Klyce ocular

PURPOSE: To derive limits of metric keratoconus indices for classification into keratoconus stages. DESIGN: Validity and reliability analysis of diagnostic tools. METHODS: A total of 126 patients from the keratoconus center of Homburg/Saar were evaluated with respect to Amsler criteria, using Pentacam (Keratoconus Index [KI], Topographic Keratoconus Classification [TKC]), Topographic Modeling System (Smolek/Klyce, Klyce/Maeda), and Ocular Response Analyzer (Keratoconus Match Probability [KMP], Keratoconus Match Index [KMI])...

OBJECTIVES: To report intraoperative and 24-month refractive, topographic, tomographic, and aberrometric outcomes after corneal collagen cross-linking in progressive advanced keratoconus. METHODS: Prospective, nonrandomized single-center clinical study involving 28 eyes. Main outcome measures included uncorrected and best spectacle-corrected visual acuities, sphere and cylinder refraction, topography, tomography, aberrometry, and endothelial cell count evaluated at baseline and follow-up at 1, 3, 6, 12, and 24 months after treatment...

PURPOSE: To report refractive, topographic, tomographic, and aberrometric outcomes 12 months after corneal cross-linking (CXL) in eyes with progressive advanced keratoconus. DESIGN: Prospective, nonrandomized, single-center clinical study. PARTICIPANTS: Twenty-eight eyes undergoing CXL between April and June 2006. INTERVENTION: Riboflavin-ultraviolet A (UVA)-induced CXL included instillation of 0.1% riboflavin-20% dextrane solution 30 minutes before UVA irradiation and every 5 minutes for an additional 30 minutes during irradiation...

PURPOSE: When keratorefractive surgery is used to treat a central corneal diameter smaller than the resting pupil, visual symptoms of polyopia, ghosting, blur, haloes, and glare can be experienced. Progress has been made to enlarge the area of surgical treatment to extend beyond the photopic pupil; however, geometric limitations can pose restrictions to extend the treatment beyond the mesopic pupil diameter and can lead to impediments in night vision. The size of the treated area that has achieved good optical performance has been defined as the functional optical zone (FOZ)...

There is now a wide range of devices available for corneal topographic analysis. Although most devices use the Placido disk approach, fluorescein profilometry, laser holography and scanning slit technology have also been employed. The colour-coded topographical maps have been designed for ease of clinical interpretation. The application of this technology to further our understanding of the effects of contact lens wear and various forms of refractive surgery is demonstrated. Current developments include the merging of corneal topographic analysis and ocular wavefront sensing technology to create the capability of etching sophisticated corneal shapes in the course of refractive surgery so as to provide optimal aberration control...

AIM: We statistically assessed the videokeratographic data obtained from families with keratoconus in order to determine reliable criteria for detecting keratoconus suspects. MATERIAL AND METHODS: Fourteen keratoconus patients from 12 families were enlisted. We investigated 55 relatives (110 eyes). Standard videokeratographic data were obtained by screening 30 individuals (60 eyes) with clinically normal eyes, with no history of ocular disorders, contact lens wear, or keratoconus individuals in their family...

The air/tear interface contributes 70% of the vergence in the eye and, because of this, even minor variations in its shape can produce significant visual deficit. Placido disc-based corneal topographers measure the precise characteristics of the corneal surface, transforming shape into color-coded dioptric power maps and topography indexes related to optical quality and specific patterns associated with pathology. Artificial intelligence-based methods are used to classify corneal topography and these are used as screening tools...

PURPOSE: To describe a case of inferior corneal steepening with a keratoconus-like pattern in a patient with nocturnal lagophthalmos and aqueous tear deficiency (ATD). METHODS: Axial curvature mapping was performed with the Tomey TMS-2N videokeratoscopy instrument. Keratoconus-like topography patterns were identified with the Klyce Software package of this instrument. RESULTS: Axial videokeratoscopy showed asymmetric inferior corneal steepening in the right eye...

BACKGROUND: The nonsuperimposable mirror-image symmetry of the body (enantiomorphism) is reflected in the wavefront error maps of eyes. Averaging the wavefront errors of right and left eyes has the potential to adversely affect correlations made between wavefront error and visual acuity or other factors. Not only are the results of past studies using Zernike terms suspected of being invalid, there is concern about possible errors in the algorithms used to create customized corneal ablations...

PURPOSE: Laser in situ keratomileusis (LASIK) has been associated with the development of postoperative corneal ectasia. We present a case of early onset ectasia after LASIK, review known risk factors in development, and discuss possible strategies for prevention. METHODS: A 39-year-old man underwent bilateral LASIK for moderate myopia. Preoperative cycloplegic refractions were -9.00 + 0.25 x 140 degrees OD and -7.75 sphere OS. Corneal topography demonstrated mild inferior steepening bilaterally although definite evidence of keratoconus by either the Klyce/Maeda and Smolek/Klyce keratoconus screening tests was not present...

PURPOSE: To correlate clinically observed fluctuations in manifest refraction, visual acuity, keratometry, and intraocular pressure (IOP) with changes in the anterior corneal surface as measured by videokeratography in patients 10 years after radial keratotomy (RK). SETTING: Four clinical centers in the United States that participated in the Prospective Evaluation of Radial Keratotomy (PERK) study. METHODS: Thirty-two eyes of 20 PERK patients who noted diurnal fluctuations in vision had clinical examination and videokeratography (TMS-1, Computed Anatomy Inc...

PURPOSE: To investigate whether corneal wavefront aberrations vary with aging. METHODS: One hundred two eyes of 102 normal subjects were evaluated with videokeratography. The data were decomposed using Taylor and Zernike polynomials to calculate the monochromatic aberrations of the cornea for both small (3-mm) and large (7-mm) pupils. RESULTS: For a 3-mm pupil, the amount of total aberrations (Spearman rank correlation coefficient r(s) = 0...

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OBJECTIVE: To compare effectiveness, safety, and stability of excimer laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) for low-to-moderate myopia. DESIGN: Prospective, randomized, bilateral study. PARTICIPANTS: Thirty-three patients with a manifest refraction of -2.50 to -8.00 diopters (D) participated. INTERVENTION: For each patient, one eye received LASIK and the other received PRK. The first eye treated, and surgical method in the first eye, were randomized...

OBJECTIVE: To compare laser in situ keratomileusis (LASIK) with photorefractive keratectomy (PRK) in the correction of myopia from -2.00 to -5.50 diopters. DESIGN: Prospective, randomized, paired clinical trial. PARTICIPANTS: Fifty-two eyes of 26 myopic patients were enrolled in the study. INTERVENTION: Each patient received PRK on one eye (PRK eye) and LASIK on the other (LASIK eye); the procedure assigned to each eye, and the sequence of surgeries for each patient was randomized...

Corneal topography plays an important role in laser in situ keratomileusis (LASIK). Preoperative screening permits the detection of keratoconus and other corneal shape anomalies that may be a contraindication for refractive surgery. Monitoring the progress of the surgical outcome with topography is helpful to detect postoperative complications such as decentration and clinically significant irregular astigmatism. LASIK compares favorably with PRK for the treatment of low to moderate myopia in terms of early achievement of refractive stability, but induction of modest amounts of irregular astigmatism can be a concern...

PURPOSE: Because keratometry readings may no accurately reflect the refractive changes after keratorefractive surgery for myopia, better methods for the assessment of corneal curvature in the postsurgical cornea are needed. METHODS: We developed a procedure to calculate the average central power (ACP) of the cornea within the entrance pupil from videokeratography. Videokeratograph-derived keratometry-style readings (average K; K) and calculated ACPs, as well as the differences between the two values, were compared in four groups: normal corneas (n = 30), corneas with regular astigmatism (n = 30); post-radial keratotomy corneas (RK, n = 85), and post-excimer laser photorefractive keratectomy corneas (PRK, n = 63)...

BACKGROUND: In patients undergoing cataract extraction with PC IOL insertion, pre-op and post-op corneal power measurement is necessary to calculate induced astigmatism. In cases with irregular corneal astigmatism, measurements with traditional keratometry is inaccurate. We report the use of video keratography in three cases that required keratometry readings in order to calculate IOL power. These cases were characterized by irregular or incomplete keratometer mires, so quantitative descriptors derived from computer-assisted corneal topography (TMS-1) were used instead...

Epikeratophakia is based on the principles of the Barraquer refractive procedures, with modifications that simplify the surgical technique and eliminate the use of the microkeratome by placing the donor corneal tissue lens on the anterior surface of the cornea. Procedures developed to permit freeze-drying the preshaped lens for storage enable these lenses to be obtained from a central source, freeing the surgeon from the complexities of the computer and the cryolathe. The correction of theoretically unlimited amounts of myopia is possible with these lenses...

No abstract text is available yet for this article.