purpose: to investigate the effects of surface ablation excimer surgery on higher-order aberrations and to assess the safety and efficacy of wavefront-guided surface ablation excimer surgery in patients with hyperopia and hyperopic astigmatism. methods: in this analytical & descriptive study, wavefront-guided surface ablation excimer surgery was performed in 58 eyes of 31 patients with hyperopi...

purpose : to describe a distinctive pattern of induced higher order aberration (hoa) after lasik for mixed astigmatism case reports : wavefront-guided lasik with iris recognition and eye tracking (excimer laser: technolas 217z apt protocol microkeratome: moria cb) was performed in six eyes with moderate to high mixed astigmatism for a nominal optical zone of 6.3 mm. the patients were re-examine...

PURPOSE To identify an optimal customized ablation strategy in the treatment of eyes with secondary irregular astigmatism. METHODS Corneal anterior surface elevation maps of 50 eyes with secondary irregular astigmatism after decentered laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) and 50 virgin eyes were used for customized ablation simulations. Two ablation simula...

this work is a report 0/9 cases ofarcuate incision for correction 0/astigmatism, after penetrating keratoplasty. plannings were based ojj corneal topography, and the first operation was always arcuate incision alone. 11,e secondary plans were based on refractive errors. the mean of preoperative astigmatism was 6d with the range of5 to 9/). after arcuate incision a/the graft-host interface in th...

BACKGROUND The purpose of this paper is to report the successful treatment of corneal scarring and high corneal astigmatism secondary to previous pterygium surgery with diamond burr superficial keratectomy using mitomycin C. METHODS Four patients with corneal scarring and high corneal astigmatism related to previous pterygium surgery underwent diamond burr superficial keratectomy with applica...

PURPOSE To determine the impact of higher-order monochromatic aberrations on lower-order subjective sphero-cylindrical refractions. METHODS Computationally-aberrated, monochromatic Sloan letters were presented on a high luminance display that was viewed by an observer through a 2.5mm pupil. Through-focus visual acuity (VA) was determined in the presence of spherical aberration (Z40) at three ...

The eye's optical components are imperfect and cause distortions in the retinal image that cannot be corrected completely by conventional spectacles. It is important to understand how these uncorrected aberrations (those excluding defocus and primary astigmatism) affect visual performance. We assessed reading performance using text with a simulated monochromatic aberration (defocus, coma, or se...

Postoperative visual acuity can be limited by post-keratoplasty astigmatism, even with a clear corneal graft. Astigmatism management can be performed by selective suture removal, adjustment of sutures, optical correction, photorefractive procedures, wedge resection, intra-ocular lens implantation, intracorneal ring segments, relaxing incisions with or without compression sutures and repeated ke...

The changes of higher-order aberrations (HOAs) after bilateral lateral rectus muscle recession were evaluated. Forty eyes of 20 children were enrolled and their wavefront information was assessed until postoperative 3 months. Even though the root mean square (RMS) of total aberration was not changed, the RMS of HOA was transiently increased at postoperative 1 week and returned to baseline level...