A 33-year-old man seeking refractive surgery presented with refractive error of -1.75 -4.0×20° in the right and -0.75 -2.5×170° in his left eye in January 2009; best spectacle-corrected visual acuity (BSCVA) was 20/25+ and 20/20respectively. All ocular examinations were unremarkable and family history for keratoconus was negative. He had previously obtained consultation for refractive surgery i...

Reply: We would like to thank Cheng et al. for their comments. The Zywave unit used by them (commercial software 5.09) is different from the one used in our study (software 4.45SP2). Using the pupillometry function, software 5.09 has no fixation target light and the infrared laser runs continuously at 2 mW of power during the measurement. Software 4.45SP2 has no fixation target light, and the i...

PURPOSE To compare the measurements of lower and higher order aberrations (HOA) of 4 commonly used aberrometers. SETTING Massachusetts Eye & Ear Infirmary, Boston, USA. DESIGN Prospective, cross-sectional study, in a controlled, single-blinded fashion. METHODS Multiple readings were obtained in 42 eyes of 21 healthy volunteers, at a single visit, with each of the following aberrometers: A...

Methods: Wavefront aberrations were measured with wavefront aberrometry (ZyWave, Technolas Perfect Vision) on 1509 patients (57.9% females) with a mean age of 43.1 ± 12.0 years (range 18 to 71). We modeled the association of 15 pupil size adjusted (PSA) Zernike polynomials (3rd to 5th order) with age and refractive error using linear regression. A statistical method called clustering of linear ...

Reply: We would like to thank Cheng et al. for their comments. The Zywave unit used by them (commercial software 5.09) is different from the one used in our study (software 4.45SP2). Using the pupillometry function, software 5.09 has no fixation target light and the infrared laser runs continuously at 2 mW of power during the measurement. Software 4.45SP2 has no fixation target light, and the i...

Higher order optical aberrations were measured in 273 cyclopleged Singaporean school children using a Bausch and Lomb Zywave aberrometer, with 268 of these subjects also undergoing corneal topography measurements (Tomey TMS 2 system). Subjects with low myopia (> -3.00 to -0.50 D) showed slightly, but significantly, less positive levels of spherical aberration than other refractive error groups....

PURPOSE To evaluate the correlation between refractive, corneal, and residual astigmatism and higher order aberrations (HOA) in refractive surgery candidates. METHODS Three hundred and seventy-five eyes of 188 patients aged 28.2 ± 6.24 years with a predominance of females (62.7%) were enrolled in this study. Refraction, topography (Orbscan IIz, Bausch & Lomb, Rochester, NY, USA), and aberrome...