PURPOSE To demonstrate how using the Wavelight Contoura measured astigmatism and axis eliminates corneal astigmatism and creates uniformly shaped corneas. PATIENTS AND METHODS A retrospective analysis was conducted of the first 50 eyes to have bilateral full WaveLight® Contoura LASIK correction of measured astigmatism and axis (vs conventional manifest refraction), using the Layer Yolked Redu...

PURPOSE Astigmatism is a very common refractive error in humans, but its etiology is poorly understood. The primary purpose of this study was to determine whether alterations in visual experience would result in astigmatism in chicks. METHODS Longitudinal and cross-sectional data were obtained from chicks that were raised undergoing four different visual manipulations known to alter axial eye...

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...

Purpose. To compare the surgically induced astigmatism from clear corneal and square posterior limbal incisions at the time of cataract surgery. Methods. Surgically induced astigmatism was calculated for a set of eyes after cataract surgery using a temporal 2.2 mm square posterior limbal incision. Results were compared to similar available data from surgeons using clear corneal incisions of sim...

Purpose: To evaluate the safety and efficacy of limbal relaxing incisions (LRIs) for corneal astigmatism correction during phacoemulsification Methods: 24 eyes of 24 patients with the mean age of 65.71 years (range: 55 to 83 years) with senile cataracts and mean corneal astigmatism of 1.9±0.83 diopters (D) (range: 1.5 to 3.5 D) were included in this study. All LRIs were performed during phacoem...

SEPTEMBER 2011 CATARACT & REFRACTIVE SURGERY TODAY EUROPE 89 N umerous factors make the treatment of corneal astigmatism with laser corneal surgery more challenging than treatment of spherical error alone. Astigmatism can be irregular and complex, and it can be compounded by myopic or hyperopic error. Each scenario requires choice of an appropriate treatment approach. Choosing the wrong treatme...

PURPOSE To investigate the effect of the degree of astigmatism on optical quality in children. The important objective evaluation parameters we focus on include the RMS of the high-order aberrations, MTF, and PSF. METHODS The children, age ranging from 7 to 10 years old, underwent an optometry examination. Fifty-nine children who met the inclusion criteria were divided into three groups: A (1...

BACKGROUND To establish clinical expectations when using the Lenstar LS 900® dual-zone automated keratometer for surgery planning of toric intraocular lenses. METHODS Fifty eyes were measured with the Lenstar LS 900® dual-zone automated keratometer . Surgical planning was performed with the data from this device and the known surgically induced astigmatism of the surgeon. Post-operative refra...

PURPOSE The purpose of this study was to examine the prevalence of astigmatism and poor visual acuity and rate of eyeglass wear in grade school children who are members of a Native American tribe reported to have a high prevalence of large amounts of astigmatism. METHODS Vision screening was conducted on 1,327 first through eighth grade children attending school on the Tohono O'odham Reservat...