Using ZernikeTool software, the polychromatic point-spread function with Stiles-Crawford effect was calculated for residual ocular higher-order aberrations (HOAs) (3rd to 6th order) for 4.0 mm and 6.0 mm pupils and defocus of 0.00 diopter (D), -0.50 D, and +0.50 D. The IOL spherical aberration at which
maximum image quality was achieved was determined. Stepwise multiple regression analysis was performed to assess the predictors of optimum IOL spherical aberration.
RESULTS: With 0.00 D, -0.50 D, and +0.50 D defocus, respectively, the mean optimum IOL spherical aberration (6.0 mm) ranged from -0.49 to -0.42 p.m, -0.22 to -0.18 pm, and -0.75 to -0.64 pm (6.0 mm pupil) and from -0.34 to -0.20 mu m, +0.08 to +0.44 pm, and -1.12 to -0.83 mu m (4.0 selleck chemicals llc mm pupil). Of the Zernike terms check details that significantly predicted optimum IOL spherical aberration, 4th-order spherical aberration Z(4,0) made
the greatest contribution, followed by the 6th-order spherical aberration Z(6,0).
CONCLUSION: The amount of IOL spherical aberration producing the best image quality after previous myopic wavefront-guided PRK varied widely and could be predicted based on the full spectrum of corneal HOAs.”
“Study Design. Measurement (validity) study.
Objective. Examine validity and reproducibility of self-report measures of walking capacity for use in patients with lumbar spinal stenosis (LSS).
Summary of Background Data. Treatment outcomes in patients with LSS are often determined using data from self-report questionnaires. Despite some validity evidence available to support the use of self-report instruments in the evaluation of walking capacity Dactolisib supplier in LSS, it is not certain that the construct being tapped using any of the self-report measures is, in fact, walking capacity.
Methods. Validity of the Physical Function Scale of the Swiss Spinal Stenosis
Questionnaire, the Oswestry Disability Index (ODI), self-predicted walking capacity (distance in meters) and a number of single item walking capacity questions was evaluated through comparison with a criterion measure of walking capacity, the Self-Paced Walking Test, in patients with LSS. Test-retest reproducibility was also examined for each of the self-report measures.
Results. Subjects included 49 patients (65.8 +/- 10.0 years of age) with LSS confirmed on imaging and by a spine specialist surgeon. The measures found to be most highly associated with the criterion Self-Paced Walking Test were the walking distance item from the ODI (r = 0.83) and self-reported walking capacity in meters (with the aid of a distance reference) (r = 0.80). Reported walking capacity in meters had the lowest test-retest reproducibility (intraclass correlation coefficient = 0.65) of the measures studied.
Conclusion. This study provides new information to help guide health professionals and researchers in the selection of appropriate outcome tools when examining walking in an LSS population.