Evaluation of Keratometry With a Novel Color-LED Corneal Topographer (original) (raw)
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Clinical ophthalmology (Auckland, N.Z.), 2015
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Case reports in ophthalmology, 2014
This case report aims to evaluate safety, efficacy and feasibility of anterior surface imaging by a novel point-source reflection topographer, in comparison to four other corneal imaging modalities. A 17-year-old female patient, clinically diagnosed with chronic herpetic keratitis in her left eye was imaged by a novel multicolored-spot reflection topography system. We comparatively investigated elevation and curvature maps between the novel topographer and established Placido disk topography and Scheimpflug tomography systems. Pachymetry maps were compared between the Scheimpflug system and anterior-segment optical coherence tomography system. The Placido system failed to properly register the abnormal anterior surface due to incomplete mire registration, while the Scheimpflug topometry device imaged the anterior surface properly, but not the posterior (due to media opacity), and thus pachymetry was highly irregular and erroneous in this case. Imaging of corneas infected with herpes...
Middle East African Journal of Ophthalmology, 2015
To compare Orbscan II and Pentacam keratometry readings in terms of their agreement with a manual Javal type keratometer Methods: In this retrospective study, records of patients who had refractive surgery were reviewed. We extracted data of 765 eyes which had keratometry with the Javal keratometer; of these, 577 had Orbscan II and 200 eyes had Pentacam acquisitions. Minimum (min-K) and maximum (max-K) keratometry readings and keratometric astigmatism with the latter two devices were compared with Javal.
Comparison of Corneal Powers Obtained from 4 Different Devices
American Journal of Ophthalmology, 2009
To assess the repeatability and comparability of anterior corneal power values obtained from the Galilei Dual Scheimpflug Analyzer (Ziemer, Port, Switzerland), Humphrey Atlas corneal topographer (Carl Zeiss, Jena, Germany), IOLMaster (Carl Zeiss), and a manual keratometer (Bausch & Lomb Inc, Rochester, New York, USA). • DESIGN: Prospective, comparative study. • METHODS: Prospectively, 20 subjects were enrolled. Three sets of corneal power measurements were obtained by a single observer using the Galilei, Atlas topographer, IOLMaster, and manual keratometer. Repeatability of the 3 measurements from each device was evaluated by means of coefficient of variation, standard deviation (SD), and intraclass correlation coefficient. An analysis of variance was used to compare the differences in corneal powers among devices. The Bland and Altman method also was performed to assess agreement in measurements between devices. Vector analysis was used to compare the astigmatism values obtained from different devices. • RESULTS: For each device, the coefficient of variation of repeated measurements was lower than 0.22%. The SD of 3 repeated measurements ranged from 0.042 to 0.096 diopters (D). The intraclass correlation coefficients were higher than 0.99 in all devices. Mean central corneal powers were 43.80 D, 43.88 D, 43.92 D, and 43.76 D for the Galilei, Atlas, IOLMaster, and manual keratometer, respectively. SDs of the differences between devices ranged from 0.07 D for Galilei and IOLMaster to 0.14 D for Galilei and Atlas. For astigmatism, the mean astigmatism values for the Galilei, Atlas, IOLMaster, and manual keratometer were 0.54 D at 84 degrees, 0.51 D at 88 degrees, 0.62 D at 88 degrees, and 0.52 D at 87 degrees, respectively. • CONCLUSIONS: The corneal power measurements from these 4 devices were highly reproducible, comparable, and correlated.
Journal of Cataract & Refractive Surgery, 1992
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Stray-light measurements in keratoconic and cross-linked corneas
Will present methodology and pearls in evaluating corneal ectasia and keratoconus diagnosis and progression assessment based on a multitude of contemporary anterior segment imaging modalities (Scheimpflug imaging, Placido Topography, Cornea Rigidity visualization, Anterior-Segment Optical Coherence Tomography Corneal and Epithelial Imaging, ocular Stray-light quantifier, and novel Multicolored-spot reflection topography). Objective: Attendees will share our extensive and long experience in diagnosing ectasia and progressive keratoconus by employment of new anterior-segment imaging modalities, also applicable to post-surgery follow up and assessment. Outline: 1. Diagnosis and Classification of Keratoconus by Anterior-Segment Imaging: Current status and recent developments 2. Scheimpflug imaging indices based on anterior-surface irregularity 3. Cornea Visualization rigidity measurements (CorVis) 4. Anterior-Segment OCT indices based on cornea asymmetry and focal thinning 5. Epithelial thickness indicators based on 3-dimensional display 6. Novel Multicolored-spot reflection topography 7. Imaging of cross-linked corneas: Pearls and Alerts 8. Atomic-Microscopy imaging in keratoconic and cross-linked corneas 9. Corneal thickness imaging limitations 10. Stray-light measurements in keratoconic and cross-linked corneas
International journal of ophthalmology, 2013
To evaluate the measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients. A hundred and one eyes of 55 keratoconus patients were enrolled in this study. The mean age was 26.2±8.9 years. The inclusion criteria were keratoconus stage I to III according to the Amsler-Krumeich keratoconus classification. All the measurements were done by the same operator, under the mesopic light condition and repeated with three different optical methods; Visante, Orbscan and Pentacam. The evaluated anterior segment parameters were anterior chamber depth (ACD), central and thinnest corneal thickness (CCT and TCT) and pupil diameter (PD). THE MEAN CCT MEASURED BY VISANTE, ORBSCAN AND PENTACAM WERE AS FOLLOWS: 462.0±48.1µm, 463.9±60.9µm, 476.5±45.3µm, respectively (P=0.873). The mean ACD values were 3.34±0.33mm, 3.26±0.33mm, 3.49±0.40mm, respectively (P=0.118). The mean PD measurements were 5.11±1.14mm, 4.80±0.85mm, 3.80±1.38mm, respectively (P...