Clinical Optometry (Jan 2018)

Effects of relative negative spherical aberration in single vision contact lens visual performance

  • Kho D,
  • Fedtke C,
  • Tilia D,
  • Diec J,
  • Sha J,
  • Thomas V,
  • Bakaraju RC

Journal volume & issue
Vol. Volume 10
pp. 9 – 17

Abstract

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Danny Kho,1 Cathleen Fedtke,1,2 Daniel Tilia,1,2 Jennie Diec,1 Jennifer Sha,1 Varghese Thomas,1 Ravi C Bakaraju1,2 1Brien Holden Vision Institute, Clinical Trial Research Centre, Sydney, NSW, Australia, 2School of Optometry and Vision Sciences, University of New South Wales, Sydney, NSW, Australia Objective: The study aimed to compare the visual performance of contact lenses with and without negative spherical aberration (SA) over 5 days of wear. Methods: At baseline, 32 myopic participants (aged 18–33 years) were fitted in a randomized order with two lenses (test lens with minimal or no SA and 1-Day Acuvue Moist designed with negative SA) for 5 days (minimum 6 hours wear/day). Participants returned for a follow-up visit. This consisted of on-axis SA measurements; high- and low-contrast visual acuities at 6 m; high-contrast acuities at 70 and 40 cm; low-illumination, low-contrast acuity at 6 m; stereopsis at 40 cm; horizontal phorias at 3 m and 33 cm; and ±2.00 D monocular accommodative facility at 33 cm. Participants also rated (1–10 scale) vision quality (clarity and lack of ghosting for distance, intermediate, near, driving vision and vision stability during day- and night-time), overall vision satisfaction, ocular comfort, and willingness to purchase (yes/no response). Results: 1-Day Acuvue Moist induced significantly (p<0.05) more negative SA at distance (∆=0.078 μm) and near (∆=0.064 μm) compared to the test lens, for a 6 mm pupil. There were no significant differences (p>0.05) in acuity, binocular vision, and all subjective metrics except vision stability between lenses where the test lens was rated to provide more stable vision (p<0.05). Conclusion: Contrary to expectations, incorporating negative SA in single vision soft contact lenses did not improve visual performance in non-presbyopic adult myopes. Keywords: soft contact lens, spherical aberration, power profile, visual acuity

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