|Title||Impact of Soft Contact Lens Design on On-eye Residual High Order Aberrations|
|Author, Co-Author||A Philip Aitsebaomo, Harold Bedell|
|Abstract|| Purpose: This study evaluated the impact of soft spherical contact lens properties on residual High Order Aberrations (rHOA) in adapted soft contact lens wearers. Reduction in rHOA is expected to correlate with improvements in low contrast visual acuity (VA), presumably addressing a significant safety concern of nighttime driving in the population, as reduction of HOA might result in improved night vision.
Methods: Twelve adapted soft spherical contact lens wearers (ages 18 to 33; 9 females, 3 males; 24 eyes) were consented for the study. Test articles include: Alcon Dailies Total 1 (DT1), Johnson & Johnson Acuvue Oasys (Oasys), Cooper Vision Biomedics 55 Premier (Premier), and Bausch & Lomb Pure Vision 2 (PV2) spherical contacts. Lenses differ in asphericity, water content, material, and modulus. Subjects wore each set of lenses in a random order, and HOAs up to Z27 were measured without lenses and through each lens with an Abbott Medical WaveScan Aberrometer after allowing at least 5 minutes for settling. Pupil diameter ranged from 5 to 7mm. Low (10%) contrast VA was measured with a Precision Vision illuminated SLOAN letter chart. Spherical Aberration (SA), Root Mean Square (RMS) and VA were analyzed for differences in performance among contact lenses.
Results: Repeated-measures ANOVA showed that all of the lenses had significantly less positive SA than the no-lens condition (p=0.001). Both DT1 and Premier lenses had less residual SA than the other lenses, improving VA by about 3 letters (p<0.02). There was no significant difference between DT1 and Premier in the parameters measured. Similarly, there was no significant difference in the performance of Oasys and PV2. There were no significant changes in RMS across lens type (p=0.185) or in the no-lens vs lens condition.
Conclusion: DT1 and Premier lenses, both of which have aspheric design and a low modulus, produce low residual SA and yield better low-contrast VA in a sample of young subjects. Although PV2 also has an aspheric design, performance of this high modulus lens is similar to the Oasys, a low modulus spherical design lens. All of the lenses tested showed similar RMS on the eye.
|Affiliation of Co-Authors||University of Houston College of Optometry|