TY - JOUR
T1 - Controlled induction of spherical aberration with custom soft contact lenses
AU - Parker, Katrina E.
AU - Marsack, Jason D.
AU - Elswick, James D.
AU - Brunstetter, Tyson J.
AU - Applegate, Raymond A.
PY - 2009/5
Y1 - 2009/5
N2 - Background: This study investigated the non-invasive induction of spherical aberration (SA) levels consistent with complication-free wavefront-guided (WFG) refractive surgery using custom WFG soft contact lenses and quantified the resulting impact on visual performance. Methods: Twelve healthy individuals of typical military age (mean of 26.08 ± 1.92 years) meeting the inclusion criteria of emmetropia (less than ± 0.50 DS and less than ± 0.50 DC) as measured by subjective refraction served as subjects. Five plano lenses were manufactured to induce a range of SA typical of those encountered after refractive surgery. The measured SA values over a 6 mm artificial pupil in these five lenses were -0.224 m, 0.074 m, 0.214 m, 0.495 m and 0.621 m. For each subject, the level of total ocular aberrations through 10 Zernike radial orders over a 6 mm pupil was measured with a custom Shack-Hartmann wavefront sensor, while wearing each lens. Visual performance was evaluated using high contrast visual acuity (HCVA) measured through a 6 mm artificial pupil. Results: Custom WFG soft contact lenses can be manufactured to include the range of SA that occurs with complication-free refractive surgery (-0.20 m to +0.60 m) and produces a change in SA within a similar range when worn on the eye. High contrast visual performance with these lenses varied, depending on the amount of SA in each lens. Visual performance worsened with greater amounts of positive or negative SA and a quadratic fit to the data peaked at +0.209 m. Conclusions: Defined levels of SA can be manufactured and induced (non-invasively) with WFG soft contact lenses and their effect on logMAR high contrast visual performance can be measured. Results show that subjects' best logMAR HCVA occurs with the presence of positive residual SA. When designing the actual test lens, the targeted change in aberrations for each subject will likely be better achieved by first measuring the aberrations of a template lens on the eye and then compensating for unique subject dependent eye-lens interactions.
AB - Background: This study investigated the non-invasive induction of spherical aberration (SA) levels consistent with complication-free wavefront-guided (WFG) refractive surgery using custom WFG soft contact lenses and quantified the resulting impact on visual performance. Methods: Twelve healthy individuals of typical military age (mean of 26.08 ± 1.92 years) meeting the inclusion criteria of emmetropia (less than ± 0.50 DS and less than ± 0.50 DC) as measured by subjective refraction served as subjects. Five plano lenses were manufactured to induce a range of SA typical of those encountered after refractive surgery. The measured SA values over a 6 mm artificial pupil in these five lenses were -0.224 m, 0.074 m, 0.214 m, 0.495 m and 0.621 m. For each subject, the level of total ocular aberrations through 10 Zernike radial orders over a 6 mm pupil was measured with a custom Shack-Hartmann wavefront sensor, while wearing each lens. Visual performance was evaluated using high contrast visual acuity (HCVA) measured through a 6 mm artificial pupil. Results: Custom WFG soft contact lenses can be manufactured to include the range of SA that occurs with complication-free refractive surgery (-0.20 m to +0.60 m) and produces a change in SA within a similar range when worn on the eye. High contrast visual performance with these lenses varied, depending on the amount of SA in each lens. Visual performance worsened with greater amounts of positive or negative SA and a quadratic fit to the data peaked at +0.209 m. Conclusions: Defined levels of SA can be manufactured and induced (non-invasively) with WFG soft contact lenses and their effect on logMAR high contrast visual performance can be measured. Results show that subjects' best logMAR HCVA occurs with the presence of positive residual SA. When designing the actual test lens, the targeted change in aberrations for each subject will likely be better achieved by first measuring the aberrations of a template lens on the eye and then compensating for unique subject dependent eye-lens interactions.
KW - Custom soft contact lens
KW - High contrast visual acuity
KW - Higher-order aberrations
KW - Spherical aberration
KW - Wavefront-guided
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U2 - 10.1111/j.1444-0938.2009.00375.x
DO - 10.1111/j.1444-0938.2009.00375.x
M3 - Article
C2 - 19351378
AN - SCOPUS:67849124649
SN - 0816-4622
VL - 92
SP - 283
EP - 288
JO - Clinical and Experimental Optometry
JF - Clinical and Experimental Optometry
IS - 3
ER -