PURPOSE To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. METHODS 120 eyes of 60 patients underwent phacoemulsification. In patients' eyes, an aberration-free IOL (Aspira-aA; Human Optics) or an aberration-correcting aspherical IOL (Tecnis ZCB00; Abott Medical Optics) was randomly implanted. After surgery, contrast sensi...

PURPOSE To evaluate the efficacy, safety, predictability, and visual performance of excimer laser photorefractive keratectomy (PRK) for myopia greater than -8 diopters (D). METHODS Fifty-four patients (104 eyes) with myopia from -8D to -13D and cylinder up to -4D received surface ablation technique with the Allegretto wave version 1009-1 excimer laser to correct their refractive error. The pa...

PURPOSE To assess wavefront derived refraction and full eye biometry including ciliary muscle dimension and full eye axial geometry in pseudophakic eyes using spectral domain OCT equipped with a Shack-Hartmann wavefront sensor. METHODS Twenty-eight adult subjects (32 pseudophakic eyes) having recently undergone cataract surgery were enrolled in this study. A custom system combining two optica...

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....

H uman eyes are capable of six types of movement: x/y lateral shifts, z levelling, horizontal and vertical rotations, and cyclotorsion (rotation around the optical axis). Current laser technology for refractive surgery creates corneal alterations to correct refractive errors more accurately than in the past.1 Ablation profiles are based on the removal of tissue lenticules through sequential las...

A reliable and objective method to measure aberration changes due to the tear film is essential in improving clinical assessment of the tear film and in vivo retinal imaging. The tear film of 11 subjects are studied by acquiring continuous wavefront measurements in real-time with a customized Shack-Hartmann wavefront sensor. The device has a high resolution lenslet array (190 mum) and a topogra...

PURPOSE To evaluate the theoretical influence of the change in corneal asphericity (ΔQ) on the change in fourth-order Zernike spherical aberration coefficient (ΔC(4)0) with customized aspheric refractive correction of myopia and hyperopia. METHODS The initial anterior corneal surface profile was modeled as a conic section of apical radius of curvature R0 and asphericity Q₀. The postoperative ...

Simultaneous wavefront measurements are planned at the 6.5 m MMT telescope of five dynamically refocused Rayleigh laser beacons (RLGS) and a bright natural star to demonstrate tomographic wavefront reconstruction. In this paper, we summarize preliminary data recorded from the five laser beacons during the first telescope run at the MMT in June 2004. Beam projection is from behind the secondary ...