Purpose: To determine optimal objective, machine-derived variables and variable combinations from Scheimpflug and spectral-domain (SD) OCT imaging to distinguish the clinically unaffected eye in patients with asymmetric keratoconus (AKC) from a normal control population.
Design: Retrospective case-control study.
Participants: Thirty clinically unaffected eyes with no physical findings on slit-lamp examination, no definitive abnormalities on corneal imaging, and corrected distance acuity of 20/20 or better from 30 patients with highly AKC eyes and 60 eyes from 60 normal control patients who had undergone uneventful LASIK with at least 2 years of stable follow-up (controls).
Purpose: To comprehensively review the available published literature for cross-linking in the pediatric population.
Methods: Review of the literature published in English in PubMed.
Results: Two hundred ten publications were considered.
Purpose Of Review: This article describes different strategies for corneal measurements and/or intraocular lens (IOL) calculations and proposes a systematic approach for IOL selection in patients who have undergone laser corneal refractive surgery.
Recent Findings: Corneal measurements and IOL calculations cannot be obtained accurately with the standard measuring technologies and formulas in patients with history of laser corneal refractive surgery; therefore a variety of methods and formulas, some of which required prerefractive surgery data, have been proposed to improve the accuracy of measurements and calculations. Formulas that do not rely on prerefractive data seem to be as accurate as those that do; therefore the lack of prerefractive data no longer presents an obstacle for accurate IOL selection in these patients.
FS-assisted LASIK has become the preferred method for LASIK flap creation due to the precision, accuracy, and reproducibility of the flap creation. Thinner, planar flaps may help prevent cases of post-LASIK ectasia and may have a superior refractive outcome. However, FS flap creation has several unique complications that require early recognition and optimal timely management for the best visual outcomes.
View Article and Find Full Text PDFPurpose: To compare central, regional and relational corneal thickness values obtained with multiple technologies in normal patients and to determine their equivalence and interchangeability.
Methods: Retrospective analysis of 100 eyes from 50 patients evaluated by ultrasound pachymetry (Pachette II), scanning-slit (Orbscan II), Scheimpflug (Pentacam HR) and spectral-domain ocular coherence tomography (OCT) (RTVue-100) obtained as average values (OCT-A) and point measurements (OCT-P). Measurements included central corneal thickness (CCT) for all technologies and thinnest corneal thickness for scanning-slit, Scheimpflug and OCT.
Purpose: To evaluate changes in corneal epithelial and stromal thickness after corneal collagen cross-linking (CXL) in eyes with keratoconus and postoperative corneal ectasia using spectral-domain optical coherence tomography (SD-OCT).
Methods: Anterior segment SD-OCT (RTVue-100; Optovue, Inc., Fremont, CA) was used to compare regional corneal epithelial and stromal thickness in eyes with keratoconus and ectasia before CXL and 1 and 3 months after CXL.
Purpose: To assess corneal microarchitecture and regional epithelial thickness profile in eyes with keratoconus, postoperative corneal ectasia (ectasia), and normal unoperated eyes (controls) using spectral-domain optical coherence tomography (SD-OCT).
Methods: Regional corneal epithelial thickness profiles were measured with anterior segment SD-OCT (Optovue RTVue-100, Optovue Inc., Fremont, CA).
OBJECTIVE To estimate and compare the incidence of operable cataract and the desired cataract surgery rates required to eliminate cataract-related visual impairment in several Latin American settings. METHODS We obtained raw data on age-specific cataract prevalence from standardized population-based surveys. We used the data in a previously described model to estimate the incidence of operable cataract at 11 sites in 10 countries across Latin America.
View Article and Find Full Text PDFPurpose: To compare visual acuity and higher-order aberrations (HOAs) after wavefront-guided and wavefront-optimized laser in situ keratomileusis (LASIK).
Methods: This retrospective study comprised refraction-matched myopic eyes that had wavefront-guided (Visx Star S4 laser) or wavefront-optimized (WaveLight Allegretto Wave laser) LASIK targeted for emmetropia. Preoperative and postoperative manifest refraction spherical equivalent (MRSE), uncorrected (UDVA) and corrected (CDVA) distance visual acuities, and preoperative and postoperative HOAs were compared.
Purpose: To analyze the changes in higher-order aberrations (HOAs) that occur after wavefront-optimized photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).
Setting: Emory Eye Center and Emory Vision, Atlanta, Georgia, USA.
Methods: This retrospective analysis comprised eyes that had PRK or LASIK from June 2004 through October 2005.
Purpose: To determine which of 3 methods for measuring preoperative refractive error yields the best refractive outcomes after wavefront-guided (Visx Star S4) or wavefront-optimized (WaveLight Allegretto Wave) excimer laser in situ keratomileusis (LASIK).
Setting: Emory Eye Center and Emory Vision, Emory University, Atlanta, Georgia, USA.
Methods: This retrospective analysis of LASIK, performed from June to December 2007, analyzed sphere, cylinder, and spherical equivalent (SE) refractions generated from 3 methods (manifest refraction, aberrometer autorefraction [CustomVue WaveScan], corneal analyzer autorefraction [Nidek ARK-10000 OPD]), actual programmed treatment, and absolute deviation from ideal treatment (deviation) for each technique.