in the terms for coma and spherical aberration. There was no significant difference in logMAR visual acuity between lenses. Low contrast visual acuity was significantly reduced at both distance and near (p=0.000). Mean pupil size was 3.85 mm. At near, visual acuity decreased with increased pupil size (r2=0.28). On the questionnaire, patients favored CIBA in nine of the eleven categories. Conclusion:Hydrogel multifocal lenses induce higher order aberrations which may explain a loss of contrast and compromised visual acuity. Pupil size was demonstrated to have an affect on visual acuity at near. While CIBA Progressive was preferred overall, there was no statistically significant difference between lenses.
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