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Wang L, Shao X, Fu JL, Hu JJ, Zhou KJ, Li R, Yu AY. Repeatability and Agreement of 4 Biometers Measuring Corneal Astigmatism in Eyes With Irregular Corneal Astigmatism Component. Am J Ophthalmol 2024; 265:200-212. [PMID: 38719132 DOI: 10.1016/j.ajo.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 05/01/2024] [Accepted: 05/01/2024] [Indexed: 06/04/2024]
Abstract
PURPOSE To investigate the repeatability and agreement of corneal astigmatism measurements in eyes with irregular corneal astigmatism component (ICAC) using four devices: IOLMaster 700 biometer, Lenstar 900 biometer, iTrace, and Pentacam. DESIGN Prospective cross-sectional reliability analysis. METHODS Sixty-four eyes (52 patients) with ICAC were examined three times using the four devices. The eye with ICAC in this study is defined as the cornea has a certain degree of irregular astigmatism (asymmetric and/or skewed bowtie pattern of corneal topography according to corneal topography classification), accompanied with total corneal higher-order aberrations in the 4 mm zone of 0.3 µm or greater. Corneal astigmatism was evaluated using three categories: anterior corneal astigmatism (ACA), posterior corneal astigmatism, and total corneal astigmatism (TCA). The repeatability was determined using the ∆Ast (arithmetic mean of vector differences among three repeated corneal astigmatism measurements). Bland-Altman plots and astigmatism vector analyses were employed to assess agreement. RESULTS The IOLMaster 700 (∆Ast = 0.27 ± 0.20 D) showcased higher repeatability in ACA measurements compared to iTrace (∆Ast = 0.37 ± 0.38 D, P = .040) and Pentacam (∆Ast = 0.50 ± 0.22 D, P < .001), and paralleled the performance of Lenstar 900 (∆Ast = 0.31 ± 0.26 D, P = .338). The Pentacam (∆Ast = 0.09 ± 0.07 D, P < .001) demonstrated superior repeatability in posterior corneal astigmatism, whereas the IOLMaster 700 (∆Ast = 0.33 ± 0.23 D, P < .001) excelled in TCA. The IOLMaster 700 exhibited good agreement with either Lenstar 900 or iTrace, characterized by narrow 95% limits of agreement and clinically acceptable vector differences. Conversely, vector differences between Pentacam and the other three devices in ACA and TCA measurements were clinically significant, exceeding 0.50 D (all P < .05). CONCLUSIONS In terms of repeatability of corneal astigmatism measurements in eyes with ICAC, the IOLMaster 700 and Lenstar 900 outperformed iTrace and Pentacam. While the IOLMaster 700 can be used interchangeably with either Lenstar 900 or iTrace, the Pentacam is not interchangeable with the other three devices.
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Affiliation(s)
- Lan Wang
- From the National Clinical Research Center for Ocular Diseases, Eye Hospital (L.W., X.S., J.L.F., J.J.H., K.J.Z., R.L., A.Y.Y.), Wenzhou Medical University, Wenzhou, China
| | - Xu Shao
- From the National Clinical Research Center for Ocular Diseases, Eye Hospital (L.W., X.S., J.L.F., J.J.H., K.J.Z., R.L., A.Y.Y.), Wenzhou Medical University, Wenzhou, China
| | - Jin-Ling Fu
- From the National Clinical Research Center for Ocular Diseases, Eye Hospital (L.W., X.S., J.L.F., J.J.H., K.J.Z., R.L., A.Y.Y.), Wenzhou Medical University, Wenzhou, China
| | - Jing-Jing Hu
- From the National Clinical Research Center for Ocular Diseases, Eye Hospital (L.W., X.S., J.L.F., J.J.H., K.J.Z., R.L., A.Y.Y.), Wenzhou Medical University, Wenzhou, China
| | - Kai-Jing Zhou
- From the National Clinical Research Center for Ocular Diseases, Eye Hospital (L.W., X.S., J.L.F., J.J.H., K.J.Z., R.L., A.Y.Y.), Wenzhou Medical University, Wenzhou, China
| | - Ran Li
- From the National Clinical Research Center for Ocular Diseases, Eye Hospital (L.W., X.S., J.L.F., J.J.H., K.J.Z., R.L., A.Y.Y.), Wenzhou Medical University, Wenzhou, China
| | - A-Yong Yu
- From the National Clinical Research Center for Ocular Diseases, Eye Hospital (L.W., X.S., J.L.F., J.J.H., K.J.Z., R.L., A.Y.Y.), Wenzhou Medical University, Wenzhou, China; National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital (A.Y.Y.), Wenzhou Medical University, Wenzhou, China.
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Barrio AR, Antona B, Morago-Villanueva S, Martínez-Arribas V, González-Pérez M. Intrasession repeatability and agreement of the anterior corneal assessment provided by a multidiagnostic device. Clin Exp Optom 2024:1-7. [PMID: 38494447 DOI: 10.1080/08164622.2024.2324978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 02/23/2024] [Indexed: 03/19/2024] Open
Abstract
CLINICAL RELEVANCE Multidiagnostic systems have recently appeared on the market. Knowledge of the repeatability and validity of any instrument is mandatory before its introduction in clinical practice. BACKGROUND The aim of this work is to examine the intrasession repeatability of anterior pole measurements provided by the multidiagnostic device Wave Analyzer Medica 700 (WAM700) and agreement with Pentacam measurements in normal eyes. METHODS In the right eyes of 113 participants, three repeat measurements of central keratometry, central corneal thickness, anterior chamber depth and corneal eccentricity were made with the WAM700 and Pentacam in random order. Intrasession repeatability and agreement were determined. RESULTS Employing WAM700, intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth was good (ICCs ≥ 0.992; CV 0.48-0.98%), yet worse than the values obtained for the Pentacam (ICCs ≥ 0.998; CV 0-0.33%). WAM700 showed excellent intrasession repeatability when used to measure the anterior chamber depth (Sw 0.03 mm). However, the repeatability of this device was inferior for central corneal thickness (Sw 4.24 μm) and keratometry measurements (Sw < 0.21 D) and was poor for corneal eccentricity (Sw 0.07; ICC 0.908; CV 14.58%). Agreement between WAM700 and Pentacam showed a high ICC for the keratometry measurements, central corneal thickness and anterior chamber depth (>0.972) but lower for corneal eccentricity (ICC 0.762). CONCLUSIONS In healthy eyes, the WAM700 multidiagnostic device showed good intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth measurements. Agreement between WAM700 and Pentacam was good for the anterior chamber depth measurement. However, these instruments cannot be considered interchangeable for keratometry, central corneal thickness and eccentricity readings.
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Affiliation(s)
- Ana Rosa Barrio
- Applied Vision Research Group, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | - Beatriz Antona
- Applied Vision Research Group, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
| | | | | | - Mariano González-Pérez
- Clinical and Experimental Eye Research Group, Faculty of Optics and Optometry, Complutense University of Madrid, Madrid, Spain
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Sáez-Gutiérrez FL, Velázquez JS, Alió del Barrio JL, Alio JL, Cavas F. Novel Multivariable Evolutionary Algorithm-Based Method for Modal Reconstruction of the Corneal Surface from Sparse and Incomplete Point Clouds. Bioengineering (Basel) 2023; 10:989. [PMID: 37627874 PMCID: PMC10451391 DOI: 10.3390/bioengineering10080989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 08/27/2023] Open
Abstract
Three-dimensional reconstruction of the corneal surface provides a powerful tool for managing corneal diseases. This study proposes a novel method for reconstructing the corneal surface from elevation point clouds, using modal schemes capable of reproducing corneal shapes using surface polynomial functions. The multivariable polynomial fitting was performed using a non-dominated sorting multivariable genetic algorithm (NS-MVGA). Standard reconstruction methods using least-squares discrete fitting (LSQ) and sequential quadratic programming (SQP) were compared with the evolutionary algorithm-based approach. The study included 270 corneal surfaces of 135 eyes of 102 patients (ages 11-63) sorted in two groups: control (66 eyes of 33 patients) and keratoconus (KC) (69 eyes of 69 patients). Tomographic information (Sirius, Costruzione Strumenti Oftalmici, Italy) was processed using Matlab. The goodness of fit for each method was evaluated using mean squared error (MSE), measured at the same nodes where the elevation data were collected. Polynomial fitting based on NS-MVGA improves MSE values by 86% compared to LSQ-based methods in healthy patients. Moreover, this new method improves aberrated surface reconstruction by an average value of 56% if compared with LSQ-based methods in keratoconus patients. Finally, significant improvements were also found in morpho-geometric parameters, such as asphericity and corneal curvature radii.
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Affiliation(s)
- Francisco L. Sáez-Gutiérrez
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain; (F.L.S.-G.); (J.S.V.)
| | - Jose S. Velázquez
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain; (F.L.S.-G.); (J.S.V.)
| | - Jorge L. Alió del Barrio
- Division of Ophthalmology, Miguel Hernández University, 03690 Alicante, Spain; (J.L.A.d.B.); (J.L.A.)
- Keratoconus Unit of Vissum Corporation Alicante, 03690 Alicante, Spain
- Department of Refractive Surgery, Vissum Corporation Alicante, 03690 Alicante, Spain
| | - Jorge L. Alio
- Division of Ophthalmology, Miguel Hernández University, 03690 Alicante, Spain; (J.L.A.d.B.); (J.L.A.)
- Keratoconus Unit of Vissum Corporation Alicante, 03690 Alicante, Spain
- Department of Refractive Surgery, Vissum Corporation Alicante, 03690 Alicante, Spain
| | - Francisco Cavas
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain; (F.L.S.-G.); (J.S.V.)
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Gonzalez-Salinas R, Franco JJ, Reyes-Luis JL, Sánchez-Huerta V, de Wit-Carter G, Hernández-Quintela E, Pineda R. Cataract surgery in patients with underlying keratoconus: focused review. J Cataract Refract Surg 2023; 49:97-102. [PMID: 36194107 DOI: 10.1097/j.jcrs.0000000000001069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 09/24/2022] [Indexed: 11/07/2022]
Abstract
An underlying diagnosis of keratoconus (KC) can complicate cataract surgery. In this study, the results of a focused review of the literature pertaining to cataract surgery in patients with KC are detailed. Topics essential for the appropriate management of this patient population are discussed. First, the individual and shared epidemiology and pathophysiology of cataract and KC are reviewed. Then, the theory and approach to intraocular lens power calculation are discussed, highlighting particularities and pitfalls of this exercise when performed in patients with KC. Finally, several special-although not uncommon-management scenarios and questions are addressed, such as surgical planning in cases where corneal stabilization or tissue replacement interventions are also necessitated.
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Affiliation(s)
- Roberto Gonzalez-Salinas
- From the Anterior Segment Surgery Department, Asociación para Evitar la Ceguera I.A.P., Mexico City, Mexico (Gonzalez-Salinas); Harvard Medical School, Boston, Massachusetts (Franco, Pineda); Cornea and Refractive Surgery Service, Massachusetts Eye and Ear, Boston, Massachusetts (Reyes-Luis, Pineda); Cornea Department, Asociación para Evitar la Ceguera I.A.P., Mexico City, Mexico (Sánchez-Huerta, de Wit-Carter); Division of Comprehensive Ophthalmology, Wilmer Eye Institute, Johns Hopkins Medicine, Baltimore, Maryland (Hernández-Quintela)
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Kose B. Agreement between swept-source optical biometry and Scheimpflug-based topography measurements of posterior corneal curvature. J Cataract Refract Surg 2022; 48:185-189. [PMID: 34174042 DOI: 10.1097/j.jcrs.0000000000000731] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 06/14/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate agreement of posterior corneal curvature parameters between a swept-source optical coherence tomography-based biometer (IOLMaster 700) and Scheimpflug topography (Pentacam HR) in healthy, myopic eyes. SETTING Department of Ophthalmology, Osmangazi Aritmi Hospital, Bursa, Turkey. DESIGN Retrospective study. METHODS In this study, 59 eyes of 59 patients who applied as candidates for refractive surgery were included. Measurements of the posterior corneal curvature were performed using IOLMaster 700 and Pentacam HR. J0 and J45 vector components were calculated using astigmatic values. Posterior corneal keratometry (K) measurements at flat (K flat) and steep (K steep) axes and J0 and J45 values were compared between the 2 devices. The agreement between the devices was analyzed using the Bland-Altman method. Intraclass correlation coefficients and within-subject SD were calculated to assess the repeatability. RESULTS 59 eyes of 59 patients were included in this study. The IOLMaster 700 provided significantly flatter K flat and K steep values (P < .001, for both). Significant differences were found in J0 and J45 values (P = 0.13 and P < .001, respectively). The mean differences between K flat, K steep, and J0 and J45 values were 0.49 diopter (D), 0.53 D, 0.04 D, and -0.05 D, respectively. CONCLUSIONS The IOLMaster 700 and the Pentacam HR could not be used interchangeably to measure K flat, K steep, and J0 and J45 values of the posterior corneal curvature in healthy, myopic eyes. Both devices showed high repeatability for posterior corneal curvature measurement.
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Affiliation(s)
- Bulent Kose
- From the Department of Ophthalmology, Osmangazi Aritmi Hospital, Bursa, Turkey
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Oleszko AA, Marek JJ, Muzyka‐woźniak MM. Horizontal and anterior chamber diameter for phakic intraocular lens sizing. Clin Exp Optom 2021; 104:62-68. [DOI: 10.1111/cxo.13101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Alvarez ER, Montesinos GM, Torres Piedra DM, Palacios NT, Téllez OF. Corneal Indices Determined with Pentacam in Possible Candidates for Corneal Refractive Surgery. Open Ophthalmol J 2020. [DOI: 10.2174/1874364102014010039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Objective:
To describe the level of correlation of clinical refractive variables with corneal indices in Pentacam Scheimpflug tomography, demonstrate the usefulness of the study of corneal indices in the diagnosis of keratoconus (KC), and identify the corneal indexes with the greatest influence on the diagnosis of KC.
Methods:
A descriptive, retrospective, and cross-sectional study was conducted in 69 patients (138 eyes) with refractive disorders, possible candidates for corneal refractive surgery, at the Exilaser Ophthalmological Center, Cuenca, Ecuador, from March to August 2019. Corneal indices were studied using Pentacam. Statistical correlation methods, Levene’s test, Fisher’s exact test, Cramérs’ V coefficient, and multiple correspondence analyses were used.
Results:
The variables refractive cylinder and central keratometry had a direct correlation with the corneal indices (p<0.001). An inverse correlation was obtained between central pachymetry and corneal indices (p<0.001). A high level of dependence on central KC index (CKI) (Cramér V = 0.785) and KC index (KI) (Cramér V = 0.775) was obtained with the diagnosis of KC.
Conclusion:
Pentacam is a valuable tool in the analysis of corneal indices for the diagnosis of KC, given its high level of correlation with clinical refractive variables. The selection of candidates for refractive surgery, even when there is no diagnosis of KC, is strengthened with the analysis of the corneal indices. The indices with the most intense level of dependence with the diagnosis of KC are, in order, the following indices: CKI, KI, vertical asymmetry, minimum radius, and variation of the surface.
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Biometric Measurement of Anterior Segment: A Review. SENSORS 2020; 20:s20154285. [PMID: 32752014 PMCID: PMC7435894 DOI: 10.3390/s20154285] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/22/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022]
Abstract
Biometric measurement of the anterior segment is of great importance for the ophthalmology, human eye modeling, contact lens fitting, intraocular lens design, etc. This paper serves as a comprehensive review on the historical development and basic principles of the technologies for measuring the geometric profiles of the anterior segment. Both the advantages and drawbacks of the current technologies are illustrated. For in vivo measurement of the anterior segment, there are two main challenges that need to be addressed to achieve high speed, fine resolution, and large range imaging. One is the motion artefacts caused by the inevitable and random human eye movement. The other is the serious multiple scattering effects in intraocular turbid media. The future research perspectives are also outlined in this paper.
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Velázquez JS, Cavas F, Piñero DP, Cañavate FJ, Alio del Barrio J, Alio JL. Morphogeometric analysis for characterization of keratoconus considering the spatial localization and projection of apex and minimum corneal thickness point. J Adv Res 2020; 24:261-271. [PMID: 32382446 PMCID: PMC7200195 DOI: 10.1016/j.jare.2020.03.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 02/07/2023] Open
Abstract
This work evaluates changes in new morphogeometric indices developed considering the position of anterior and posterior corneal apex and minimum corneal thickness (MCT) point in keratoconus. This prospective comparative study included 440 eyes of 440 patients (age, 7-99 years): control (124 eyes) and keratoconus (KC) groups (316 eyes). Tomographic information (Sirius®, Costruzione Strumenti Oftalmici, Italy) was treated with SolidWorks v2013, creating the following morphogeometric parameters: geometric axis-apex line angle (GA-AP), geometric axis-MCT line angle (GA-MCT, apex line-MCT line angle (AP-MCT), and distances between apex and MCT points on the anterior (anterior AP-MCTd) and posterior corneal surface (posterior AP-MCTd). Statistically significant higher values of GA-AP, GA-MCT, AP-MCT and anterior AP-MCTd were found in the keratoconus group (p ≤ 0.001). Moderate significant correlations of corneal aberrations (r ≥ 0.587, p < 0.001) and corneal thickness parameters (r ≤ -0.414, p < 0.001) with GA-AP and AP-MCT were found. Anterior asphericity was found to be significantly correlated with anterior and posterior AP-MCTd (r ≥ 0.430, p < 0.001). Likewise, GA-AP and AP-MCT showed a good diagnostic ability for the detection of keratoconus, with optimal cutoff values of 9.61° (sensitivity 85.5%, specificity 80.3%) and 18.08° (sensitivity 80.5%, specificity 78.7%), respectively. These new morphogeometric indices allow a clinical characterization of the 3-D structural alteration occurring in keratoconus, with less coincidence in the spatial projection of the apex and MCT points of both corneal surfaces. Future studies should confirm the potential impact on the precision of these indices of the variability of posterior corneal surface measurements obtained with Scheimpflug imaging technology.
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Affiliation(s)
- Jose S. Velázquez
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain
| | - Francisco Cavas
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain
| | - David P. Piñero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain
| | - Francisco J.F. Cañavate
- Department of Structures, Construction and Graphical Expression, Technical University of Cartagena, 30202 Cartagena, Spain
| | - Jorge Alio del Barrio
- Division of Ophthalmology, Miguel Hernández University, 03690 Alicante, Spain
- Keratoconus Unit of Vissum Corporation Alicante, 03690 Alicante, Spain
- Department of Refractive Surgery, Vissum Corporation Alicante, 03690 Alicante, Spain
| | - Jorge L. Alio
- Division of Ophthalmology, Miguel Hernández University, 03690 Alicante, Spain
- Keratoconus Unit of Vissum Corporation Alicante, 03690 Alicante, Spain
- Department of Refractive Surgery, Vissum Corporation Alicante, 03690 Alicante, Spain
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Yu Z, Li J, Song H. Short-time evaluation on intraocular scattering after implantable collamer lens implantation for correcting high myopia. BMC Ophthalmol 2020; 20:235. [PMID: 32552888 PMCID: PMC7301533 DOI: 10.1186/s12886-020-01482-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/25/2020] [Indexed: 01/19/2023] Open
Abstract
Background To compare the intraocular scattering before and after implantation of implantable collamer lens (ICL) V4c for correction of high myopia in a short term. Methods In this study, 38 eyes of 19 patients who underwent the implantation of ICL V4c were followed up for 3 months. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), objective scattering index (OSI), modulation transfer function cutoff frequency (MTF cutoff), strehl ratio (S/R), OV100%, OV20% and OV9% were measured pre- and postoperatively. Meantime, the Pseudophakic Dysphotopsia Questionnaire (PDQ) was scored to evaluate the subjective satisfaction of intraocular scattering pre- and postoperatively. Results The UCVA were − 0.02 ± 0.06, − 0.03 ± 0.07 and − 0.04 ± 0.07 logMAR at 1 week, 1 month and 3 months postoperatively which were significantly better than those preoperatively (P < 0.05). The BCVA were − 0.09 ± 0.09, − 0.09 ± 0.1 and − 0.1 ± 0.11 logMAR at 1 week, 1 month and 3 months after surgery, which were better than those before surgery significantly (t = 15.64, P < 0.05). The mean OSI were 2.37 ± 1.6, 1.63 ± 0.94, 1.5 ± 0.86 and 1.43 ± 1.05 preoperatively, 1 week, 1 month and 3 months postoperatively which was found significant difference (F = 12.92 P < 0.05). No significant differences were found in MTF cut off (F = 0.61, P = 0.62), S/R (F = 0.58, P = 0.36), OV100% (F = 0.966, P = 0.65), OV20% (F = 0.121, P = 0.96) and OV9% (F = 1.01, P = 0.30) between pre- and postoperatively. The PDQ results indicated that intraocular scattering reduced at 3 months after surgery significantly (P < 0.05). Conclusions The ICL V4c implantation for correcting high myopia induced less intraocular scattering and visual disorder than spectacle correction.
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Affiliation(s)
- Zhe Yu
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Nankai University Eye Hospital, No. 4 Gansu Road, Heping District, Tianjin, People's Republic of China
| | - Jun Li
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Nankai University Eye Hospital, No. 4 Gansu Road, Heping District, Tianjin, People's Republic of China.
| | - Hui Song
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology, Tianjin Medical University, Nankai University Eye Hospital, No. 4 Gansu Road, Heping District, Tianjin, People's Republic of China.
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Vega-Estrada A, Fariselli C, Alio JL. Posterior corneal features in patients with Down syndrome and their relation with keratoconus. Br J Ophthalmol 2020; 104:1683-1689. [PMID: 32122914 DOI: 10.1136/bjophthalmol-2019-314939] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/13/2019] [Accepted: 02/13/2020] [Indexed: 11/03/2022]
Abstract
AIMS To characterise posterior corneal surface features in patients with Down syndrome (DS) and to compare them with healthy and mild keratoconus corneas. METHODS This restrospective, comparative, non-randomised, clinical study included 123 eyes, divided into three groups (37 eyes of patients with DS, 46 with mild keratoconus and 40 controls), and took place at Vissum Alicante. Only patients with no previous ocular surgery, no corneal scars and no active ocular disease other than keratoconus were included. The Sirius System topographer (CSO, Firenze, Italy) was used in order to analyse posterior corneal surface keratometry, shape and keratoconus screening indices, posterior corneal aberrations, corneal volume and pachymetry. RESULTS Patients with DS, when compared with healthy controls, have a steeper (mean keratometry 7 mm (KM): -6.30±0.44 vs -6.15±0.22; p<0.05) and more irregular (root mean square per unit of area: 4.5 mm 0.22±0.22 vs 0.09±0.03, p<0.001; posterior vertex of the ectatic area: 33.22±44.29 vs 10.63±2.88, p<0.001) posterior corneal surface, with higher aberrations (high-order aberrations (HOAs): 1.07±1.43 vs 0.15±0.06, p<0.001; coma-like: 0.88±1.09 vs 0.13±0.07, p<0.001) and thinnest pachymetry (497.68±26.88 vs 538.95±31.67, p<0.001). At the same time, no statistically significant difference was found between patients with DS and patients with mild keratoconus (p>0.05) in KM (-6.38±0.34), HOA (0.56±0.36), coma-like (0.51±0.34) and pachymetry (500.56±36.83). CONCLUSIONS Posterior corneal surface of patients with DS is steeper, more irregular and shows more higher order aberrations, as well as reduced volume and thinner pachymetry than patients with healthy corneas. Additionally, posterior corneal surface in patients with DS shows similar characteristics to those found in mild keratoconus.
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Affiliation(s)
- Alfredo Vega-Estrada
- Cornea and Refractive Surgery Department, Vissum, Alicante, Spain
- Research and Development Department, Vissum, Alicante, Spain
- Vissum Corporation, Alicante, Spain
| | | | - Jorge L Alio
- Cornea and Refractive Surgery Department, Vissum, Alicante, Spain
- Research and Development Department, Vissum, Alicante, Spain
- Vissum Corporation, Alicante, Spain
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Alio JL, Vega-Estrada A, Sanz P, Osman AA, Kamal AM, Mamoon A, Soliman H. Corneal Morphologic Characteristics in Patients With Down Syndrome. JAMA Ophthalmol 2019; 136:971-978. [PMID: 29931124 DOI: 10.1001/jamaophthalmol.2018.2373] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Importance Literature suggests corneal morphologic characteristics compatible with keratoconus are present in a high percentage of patients with Down syndrome (DS), suggesting the need to perform a detailed examination of the anterior segment to try to avoid serious visual impairment in this group of patients. Objective To characterize the abnormal features of the cornea in patients with DS and compare these with a control group. Design, Setting, and Participants Multicenter case-control study at Vissum Alicante, Alicante, Spain, and the Ophthalmology and Pediatric Department, Cairo University, Cairo, Egypt. Data collection took place between May 2013 and May 2016. Data were analyzed between June 2016 and August 2016. The study included 321 eyes of 217 participants from 2 groups: 112 participants in the DS group and 105 healthy participants in the control group. Interventions Patients were evaluated using Placido disc/Scheimpflug camera topographer (Sirius, CSO). Visual, refractive and anterior, and posterior corneal characteristics were assessed and compared in both groups. Main Outcomes and Measures Keratoconus diagnosis. Incidence of corneal morphologic irregularities similar to keratoconus in patients with DS. Results In the DS group, mean (SD) age was 14.88 (15.76) years, 54 (48%) were women, 66 (59%) were white, and 46 (41%) were Arab. In the control group, mean (SD) age was 40.29 (14.66) years, 54 (51%) were women, and all were white. Clinical assessment of corneal topography showed that 71.3% (95% CI, 45.2-97.4) of patients in the DS group showed characteristics compatible with keratoconus. Differences were found in steepest keratometry of 47.35 diopters (D) in patients with DS vs 43.70 D in control individuals (difference, 3.65 D; 95% CI, 3.23-4.35 D; P <.001) and in corneal pachymetry of 503 μm in patients with DS vs 545 μm in control individuals (difference, 42 μm; 95% CI, 38.8-56.7 μm; P <.001). Conclusions and Relevance Patients with DS have steeper and thinner corneas and more corneal aberrations than those without genetic alterations and normal corneas. The findings suggest a detailed corneal study should be considered in such patients to detect keratoconus and implement treatment as appropriate to try to avoid serious visual impairment in this group of patients.
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Affiliation(s)
- Jorge L Alio
- Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain.,Keratoconus Unit of Vissum Corporation Alicante, Alicante, Spain.,Department of Refractive Surgery, Vissum Corporation Alicante, Alicante, Spain
| | - Alfredo Vega-Estrada
- Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain.,Keratoconus Unit of Vissum Corporation Alicante, Alicante, Spain.,Department of Refractive Surgery, Vissum Corporation Alicante, Alicante, Spain
| | - Pablo Sanz
- Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
| | - Amr A Osman
- Department of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Ahmed M Kamal
- Department of Ophthalmology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Amr Mamoon
- Genetics Unit, Cairo University Children's Hospital, Cairo, Egypt
| | - Hany Soliman
- Genetics Unit, Cairo University Children's Hospital, Cairo, Egypt
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Piñero DP, Molina-Martín A, Camps VJ, de Fez D, Caballero MT. Validation of corneal topographic and aberrometric measurements obtained by color light-emitting diode reflection topography in healthy eyes. Graefes Arch Clin Exp Ophthalmol 2019; 257:2437-2447. [PMID: 31482276 DOI: 10.1007/s00417-019-04453-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/12/2019] [Accepted: 08/27/2019] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To evaluate the intrasession repeatability of anterior corneal topographic and aberrometric measurements provided by a color-LED topographer as well as their interchangeability with those provided by a Scheimpflug-based system in healthy eyes. METHODS Thirty-five healthy eyes of 35 patients (age, 16-66 years) were enrolled. A complete eye examination was performed in all cases including a complete corneal analysis with the Scheimpflug-based system Pentacam (Oculus Optikgeräte) (one measurement) and the Cassini system (i-Optics) (three consecutive measurements). Intrasession repeatability of the Cassini measurements was assessed with the within-subject standard deviation (Sw) and the intraclass correlation coefficient (ICC). The Bland-Altman analysis was used to evaluate the agreement between both devices. RESULTS Mean Sw for keratometric readings was 0.02 mm (ICC ≥ 0.992), ranging between 0.16 and 0.05 D (ICC 0.930-0.978) for anterior and total astigmatic measurements. Mean Sw for asphericity and corneal diameter were 0.06 (ICC 0.926) and 0.03 mm (IC 0.997), respectively. Aberrometric parameters showed ICCs ≥ 0.816, except for Z42 (ICC 0.741) and Z44 (ICC 0.544). When comparing devices, statistically significant differences were found for most of topographic and aberrometric data (p ≤ 0.044). Likewise, ranges of agreement between devices were clinically relevant (keratometry > 0.06 mm; total astigmatic components > 0.69 D; asphericity 0.35; second-, third-, and fourth-order Zernike terms, more than 0.20, 0.13, and 0.01 μm, respectively). CONCLUSIONS Consistent anterior corneal topographic, total corneal astigmatic, and aberrometric measurements are obtained with color-LED topography in healthy eyes, which are not interchangeable with those provided by the Scheimpflug-based topography.
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Affiliation(s)
- David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain.
- Department of Ophthalmology, Vithas Medimar International Hospital, Alicante, Spain.
| | - Ainhoa Molina-Martín
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
| | - Vicent J Camps
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
| | - Dolores de Fez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
| | - María Teresa Caballero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
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14
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Piñero DP, Camps VJ, de Fez D, García C, Caballero MT. Validation of posterior corneal curvature measurements with color light-emitting diode topography. Eur J Ophthalmol 2019; 30:1261-1267. [PMID: 31432704 DOI: 10.1177/1120672119870738] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To evaluate the intrasession repeatability and validity of posterior corneal curvature and astigmatism measurements provided by a color light-emitting diode reflection topography system in healthy eyes. METHODS A total of 40 healthy eyes of 40 patients (age, 16-66 years) were enrolled. A complete eye examination was performed in all cases including posterior topographic analysis with two systems: the Scheimpflug-based system (Pentacam; Oculus Optikgeräte GmbH, Wetzlar, Germany) and the Cassini system (i-Optics; Ophthec, The Hague, The Netherlands). With this last system, three consecutive measurements were taken to assess the level of intrasession repeatability (within-subject standard deviation, Sw; intraclass correlation coefficient). The Bland & Altman analysis was used to evaluate the interchangeability of both devices. RESULTS The Sw was ⩽0.06 mm for all posterior corneal radius measurements, with intraclass correlation coefficient of ⩾0.960. The Sw for the magnitude of astigmatism, J0, and J45 were 0.15, 0.04, and 0.04 D, respectively, with intraclass correlation coefficient values of 0.876, 0.897, and 0.840, respectively. Statistically significant differences between devices were found in all parameters evaluated (p ⩽ 0.025). The interchangeability analysis revealed the presence of clinically relevant limits of agreement for the flattest (0.03 to 0.50 mm) and steepest posterior corneal radii (-0.01 to 0.39 mm). In contrast, limits of agreements were not clinically relevant for the magnitude of posterior astigmatism (-0.17 to 0.27 D) and their power vector components (-0.11 to 0.15 D). CONCLUSION The Cassini system provides consistent measures of posterior corneal curvature and astigmatism in healthy eyes, but only measures of posterior astigmatism can be considered as interchangeable with those provided by the Pentacam.
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Affiliation(s)
- David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain.,Department of Ophthalmology, Vithas Medimar International Hospital, Alicante, Spain
| | - Vicent J Camps
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Dolores de Fez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Celia García
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
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Clinical Outcomes of a New Asymmetric Intracorneal Ring Segment for the Treatment of Keratoconus. Cornea 2019; 38:1228-1232. [DOI: 10.1097/ico.0000000000002062] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Analysis of Intrasession Repeatability of Ocular Aberrometric Measurements and Validation of Keratometry Provided by a New Integrated System in Mild to Moderate Keratoconus. Cornea 2019; 38:1097-1104. [DOI: 10.1097/ico.0000000000002034] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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17
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Piñero DP, Soto-Negro R, Ruiz-Fortes P, Pérez-Cambrodí RJ, Fukumitsu H. Interchangeability of corneal curvature and asphericity measurements provided by three different devices. Int J Ophthalmol 2019; 12:412-416. [PMID: 30918809 DOI: 10.18240/ijo.2019.03.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/17/2018] [Indexed: 12/22/2022] Open
Abstract
AIM To evaluate the interchangeability of keratometric and asphericity measurements provided by three measurement systems based on different optical principles. METHODS A total of 40 eyes of 40 patients with a mean age of 34.1y were included. In all cases, a corneal curvature analysis was performed with IOL-Master (IOLM), iDesign 2 (ID2), and Sirius systems (SIR). Differences between instruments for flattest (K1) and steepest (K2) keratometric readings, as well as for magnitude and axis of corneal astigmatism were analyzed. Likewise, differences in asphericity (Q) between SIR and ID2 were also evaluated. RESULTS Mean differences between devices for K1 were 0.20±0.21 (P<0.001), -0.12±0.36 (P=0.046) and -0.32±0.36 D (P<0.001) for the comparisons IOLM-SIR, IOLM-ID2 and SIR-ID2, respectively. The ranges of agreement for these comparisons between instruments were 0.41, 0.70, and 0.70 D. For K2, mean differences were 0.31±0.33 (P<0.001), -0.08±0.43 (P=0.265) and -0.39±0.38 D (P<0.001), with ranges of agreement of 0.65, 0.84, and 0.74 D. Concerning magnitude of astigmatism, ranges of agreement were in the limit of clinical relevance (0.49 D, P=0.011; 0.55 D, P=0.386; 0.43 D, P=0.05). In contrast, ranges of agreement were clinically relevant for astigmatic axis (26.68°, 33.83° and 18.37°, P≥0.121) and for Q between SIR and ID2 (0.16, P<0.001). CONCLUSION The keratometric corneal power, astigmatic axis and asphericity measurements provide by the three systems evaluated cannot be considered as interchangeable, whereas measurements of corneal astigmatism obtained with SIR and ID2 can be considered as interchangeable for clinical purposes.
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Affiliation(s)
- David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, San Vicente del Raspeig 03690, Alicante, Spain.,Department of Ophthalmology (OFTALMAR), Vithas Medimar International Hospital, Alicante 03014, Spain
| | - Roberto Soto-Negro
- Department of Ophthalmology (OFTALMAR), Vithas Medimar International Hospital, Alicante 03014, Spain
| | - Pedro Ruiz-Fortes
- Department of Ophthalmology (OFTALMAR), Vithas Medimar International Hospital, Alicante 03014, Spain
| | - Rafael J Pérez-Cambrodí
- Department of Ophthalmology (OFTALMAR), Vithas Medimar International Hospital, Alicante 03014, Spain
| | - Hideki Fukumitsu
- Department of Ophthalmology (OFTALMAR), Vithas Medimar International Hospital, Alicante 03014, Spain.,Department of Ophthalmology, Marina Baixa Hospital, Villajoyosa 03570, Alicante, Spain
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18
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Assessment of Pattern and Shape Symmetry of Bilateral Normal Corneas by Scheimpflug Technology. Symmetry (Basel) 2018. [DOI: 10.3390/sym10100453] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose: The aim of this study was to assess bilateral symmetry in normal fellow eyes by using optical and geometric morphometric parameters. Methods: All participants underwent complete biocular examinations. Scheimpflug tomography data from 66 eyes of 33 patients were registered. The interocular symmetry was based on five patterns: morphogeometric symmetry, axial symmetry at the corneal vertex, angular-spatial symmetry, direct symmetry (equal octants), and enantiomorphism (mirror octants). Results: No statistically significant differences were found between right and left eyes in corneal morphogeometric (p ≥ 0.488) and aberrometric parameters (p ≥ 0.102). Likewise, no statistically significant differences were found in any of the axial symmetry parameters analyzed (p ≥ 0.229), except in the surface rotation angle beta (p = 0.102) and translation coordinates X0 and Y0 (p < 0.001) for the anterior corneal surface, and the rotation angle gamma (p < 0.001) for the posterior surface. Similarly, no statistically significant differences were identified for direct symmetry (p ≥ 0.20) and enantiomorphism (p ≥ 0.75), except for some elevation data in the posterior surface (p < 0.01). Conclusions: The level of symmetry of both corneas of a healthy individual is high, with only some level of disparity between fellow corneas in rotation and translation references. Abnormalities in this pattern of interocular asymmetry may be useful as a diagnostic tool.
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Gordon-Shaag A, Piñero DP, Kahloun C, Markov D, Parnes T, Gantz L, Shneor E. Validation of refraction and anterior segment parameters by a new multi-diagnostic platform (VX120). JOURNAL OF OPTOMETRY 2018; 11:242-251. [PMID: 29526690 PMCID: PMC6147758 DOI: 10.1016/j.optom.2017.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 12/17/2017] [Accepted: 12/27/2017] [Indexed: 05/30/2023]
Abstract
BACKGROUND The VX120 (Visionix Luneau, France) is a novel multi-diagnostic platform that combines Hartmann-Shack based autorefraction, Placido-disk based corneal-topography and anterior segment measurements made with a stationary-Scheimpflug camera. We investigate the agreement between different parameters measured by the VX120 with accepted or gold-standard techniques to test if they are interchangeable, as well as to evaluate the repeatability and reproducibility. METHODS The right-eyes of healthy subjects were included in the study. Autorefraction of the VX120 was compared to subjective refraction. Agreement of anterior segment parameters was compared to the Sirius (CSO, Italy) including autokeratometry, central corneal thickness (CCT), iridiocorneal angle (IA). Inter and intra-test repeatability of the above parameters was assessed. Results were analyzed using Bland and Altman analyses. RESULTS A total of 164 eyes were evaluated. The mean difference between VX120 autorefraction and subjective refraction for sphere, spherical equivalent (SE), and cylinder was 0.01±0.43D, 0.14±0.47D, and -0.26±0.30D, respectively and high correlation was found to all parameter (r>0.75) except for J45 (r=0.61). The mean difference between VX120 and the Sirius system for CCT, IA, and keratometry (k1 and k2) was -3.51±8.64μm, 7.6±4.2°, 0.003±0.06mm and 0.004±0.04mm, respectively and high correlation was found to all parameter (r>0.97) except for IA (r=0.67). Intrasession repeatability of VX120 refraction, CCT, IA and keratometry yielded low within-subject standard deviations. Inter-session repeatability showed no statistically significant difference for most of the parameters measured. CONCLUSIONS The VX120 provides consistent refraction and most anterior segment measurements in normal healthy eyes, with high levels of intra and inter-session repeatability.
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Affiliation(s)
- Ariela Gordon-Shaag
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel
| | - David P Piñero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Spain
| | - Cyril Kahloun
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel
| | - David Markov
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel
| | - Tzadok Parnes
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel
| | - Liat Gantz
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel
| | - Einat Shneor
- Department of Optometry and Vision Science, Hadassah Academic College, Jerusalem, Israel.
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Bozkurt B, Yılmaz M, Meşen A, Kamış Ü, Ekinci Köktekir B, Okudan S. Correlation of Corneal Endothelial Cell Density with Corneal Tomographic Parameters in Eyes with Keratoconus. Turk J Ophthalmol 2017; 47:255-260. [PMID: 29109893 PMCID: PMC5661174 DOI: 10.4274/tjo.22800] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/24/2017] [Indexed: 12/01/2022] Open
Abstract
Objectives: To examine changes in corneal endothelial cell density (ECD) in different stages of keratoconus and evaluate its correlation with corneal tomographic parameters. Materials and Methods: Two hundred six patients with keratoconus were enrolled in the study. Corneal topography was performed by Sirius (CSO, Italy), which has a rotating Scheimpflug camera and a Placido disc topographer. Automatic endothelial analysis was done with the non-contact endothelial microscope (20x probe) of Confoscan-4 (NIDEK, Japan). The eyes were classified into stages based on steepest keratometric value as follows: mild <45 D; moderate 45-52 D; severe >52 D and according to thinnest cornea thickness (TCT) as <400 μm, 400-450 μm, and >450 μm. Tomographic and endothelial cell parameters were compared among the groups using Kruskal-Wallis test and the correlations between them were analyzed using Spearman correlation. Results: The study included 391 eyes of 100 male (24.29±7.7 years, range 11-47 years) and 106 female (26.26±7.5 years, range 13-45 years) patients (p=0.07). Mean ECD values were 2628±262 cells/mm2, 2541.9±260.4 cells/mm2, and 2414.6±384.3 cells/mm2 in mild, moderate, and severe keratoconus, respectively (p<0.001) and 2592.3±277 cells/mm2, 2502±307 cells/mm2 and 2348±296 cells/mm2 in corneas with TCT values >450 µm, 400-450 µm, and <400 µm, respectively (p<0.001). ECD showed significant negative correlation with keratometric and elevation parameters and positive correlation with pachymetric parameters (p<0.05). Conclusion: As endothelial cell numbers seem to decrease with the progression of keratoconus, specular/confocal microscopy screening should be carried out, especially in eyes with advanced stages and corneas with TCT <400 µm.
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Affiliation(s)
- Banu Bozkurt
- Selçuk University Faculty of Medicine, Department of Ophthalmology, Konya, Turkey
| | - Mevlüt Yılmaz
- Dr. Munif İslamoğlu State Hospital, Ophthalmology Clinic, Kastamonu, Turkey
| | - Ali Meşen
- Selçuk University Faculty of Medicine, Department of Ophthalmology, Konya, Turkey
| | - Ümit Kamış
- Dünyagöz Hospital, Ophthalmology Clinic, Konya, Turkey
| | | | - Süleyman Okudan
- Selçuk University Faculty of Medicine, Department of Ophthalmology, Konya, Turkey
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Piñero DP, Cabezos I, López-Navarro A, de Fez D, Caballero MT, Camps VJ. Intrasession repeatability of ocular anatomical measurements obtained with a multidiagnostic device in healthy eyes. BMC Ophthalmol 2017; 17:193. [PMID: 29047369 PMCID: PMC5648429 DOI: 10.1186/s12886-017-0589-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/16/2017] [Indexed: 11/10/2022] Open
Abstract
Background To evaluate the intrasession repeatability of anterior chamber depth (ACD), central (CCT) and peripheral corneal thickness (PCT), white-to-white diameter (WTW), and irido-corneal angle (IA) measurements obtained with a multidiagnostic device in healthy eyes. Methods A total of 107 eyes of 107 patients ranging in age from 23 to 65 years were examined with the VX120 system (Visionix-Luneau Technologies). Three consecutive measurements were obtained with this device to assess the intrasession repeatability of ACD, CCT, PCT at different nasal and temporal locations, WTW, and nasal and temporal IA. Data analysis included the calculation of within-subject standard deviation (Sw), intrasubject precision (1.96xSw), coefficient of variation (CV) and intraclass correlation coefficient (ICC). Results The Sw and CV for ACD was 0.03 mm and 1.16%, respectively, with an ICC of 0.992. The Sw values for central and peripheral pachymetric measurements were below 9 μm, with CV of less than 1.6% and ICC of 0.976 or higher. For IA measurements, Sw values of 0.84 or lower were found, with a CV between 1 and 2%, and an ICC of more than 0.970. The Sw for WTW was 0.24 mm and the CV was 1.95%. No statistically significant correlations were found between any anatomical parameter evaluated and their Sw and CV values associated (−0.220 ≤ r ≤ 0.204, p ≥ 0.125). Conclusions The VX120 system is able to provide repeatable measurements of anatomical parameters in healthy eyes. Inter-observer repeatability should be evaluated in future studies.
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Affiliation(s)
- David P Piñero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n 03016, San Vicente del Raspeig, Alicante, Spain.
| | - Inmaculada Cabezos
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n 03016, San Vicente del Raspeig, Alicante, Spain
| | | | - Dolores de Fez
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n 03016, San Vicente del Raspeig, Alicante, Spain
| | - María T Caballero
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n 03016, San Vicente del Raspeig, Alicante, Spain
| | - Vicente J Camps
- Group of Optics and Visual Perception, Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n 03016, San Vicente del Raspeig, Alicante, Spain
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22
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Shetty R, Agrawal A, Deshmukh R, Kaweri L, Rao HL, Nagaraja H, Jayadev C. Effect of post crosslinking haze on the repeatability of Scheimpflug-based and slit-scanning imaging devices. Indian J Ophthalmol 2017; 65:305-310. [PMID: 28513495 PMCID: PMC5452583 DOI: 10.4103/ijo.ijo_690_16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Purpose: The aim of this study was to analyze the effect of postcollagen crosslinking (CXL) haze on the measurement and repeatability of pachymetry and mean keratometry (Km) of four corneal topographers. Materials and Methods: Sixty eyes of sixty patients with progressive keratoconus who had undergone accelerated CXL (ACXL) underwent imaging with a scanning slit imaging device (Orbscan II) and three Scheimpflug imaging devices (Pentacam HR, Sirius, and Galilei). Post-ACXL haze was measured using the densitometry software on the Pentacam HR. Readings of the thinnest corneal thickness (TCT) and Km from three scans of each device were analyzed. Effect of haze on the repeatability of TCT and Km measurements was evaluated using regression models. Repeatability was assessed by coefficient of variation. Results: Corneal densitometry in different zones affected the repeatability of TCT measurement of Orbscan (P < 0.05) significantly but not the repeatability of TCT with Pentacam HR and Sirius (P = 0.03 and 0.05, respectively). Km values were affected by haze when measured with the Pentacam HR (P < 0.05). The repeatability of Km readings for all devices was unaffected by haze. In the anterior 0–2 mm and 2–6 mm zone, TCT (P = 0.43 and 0.45, respectively), Km values (P = 0.4 and 0.6, respectively), repeatability of TCT (P = 0.1 in both zones), and Km (P = 0.5 and 0.1, respectively) with Galilei were found to be the most reliable. Conclusion: Galilei measurements appear to be least affected by post-ACXL haze when compared with other devices. Hence, topography measurements in the presence of haze need to be interpreted with caution.
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Affiliation(s)
- Rohit Shetty
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | - Aarti Agrawal
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | - Rashmi Deshmukh
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | - Luci Kaweri
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | - Harsha L Rao
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | - Harsha Nagaraja
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
| | - Chaitra Jayadev
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bengaluru, Karnataka, India
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Polar Value Analysis of Low to Moderate Astigmatism with Wavefront-Guided Sub-Bowman Keratomileusis. J Ophthalmol 2017; 2017:5647615. [PMID: 28831306 PMCID: PMC5558636 DOI: 10.1155/2017/5647615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/09/2017] [Accepted: 03/28/2017] [Indexed: 11/25/2022] Open
Abstract
Purpose To evaluate the astigmatic outcomes of wavefront-guided sub-Bowman keratomileusis (WFG-SBK) for low to moderate myopic astigmatism. Methods This study enrolled 100 right eyes from 100 patients who underwent WFG-SBK for the correction of myopia and astigmatism. The polar value method was performed with anterior and posterior corneal astigmatism measured with Scheimpflug camera combined with Placido corneal topography (Sirius, CSO) and refractive astigmatism preoperatively and 1 month, 3 months, and 6 months postoperatively. Results Similar results for surgically induced astigmatism (SIA) and error of the procedure in both anterior corneal astigmatism (ACA) and total ocular astigmatism (TOA). There was a minor undercorrection of the cylinder in both ACA and TOA. Posterior corneal astigmatism (PCA) showed no significant change. Conclusions Wavefront-guided SBK could provide good astigmatic outcomes for the correction of low to moderate myopic astigmatism. The surgical effects were largely attributed to the astigmatic correction of the anterior corneal surface. Posterior corneal astigmatism remained unchanged even after WFG-SBK for myopic astigmatism. Polar value analysis can be used to guide adjustments to the treatment cylinder alongside a nomogram designed to optimize postoperative astigmatic outcomes in myopic WFG-SBK.
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Corneal Topographic and Aberrometric Measurements Obtained with a Multidiagnostic Device in Healthy Eyes: Intrasession Repeatability. J Ophthalmol 2017; 2017:2149145. [PMID: 28133542 PMCID: PMC5241482 DOI: 10.1155/2017/2149145] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/10/2016] [Accepted: 12/05/2016] [Indexed: 12/12/2022] Open
Abstract
Purpose. To evaluate the intrasession repeatability of corneal curvature, eccentricity, and aberrometric measurements obtained with a multidiagnostic device in healthy eyes. Methods. This study enrolled 107 eyes of 107 patients ranging in age from 23 to 65 years. All of them underwent a complete anterior segment examination with the VX120 system (Visionix-Luneau Technologies, Chartres, France). Three consecutive measurements were obtained. The within-subject standard deviation (Sw), intrasubject precision (1.96 × Sw), and intraclass correlation coefficient (ICC) were calculated. Results. All Sw for corneal power measurements were below 0.26 D, with ICC above 0.982. The Sw for corneal astigmatism at different areas (3, 5, and 7 mm) was below 0.21 D, with ICC above 0.913. Concerning the axis of astigmatism, its Sw was below 11.27°, with ICC above 0.975. The Sw and ICC for corneal eccentricity were 0.067 and 0.957, respectively. The Sw and ICC for high-order aberration root mean square (RMS) were 0.048 µm and 0.901, respectively. For 3rd- and 4th-order aberrometric parameters, all Sw were below 0.037 µm and all ICC were higher than 0.84, except for quadrafoil RMS (ICC: 0.689). Conclusions. The multidiagnostic device evaluated is able to provide consistent measurements of corneal power, eccentricity, and third- and fourth-order aberrations in healthy eyes.
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Caputo R, Versaci F, Pucci N, de Libero C, Danti G, De Masi S, Mencucci R, Novembre E, Jeng BH. Very Low Prevalence of Keratoconus in a Large Series of Vernal Keratoconjunctivitis Patients. Am J Ophthalmol 2016; 172:64-71. [PMID: 27640005 DOI: 10.1016/j.ajo.2016.09.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 09/07/2016] [Accepted: 09/07/2016] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the prevalence of keratoconus (KC) and other corneal abnormalities by means of videokeratography and tomography in a large series of patients affected by vernal keratoconjunctivitis (VKC). DESIGN Cross-sectional study. METHODS Setting: Single-center children's hospital. STUDY POPULATION A total of 651 consecutive patients with VKC and a control group of 500 were prospectively recruited between May 1, 2012 and September 30, 2013, with a minimum follow-up of 12 months. OBSERVATION PROCEDURE All patients were evaluated by means of a Scheimpflug camera combined with a Placido corneal topographer. Keratoconus, suspected keratoconus, or its absence were determined in each patient. The corneal symmetry index of front (SIf) and back curvature (SIb), shape indices, and thicknesses were compared between the 2 groups. MAIN OUTCOME MEASURES Prevalence of keratoconus and corneal indices modifications. RESULTS Five out of 651 patients (0.77%) demonstrated topographic signs of KC. Two of them were bilateral. All patients were older than 7 years of age, and the mean age was 11.54 years. Four other patients (0.61%) were classified as KC suspects by the screening program. Of 304 patients older than 11 years (mean age 14.4 years), 4 (1.32%) were found to have KCN, and 4 (1.32%) were KC suspects. The corneal indices of patients in the VKC group were extremely similar to those in the control group. (P > .05). CONCLUSIONS The prevalence of KC in our patient population, compared with previous reports in the literature, is much lower. The similar corneal indices in both groups suggest the absence of permanent corneal deformation due to VKC.
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Affiliation(s)
- Roberto Caputo
- Pediatric Ophthalmology Unit, A. Meyer Children's Hospital, Florence, Italy
| | | | - Neri Pucci
- Pediatric Allergology Unit, A. Meyer Children's Hospital, Florence, Italy
| | - Cinzia de Libero
- Pediatric Ophthalmology Unit, A. Meyer Children's Hospital, Florence, Italy
| | - Gioia Danti
- Pediatric Ophthalmology Unit, A. Meyer Children's Hospital, Florence, Italy
| | - Salvatore De Masi
- Statistics and Epidemiology Unit, A. Meyer Children's Hospital, Florence, Italy
| | - Rita Mencucci
- Ophthalmology Unit, Careggi Hospital, Florence, Italy
| | - Elio Novembre
- Pediatric Allergology Unit, A. Meyer Children's Hospital, Florence, Italy
| | - Bennie H Jeng
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland.
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Comparison of the Optical Quality between Small Incision Lenticule Extraction and Femtosecond Laser LASIK. J Ophthalmol 2016; 2016:2507973. [PMID: 27957338 PMCID: PMC5121460 DOI: 10.1155/2016/2507973] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/31/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose. To investigate the visual quality after SMILE and Femto-LASIK. Methods. About 123 eyes from 63 patients were enrolled in this study. The parameters were measured preoperatively and 1 week, 1 month, and 3 months postoperatively using Sirius System. Results. The MTF curve increase slightly from low to high frequency at 3 mm and 6 mm pupil diameter after SMILE surgery (P < 0.05) during the follow-up time comparing with the preoperative values. And the SR has a significant increase at various pupil diameters as well (P < 0.05). However, there was little increase for MTF at intermediate to high frequency at 3 mm pupil diameter after Femto-LASIK procedure (P < 0.05). And the SR had only significant increase at 3 mm pupil diameter. Between SMILE and Femto-LASIK, there was no statistic difference both in MTF and SR (P > 0.05) at 3 mm pupil diameter at vertical and horizontal meridian. However, significant difference was found in MTF at low to mediate frequency at 6 mm pupil diameter at vertical meridian at 1 week postoperatively (P < 0.05). Conclusions. Both SMILE and Femto-LASIK show a great improvement in optical quality at small diameter. It was found that SMILE shows better optical quality than Femto-LASIK at larger pupil diameter, which might be good for the night vision.
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Corneal topographic alterations after selective laser trabeculoplasty. Int Ophthalmol 2016; 37:905-910. [PMID: 27628588 DOI: 10.1007/s10792-016-0348-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/06/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE To investigate the presence of corneal alterations in the long term among patients with primary open-angle glaucoma (POAG) after a single session of selective laser trabeculoplasty (SLT) treatment. MATERIALS AND METHODS The files of the POAG patients who had been treated with SLT were evaluated retrospectively. The Pretreatment Scheimpflug corneal topographic (SCT) findings were then compared with the post-treatment findings. RESULTS The files of 33 patients were eligible. The changes in central corneal thickness, thinnest point of cornea, and posterior corneal asphericity at 5 and 8 mm were statistically significant (p = 0.03, 0.01, 0.02, and 0.04 respectively). On the other hand, the simulated K, anterior 3 mm K, anterior 5 mm K, posterior 3 mm K, posterior 5 mm K, anterior asphericity at 3 mm, posterior asphericity at 3 mm, and Zernike values did not change significantly following the treatment (p = 0.19, 0.08, 0.1, 0.3, 0.2, 0.75, 0.09, and 0.3 respectively). CONCLUSION SLT can slightly alter pretreatment SCT findings in 3-6 months. Clinicians should wait for at least 6 months after SLT before performing any subsequent surgeries that depend on corneal parameters.
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Garza-León M, de la Parra-Colín P, Barrientos-Gutierrez T. Estudio comparativo de la medición del poder corneal central usando el queratómetro manual, el IOLMaster® y el tomógrafo Sirius®. REVISTA MEXICANA DE OFTALMOLOGÍA 2016. [DOI: 10.1016/j.mexoft.2015.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Prakash G, Srivastava D. Single session, intrauser repeatability of anterior chamber biometric and corneal pachy-volumetric parameters using a new Scheimpflug+Placido device. JOURNAL OF OPTOMETRY 2016; 9:85-92. [PMID: 26338543 PMCID: PMC4812002 DOI: 10.1016/j.optom.2015.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/23/2015] [Indexed: 05/13/2023]
Abstract
PURPOSE To analyze single session, intrauser reliability of a Scheimpflug device for anterior chamber (AC) and corneal parameters. METHODS In this observational study, 100 normal candidates underwent Scheimpflug analysis with Sirius 3D Rotating Scheimpflug Camera and Topography System (Costruzione Strumenti Oftalmici, Italy). Two scans in dark room conditions were performed by the same experienced user. The candidates were asked to keep both eyes closed for 5min before the scans. Exclusion criteria were previous ocular surgery, corneal scarring and anterior segment/posterior segment anomalies. Only the right eyes were used for the analysis. Both corneal (central, minimum, and apical thickness, volume, horizontal visible iris diameter, and apical curvature) and anterior chamber (volume, depth, angle, horizontal diameter) measurements were evaluated. RESULTS There was no difference in the means of repeated measurements (p>0.05, ANOVA). Intraclass correlations between the measures were high and ranged from 0.995-0.997 for corneal to 0.964-0.997 for anterior chamber (AC) parameters. The precision of repeatability measures (1.96×Sw) was approximately 5μ for the central and minimum corneal thickness, 8μ for the apical corneal thickness, 0.06mm for AC (anterior chamber) depth and less than 2° for the AC angle. CONCLUSIONS Sirius Scheimpflug system has high repeatability for both corneal and AC parameters in normal eyes.
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Affiliation(s)
- Gaurav Prakash
- Department of Cornea and Refractive Surgery, NMC Eye Care, New Medical Center Specialty Hospital, Abu Dhabi, United Arab Emirates.
| | - Dhruv Srivastava
- Department of Cornea and Refractive Surgery, NMC Eye Care, New Medical Center Specialty Hospital, Abu Dhabi, United Arab Emirates
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Guber I, Bergin C, Perritaz S, Majo F. Correcting Interdevice Bias of Horizontal White-to-White and Sulcus-to-Sulcus Measures Used for Implantable Collamer Lens Sizing. Am J Ophthalmol 2016; 161:116-25.e1. [PMID: 26454242 DOI: 10.1016/j.ajo.2015.09.037] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/27/2015] [Accepted: 09/28/2015] [Indexed: 12/17/2022]
Abstract
PURPOSE To assess the agreement and repeatability of horizontal white-to-white (WTW) and horizontal sulcus-to-sulcus (STS) diameter measurements and use these data in combination with available literature to correct for interdevice bias in preoperative implantable collamer lens (ICL) size selection. DESIGN Interinstrument reliability and bias assessment study. METHODS A total of 107 eyes from 56 patients assessed for ICL implantation at our institution were included in the study. This was a consecutive series of all patients with suitable available data. The agreement and bias between WTW (measured with the Pentacam and BioGraph devices) and STS (measured with the HiScan device) were estimated. RESULTS The mean spherical equivalent was -8.93 ± 5.69 diopters. The BioGraph measures of WTW were wider than those taken with the Pentacam (bias = 0.26 mm, P < .01), and both horizontal WTW measures were wider than the horizontal STS measures (bias >0.91 mm, P < .01). The repeatability (Sr) of STS measured with the HiScan was 0.39 mm, which was significantly reduced (Sr = 0.15 mm) when the average of 2 measures was used. Agreement between the horizontal WTW measures and horizontal STS estimates when bias was accounted for was г = 0.54 with the Pentacam and г = 0.64 with the BioGraph. CONCLUSIONS Large interdevice bias was observed for WTW and STS measures. STS measures demonstrated poor repeatability, but the average of repeated measures significantly improved repeatability. In order to conform to the US Food and Drug Administration's accepted guidelines for ICL sizing, clinicians should be aware of and account for the inconsistencies between devices.
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Garza-León M, de la Parra-Colín P, Barrientos-Gutierrez T. Comparación de la medición del grosor corneal central medido con un nuevo equipo de tomografía con cámara de Scheimpflug y anillos de Plácido (Sirius®) y paquimetría ultrasónica en sujetos sanos. REVISTA MEXICANA DE OFTALMOLOGÍA 2015. [DOI: 10.1016/j.mexoft.2014.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Archer TJ, Reinstein DZ, Piñero DP, Gobbe M, Carp GI. Comparison of the predictability of refractive cylinder correction by laser in situ keratomileusis in eyes with low or high ocular residual astigmatism. J Cataract Refract Surg 2015; 41:1383-92. [DOI: 10.1016/j.jcrs.2014.10.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 09/30/2014] [Accepted: 10/11/2014] [Indexed: 11/16/2022]
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Wang Q, Ding X, Savini G, Chen H, Feng Y, Pan C, Hua Y, Huang J. Anterior chamber depth measurements using Scheimpflug imaging and optical coherence tomography: repeatability, reproducibility, and agreement. J Cataract Refract Surg 2014; 41:178-85. [PMID: 25465212 DOI: 10.1016/j.jcrs.2014.04.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 04/01/2014] [Accepted: 04/03/2014] [Indexed: 11/15/2022]
Abstract
PURPOSE To determine the repeatability, reproducibility, and agreement of anterior chamber depth (ACD) measurements obtained with 3 Scheimpflug cameras and an anterior segment optical coherence tomography (AS-OCT) device. SETTING Eye Hospital of Wenzhou Medical University, Zhejiang, China. DESIGN Observational cross-sectional study. METHODS Two observers took 3 consecutive measurements in healthy right eyes using each device to assess intraoperator repeatability. The mean values obtained at different sessions by the first operator were used to determine the intersession reproducibility. Three consecutive measurements obtained by the first operator at the first session were averaged and used to assess agreement. RESULTS The ACD measurements obtained by 2 observers in 71 eyes were highly repeatable using the 4 devices, with a test-retest repeatability of 0.04 to 0.07 mm for intraoperator repeatability. The interoperator and intersession reproducibility of ACD measurements were high, and the test-retest repeatability ranges of interoperator and intersession reproducibility were 0.06 to 0.07 mm and 0.05 to 0.08 mm, respectively. The ACD measurements of the 4 systems were sorted from the thickest to the thinnest (Galilei G2 > Visante > Sirius > Pentacam). The differences in the measurements were statistically significant except between the ACD measurements obtained by the Sirius device and the Visante device. However, good agreement with narrow 95% limits of agreement was found between these devices. CONCLUSIONS The 4 devices provided high intraoperator repeatability and interoperator and intersession reproducibility for ACD measurements. Good agreement in ACD measurements was found between the devices in healthy eyes. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Qinmei Wang
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy
| | - Xixia Ding
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy
| | - Giacomo Savini
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy
| | - Hao Chen
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy
| | - Yifan Feng
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy
| | - Chao Pan
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy
| | - Yanjun Hua
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy
| | - Jinhai Huang
- From the School of Optometry and Ophthalmology and Eye Hospital (Wang, Ding, Chen, Feng, Pan, Hua, Huang), Wenzhou Medical University, and the Key Laboratory of Vision Science (Wang, Ding, Chen, Huang), Ministry of Health P.R. China, Wenzhou, Zhejiang, China; G.B. Studio Oculistico d'Azeglio (Savini), Bologna, Italy.
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Comparison of central corneal thickness, thinnest corneal thickness, anterior chamber depth, and simulated keratometry using galilei, Pentacam, and Sirius devices. Cornea 2014; 33:582-6. [PMID: 24763122 DOI: 10.1097/ico.0000000000000119] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim was to evaluate the agreement in the central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior chamber depth (ACD), and mean simulated keratometry (simK) measurements using Pentacam, Galilei, and Sirius Scheimpflug systems in normal eyes. METHODS Anterior segment measurements were performed with Pentacam, Galilei, and Sirius devices in 32 healthy subjects. The right eye of each participant was selected. Measurements obtained with the 3 systems were compared using repeated-measures analysis of variance and Bonferroni multiple comparisons test. RESULTS Analysis of variance determined a significant difference in the anterior segment measurements of CCT, TCT, ACD, and simK between the 3 devices (P < 0.001). Pairwise comparisons of CCT and TCT measurements were significantly different except for the comparison between Pentacam and Sirius. All pairwise comparisons for ACD were statistically significant. The pairwise comparison results for simK values showed that the Galilei and Sirius systems demonstrated better agreement with each other than with Pentacam. CONCLUSIONS The results of this study suggest that the Pentacam, Galilei, and Sirius Scheimpflug systems should not be accepted as interchangeable for CCT, TCT, ACD, and simK in healthy subjects.
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Comparison of Anterior Segment Measurements with Scheimpflug/Placido Photography-Based Topography System and IOLMaster Partial Coherence Interferometry in Patients with Cataracts. J Ophthalmol 2014; 2014:540760. [PMID: 25400939 PMCID: PMC4226174 DOI: 10.1155/2014/540760] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/29/2014] [Accepted: 09/29/2014] [Indexed: 11/17/2022] Open
Abstract
Purpose. To assess the consistency of anterior segment measurements obtained using a Sirius Scheimpflug/Placido photography-based topography system (CSO, Italy) and IOLMaster partial coherence interferometry (Carl Zeiss Meditec, Germany) in eyes with cataracts. Methods. A total of 90 eyes of 90 patients were included in this prospective study. The anterior chamber depth (ACD), keratometry (K), corneal astigmatism axis, and white to white (WTW) values were randomly measured three times with Sirius and IOLMaster. Concordance between them was assessed by calculating 95% limits of agreement (LoA). Results. The ACD and K taken with the Sirius were statistically significantly higher than that taken with the IOLMaster; however, the Sirius significantly underestimated the WTW values compared with the IOLMaster. Good agreement was found for Km and ACD measurements, with 95% LoA of -0.20 to 0.54 mm and -0.16 to 0.34 mm, respectively. Poor agreement was observed for astigmatism axis and WTW measurements, as the 95% LoA was -23.96 to 23.36° and -1.15 to 0.37 mm, respectively. Conclusion. With the exception of astigmatism axis and WTW, anterior segment measurements taken by Sirius and IOLMaster devices showed good agreement and may be used interchangeably in patients with cataracts.
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Cavas-Martínez F, Fernández-Pacheco DG, De la Cruz-Sánchez E, Nieto Martínez J, Fernández Cañavate FJ, Vega-Estrada A, Plaza-Puche AB, Alió JL. Geometrical custom modeling of human cornea in vivo and its use for the diagnosis of corneal ectasia. PLoS One 2014; 9:e110249. [PMID: 25329896 PMCID: PMC4201525 DOI: 10.1371/journal.pone.0110249] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 09/14/2014] [Indexed: 11/18/2022] Open
Abstract
AIM To establish a new procedure for 3D geometric reconstruction of the human cornea to obtain a solid model that represents a personalized and in vivo morphology of both the anterior and posterior corneal surfaces. This model is later analyzed to obtain geometric variables enabling the characterization of the corneal geometry and establishing a new clinical diagnostic criterion in order to distinguish between healthy corneas and corneas with keratoconus. METHOD The method for the geometric reconstruction of the cornea consists of the following steps: capture and preprocessing of the spatial point clouds provided by the Sirius topographer that represent both anterior and posterior corneal surfaces, reconstruction of the corneal geometric surfaces and generation of the solid model. Later, geometric variables are extracted from the model obtained and statistically analyzed to detect deformations of the cornea. RESULTS The variables that achieved the best results in the diagnosis of keratoconus were anterior corneal surface area (ROC area: 0.847, p<0.000, std. error: 0.038, 95% CI: 0.777 to 0.925), posterior corneal surface area (ROC area: 0.807, p<0.000, std. error: 0.042, 95% CI: 0,726 to 0,889), anterior apex deviation (ROC area: 0.735, p<0.000, std. error: 0.053, 95% CI: 0.630 to 0.840) and posterior apex deviation (ROC area: 0.891, p<0.000, std. error: 0.039, 95% CI: 0.8146 to 0.9672). CONCLUSION Geometric modeling enables accurate characterization of the human cornea. Also, from a clinical point of view, the procedure described has established a new approach for the study of eye-related diseases.
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Affiliation(s)
- Francisco Cavas-Martínez
- Department of Graphical Expression, Technical University of Cartagena, Cartagena, Spain
- * E-mail:
| | | | | | - José Nieto Martínez
- Department of Graphical Expression, Technical University of Cartagena, Cartagena, Spain
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Savini G, Versaci F, Vestri G, Ducoli P, Næser K. Influence of posterior corneal astigmatism on total corneal astigmatism in eyes with moderate to high astigmatism. J Cataract Refract Surg 2014; 40:1645-53. [PMID: 25175270 DOI: 10.1016/j.jcrs.2014.01.046] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 11/16/2022]
Abstract
PURPOSE To evaluate the influence of posterior corneal astigmatism on total corneal astigmatism in patients with 1.00 diopter (D) or more of corneal astigmatism. SETTING Private practice, Bologna, Italy. DESIGN Prospective case series. METHODS Corneal astigmatism was measured using a Scheimpflug camera combined with a corneal topographer (Sirius). Keratometric astigmatism, anterior corneal astigmatism, posterior corneal astigmatism, and total corneal astigmatism were evaluated. Vector analysis was performed according to the Næser method. RESULTS One hundred fifty-seven eyes were enrolled. Keratometric astigmatism was with the rule (WTR), against the rule (ATR), and oblique in 84.0%, 11.5%, and 4.5% of eyes, respectively. Posterior corneal astigmatism exceeded 0.50 D and 1.00 D in 55.4% of eyes and 5.7% of eyes, respectively. The mean posterior corneal astigmatism was 0.54 D, inclined 91 degrees in relation to the steeper anterior corneal meridian. The steepest meridian was vertically aligned in 93.0% of cases. Compared with total corneal astigmatism, keratometric astigmatism overestimated WTR astigmatism by a mean of 0.22 D ± 0.32 (SD), underestimated ATR astigmatism by 0.21 ± 0.26 D, and overestimated oblique astigmatism by 0.13 ± 0.37 D. In the whole sample, a difference in astigmatism magnitude of 0.50 D or more was detected between keratometric astigmatism and total corneal astigmatism in 16.6% of cases and the difference in the location of the steep meridian was greater than 10 degrees in 3.8% of cases. CONCLUSION In patients who are candidates for surgical correction of astigmatism, measuring only the anterior corneal curvature can lead to inaccurate evaluation of the total corneal astigmatism. FINANCIAL DISCLOSURE Mr. Versaci and Mr. Vestri are employees of Costruzione Strumenti Oftalmici Srl. No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Giacomo Savini
- From the Studio Oculistico d'Azeglio (Savini), Bologna, G.B. Bietti Eye Foundation I.R.C.C.S. (Ducoli), Rome, and Costruzione Strumenti Oftalmici Srl (Versaci, Vestri), Florence, Italy; School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University (Savini), Wenzhou, Zhejiang, China; Regions Hospital Randers (Næser), Randers, Denmark.
| | - Francesco Versaci
- From the Studio Oculistico d'Azeglio (Savini), Bologna, G.B. Bietti Eye Foundation I.R.C.C.S. (Ducoli), Rome, and Costruzione Strumenti Oftalmici Srl (Versaci, Vestri), Florence, Italy; School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University (Savini), Wenzhou, Zhejiang, China; Regions Hospital Randers (Næser), Randers, Denmark
| | - Gabriele Vestri
- From the Studio Oculistico d'Azeglio (Savini), Bologna, G.B. Bietti Eye Foundation I.R.C.C.S. (Ducoli), Rome, and Costruzione Strumenti Oftalmici Srl (Versaci, Vestri), Florence, Italy; School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University (Savini), Wenzhou, Zhejiang, China; Regions Hospital Randers (Næser), Randers, Denmark
| | - Pietro Ducoli
- From the Studio Oculistico d'Azeglio (Savini), Bologna, G.B. Bietti Eye Foundation I.R.C.C.S. (Ducoli), Rome, and Costruzione Strumenti Oftalmici Srl (Versaci, Vestri), Florence, Italy; School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University (Savini), Wenzhou, Zhejiang, China; Regions Hospital Randers (Næser), Randers, Denmark
| | - Kristian Næser
- From the Studio Oculistico d'Azeglio (Savini), Bologna, G.B. Bietti Eye Foundation I.R.C.C.S. (Ducoli), Rome, and Costruzione Strumenti Oftalmici Srl (Versaci, Vestri), Florence, Italy; School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University (Savini), Wenzhou, Zhejiang, China; Regions Hospital Randers (Næser), Randers, Denmark
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Saenz-Frances F, Bermúdez-Vallecilla MC, Borrego-Sanz L, Jañez L, Martinez-de-la-Casa JM, Morales-Fernandez L, Santos-Bueso E, Garcia-Sanchez J, Garcia-Feijoo J. Anatomical characterization of central, apical and minimal corneal thickness. Int J Ophthalmol 2014; 7:668-72. [PMID: 25161940 DOI: 10.3980/j.issn.2222-3959.2014.04.15] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 03/12/2014] [Indexed: 11/02/2022] Open
Abstract
AIM To anatomically locate the points of minimum corneal thickness and central corneal thickness (pupil center) in relation to the corneal apex. METHODS Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex (AT), minimum corneal thickness (MT) and corneal thickness at the pupil center (PT) were determined using the pentacam. Distances from the corneal apex to MT (MD) and PT (PD) were calculated and their quadrant position (taking the corneal apex as the reference) determined: point of minimum thickness (MC) and point of central thickness (PC) depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume (determined using the Pentacam) and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models. RESULTS MT was located at a mean distance of 0.909 mm from the apex (79.4% in the inferior-temporal quadrant). PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume (B=-0.024; 95%CI: -0.043 to -0.004). No significant relations were identified in the linear regression model for PD or the multinomial logistic regressions for MC and PC. CONCLUSION MT was typically located at the inferior-temporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.
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Affiliation(s)
- Federico Saenz-Frances
- Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain
| | | | - Lara Borrego-Sanz
- Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Luis Jañez
- Instituto de Tecnología del Conocimiento, Universidad Complutense de Madrid, Madrid 28040, Spain
| | | | - Laura Morales-Fernandez
- Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Enrique Santos-Bueso
- Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Julián Garcia-Sanchez
- Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Julián Garcia-Feijoo
- Department of Ophthalmology, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid 28040, Spain
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Maresca N, Zeri F, Palumbo P, Calossi A. Agreement and reliability in measuring central corneal thickness with a rotating Scheimpflug-Placido system and ultrasound pachymetry. Cont Lens Anterior Eye 2014; 37:442-6. [PMID: 25151203 DOI: 10.1016/j.clae.2014.07.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 06/20/2014] [Accepted: 07/21/2014] [Indexed: 01/27/2023]
Abstract
PURPOSE We compare the agreement and the reliability in measuring central corneal thickness (CCT) using two different technologies. METHOD The right eyes of 35 healthy individuals who had a negative history of ophthalmic disease, or ocular surgery were examined. The CCT was determined sequentially with a rotating Scheimpflug camera (Sirius; CSO), and an ultrasound pachymeter (P-1; Takagi). For statistical analysis, we used the methods suggested by Bland and Altman. RESULTS The mean values of CCT obtained from Sirius, and ultrasound were 537±28μm, and 550±35μm, respectively. There was a high correlation between Sirius and ultrasound (r=0.92; p<0.001), but the difference between the two measurements was statistically significant (t=-5.7; p<0.00001). The precision of Sirius and ultrasound were 9.4 and 15.9μm; repeatability 13.3 and 22.4μm, and coefficient of variation 0.9% and 1.5%, respectively. The intraclass correlation coefficient was 0.97 for Sirius and 0.95 for ultrasound. CONCLUSIONS The average difference between corneal thickness measured with Sirius and ultrasound pachymetry was small but clinically significant. This means that the two instruments cannot be used interchangeably. Sirius showed precision and repeatability almost twice as much as ultrasound pachymetry. Confidence interval of 13.3μm for Sirius can show variations in corneal thickness with an uncertainty value lower than 2.5% in 95% of cases. The simplicity of use, the possibility to obtain pachymetric maps, and less invasiveness make this instrument potentially useful in contact lens practice.
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Affiliation(s)
- Nunzio Maresca
- Degree Course in Optics and Optometry, Faculty of Mathematics, Physics and Natural Sciences, Roma TRE University, Rome, Italy.
| | - Fabrizio Zeri
- Degree Course in Optics and Optometry, Faculty of Mathematics, Physics and Natural Sciences, Roma TRE University, Rome, Italy
| | - Paolo Palumbo
- Degree Course in Optics and Optometry, Faculty of Mathematics, Physics and Natural Sciences, Roma TRE University, Rome, Italy; Ospedale "Grassi" Roma, Italy
| | - Antonio Calossi
- Department of Physics (Optics and Optometry), University of Florence, Italy
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New approach for correction of error associated with keratometric estimation of corneal power in keratoconus. Cornea 2014; 33:960-7. [PMID: 25090162 DOI: 10.1097/ico.0000000000000190] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to obtain the exact value of the keratometric index (nkexact) and to clinically validate a variable keratometric index (nkadj) that minimizes this error. METHODS The nkexact value was determined by obtaining differences (ΔPc) between keratometric corneal power (Pk) and Gaussian corneal power ((Equation is included in full-text article.)) equal to 0. The nkexact was defined as the value associated with an equivalent difference in the magnitude of ΔPc for extreme values of posterior corneal radius (r2c) for each anterior corneal radius value (r1c). This nkadj was considered for the calculation of the adjusted corneal power (Pkadj). Values of r1c ∈ (4.2, 8.5) mm and r2c ∈ (3.1, 8.2) mm were considered. Differences of True Net Power with (Equation is included in full-text article.), Pkadj, and Pk(1.3375) were calculated in a clinical sample of 44 eyes with keratoconus. RESULTS nkexact ranged from 1.3153 to 1.3396 and nkadj from 1.3190 to 1.3339 depending on the eye model analyzed. All the nkadj values adjusted perfectly to 8 linear algorithms. Differences between Pkadj and (Equation is included in full-text article.)did not exceed ±0.7 D (Diopter). Clinically, nk = 1.3375 was not valid in any case. Pkadj and True Net Power and Pk(1.3375) and Pkadj were statistically different (P < 0.01), whereas no differences were found between (Equation is included in full-text article.)and Pkadj (P > 0.01). CONCLUSIONS The use of a single value of nk for the calculation of the total corneal power in keratoconus has been shown to be imprecise, leading to inaccuracies in the detection and classification of this corneal condition. Furthermore, our study shows the relevance of corneal thickness in corneal power calculations in keratoconus.
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Piñero DP. Technologies for anatomical and geometric characterization of the corneal structure and anterior segment: a review. Semin Ophthalmol 2013; 30:161-70. [PMID: 24175646 DOI: 10.3109/08820538.2013.835844] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Corneal and anterior segment imaging techniques have become a crucial tool in the clinical practice of ophthalmology, with a great variety of applications, such as corneal curvature and pachymetric analysis, detection of ectatic corneal conditions, anatomical study of the anterior segment prior to phakic intraocular lens implantation, or densitometric analysis of the crystalline lens. From the Placido-based systems that allow only a characterization of the geometry of the anterior corneal surface to the Scheimpflug photography-based systems that provide a characterization of the cornea, anterior chamber, and crystalline lens, there is a great variety of devices with the capability of analyzing different anatomical parameters with very high precision. To date, Scheimpflug photography-based systems are the devices providing the more complete analysis of the anterior segment in a non-invasive way. More developments are required in anterior segment imaging technologies in order to improve the analysis of the crystalline lens structure as well as the ocular structures behind the iris in a non-invasive way when the pupil is not dilated.
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Affiliation(s)
- David P Piñero
- Department of Ophthalmology (Oftalmar), Medimar International Hospital , Alicante , Spain
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Correlation of the corneal toricity between anterior and posterior corneal surfaces in the normal human eye. Cornea 2013; 32:791-8. [PMID: 23328698 DOI: 10.1097/ico.0b013e31827bf898] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To evaluate the correlation of the magnitude of corneal toricity and power vector components of both corneal surfaces measured with a Scheimpflug photography-based system. METHODS A total of 117 healthy normal eyes of 117 subjects selected randomly with ages ranging from 7 to 80 years were included. All eyes received an anterior segment and corneal analysis with the Sirius system (CSO) evaluating the anterior and posterior mean toricity for 3 and 7 mm (aAST and pAST). The vector components J0 and J45 as well as the overall strength blur (B) were calculated for each keratometric measurement using the procedure defined by Thibos and Horner. RESULTS The coefficient of correlation between aAST and pAST was 0.52 and 0.62 and the mean anteroposterior ratio for toricity was 0.46 ± 0.39 and 0.57 ± 0.75 for 3 and 7 mm, respectively. These ratios correlated significantly with aAST, anterior corneal J0, and manifest refraction J0 (r ≥ 0.39, P < 0.01). The coefficient of correlation was 0.69 and 0.81 between anterior and posterior J0 for 3 and 7 mm, respectively. For J45, the coefficients were 0.62 and 0.71, respectively. The linear regression analysis revealed that the pAST and power vectors could be predicted from the anterior corneal data (R2 ≥ 0.40, P < 0.01). CONCLUSIONS The toricity and astigmatic power vector components of the posterior corneal surface in the human healthy eye are related to those of the anterior and therefore can be predicted consistently from the anterior toricity and astigmatic power vectors.
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Huang J, Lu W, Savini G, Hu L, Pan C, Wang J, Tan W, Chen J, Wang Q. Evaluation of corneal thickness using a Scheimpflug-Placido disk corneal analyzer and comparison with ultrasound pachymetry in eyes after laser in situ keratomileusis. J Cataract Refract Surg 2013; 39:1074-80. [PMID: 23680632 DOI: 10.1016/j.jcrs.2013.01.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 01/26/2013] [Accepted: 01/31/2013] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the repeatability and reproducibility of corneal thickness measurements in post-laser in situ keratomileusis (LASIK) eyes using a rotating Scheimpflug camera combined with a Placido disk corneal topographer (Sirius) and compare the results with those of ultrasound (US) pachymetry. SETTING Eye Hospital of Wenzhou Medical College, Wenzhou, China. DESIGN Comparative evaluation of a diagnostic test or technology. METHODS Patients were examined 3 times with the Scheimpflug-Placido topographer by 2 examiners. The central pupil corneal thickness (CTpupil), apical corneal thickness (CTapex), and thinnest corneal thickness (CTthinnest) were recorded. After noncontact examinations, US pachymetry was used to obtain the central corneal thickness (CCT). RESULTS The Scheimpflug-Placido topographer showed high intraoperator repeatability as indicated by a test-retest repeatability of less than 8.5 μm for CTpupil, CTapex, and CTthinnest, The coefficients of variation (CoV) were less than 0.7%, and the intraclass correlation coefficient was higher than 0.99. Excellent results were also obtained for interoperator reproducibility. All CoVs were less than 0.5%. The 95% limits of agreement between the Scheimpflug-Placido measurement and the US pachymetry measurements were narrow (-16.62 to 12.44 μm for CTpupil versus US pachymetry CCT; -17.49 to 12.16 μm for CTapex versus US pachymetry CCT; -18.59 to 10.90 μm for CTthinnest versus US pachymetry CCT). CONCLUSIONS The Scheimpflug-Placido topographer showed excellent intraoperator repeatability and interoperator reproducibility of CTpupil, CTapex, and CTthinnest measurements in post-LASIK eyes. The CCT measurements obtained using the device were in high agreement with those obtained by US pachymetry, suggesting that the 2 devices are interchangeable. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Jinhai Huang
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical College, and the Key Laboratory of Vision Science, Ministry of Health PR China, Wenzhou, Zhejiang, China
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Huang J, Savini G, Hu L, Hoffer KJ, Lu W, Feng Y, Yang F, Hu X, Wang Q. Precision of a new Scheimpflug and Placido-disk analyzer in measuring corneal thickness and agreement with ultrasound pachymetry. J Cataract Refract Surg 2013; 39:219-24. [PMID: 23218819 DOI: 10.1016/j.jcrs.2012.10.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 10/09/2012] [Accepted: 10/12/2012] [Indexed: 10/27/2022]
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Montalbán R, Alio JL, Javaloy J, Piñero DP. Comparative analysis of the relationship between anterior and posterior corneal shape analyzed by Scheimpflug photography in normal and keratoconus eyes. Graefes Arch Clin Exp Ophthalmol 2013; 251:1547-55. [PMID: 23334367 DOI: 10.1007/s00417-013-2261-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 12/16/2012] [Accepted: 01/03/2013] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND To analyze and compare the relationship between anterior and posterior corneal shape evaluated by a tomographic system combining the Scheimpflug photography and Placido-disc in keratoconus and normal healthy eyes, as well as to evaluate its potential diagnostic value. METHODS Comparative case series including a sample of 161 eyes of 161 subjects with ages ranging from 7 to 66 years and divided into two groups: normal group including 100 healthy eyes of 100 subjects, and keratoconus group including 61 keratoconus eyes of 61 patients. All eyes received a comprehensive ophthalmologic examination including an anterior segment analysis with the Sirius system (CSO). Antero-posterior ratios for corneal curvature (k ratio) and shape factor (p ratio) were calculated. Logistic regression analysis was used to evaluate if some antero-posterior ratios combined with other clinical parameters were predictors of the presence of keratoconus. RESULTS No statistically significant differences between groups were found in the antero-posterior k ratios for 3-, 5- and 7-mm diameter corneal areas (p ≥ 0.09). The antero-posterior p ratio for 4.5- and 8-mm diameter corneal areas was significantly higher in the normal group than in the keratoconus group (p<0.01). The k ratio for 3, 5, and 7 mm was significantly higher in the keratoconus grade IV subgroup than in the normal group (p<0.01). Furthermore, significant differences were found in the p ratio between the normal group and the keratoconus grade II subgroup (p ≤ 0.01). Finally, the logistic regression analysis identified as significant independent predictors of the presence of keratoconus (p<0.01) the 8-mm anterior shape factor, the anterior chamber depth, and the minimal corneal thickness. CONCLUSIONS The antero-posterior k and p ratios are parameters with poor prediction ability for keratoconus, in spite of the trend to the presence of more prolate posterior corneal surfaces compared to the anterior in keratoconus eyes.
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Affiliation(s)
- Raúl Montalbán
- Instituto Oftalmológico de Alicante, Vissum Corporation, Alicante, Spain
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Intrasubject repeatability in keratoconus-eye measurements obtained with a new Scheimpflug photography-based system. J Cataract Refract Surg 2012; 39:211-8. [PMID: 23218818 DOI: 10.1016/j.jcrs.2012.10.033] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 10/05/2012] [Accepted: 10/05/2012] [Indexed: 11/22/2022]
Abstract
PURPOSE To evaluate in keratoconus eyes the intrasubject repeatability of anterior and posterior corneal curvature and of other anterior segment anatomic measurements obtained with a new topography system combining Scheimpflug-photography and Placido-disk technology. SETTING Vissum Corporation, Alicante, Spain. DESIGN Evaluation of technology. METHODS All keratoconus eyes had a comprehensive ophthalmologic examination including analysis with the Sirius system. Three consecutive measurements were obtained to assess the intrasubject repeatability of the following parameters: anterior and posterior corneal curvature and shape factor, white-to-white (WTW) corneal diameter, central and minimum corneal thickness, and anterior chamber depth (ACD). The within-subject standard deviation (S(w)) and intraclass correlation coefficient (ICC) were calculated. RESULTS This study comprised 61 eyes of 61 patients ranging in age from 14 to 64 years. For anterior and posterior corneal curvatures and power vector components, the S(w) was 0.29 mm or less in all cases. The ICC was above 0.990 in all cases except the flattest curvature of the posterior corneal surface at 3.0 mm, which was 0.840 (moderate agreement), and the posterior power vector J0, which was 0.665 (poor agreement), 0.752, and 0.758 (moderate agreement) for 3.0 mm, 5.0 mm, and 7.0 mm, respectively. In shape factor measurements, the S(w) was 0.12 or less in all cases and the ICC ranged between 0.989 and 0.999. Pachymetry, ACD, and WTW had ICC values very close to 1. CONCLUSION The new topography system provided repeatable measurements of corneal shape and other anatomic parameters in eyes with keratoconus. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Montalbán R, Piñero DP, Javaloy J, Alió JL. Scheimpflug photography-based clinical characterization of the correlation of the corneal shape between the anterior and posterior corneal surfaces in the normal human eye. J Cataract Refract Surg 2012; 38:1925-33. [PMID: 22981614 DOI: 10.1016/j.jcrs.2012.06.050] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 06/14/2012] [Accepted: 06/19/2012] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the correlation of the mean curvature and shape factors between both corneal surfaces for different corneal diameters measured with a Scheimpflug photography-based system. SETTING Vissum Corporation, Alicante, Spain. DESIGN Case series. METHODS Randomly selected healthy normal eyes had a comprehensive ophthalmologic examination including anterior segment analysis with the Sirius system as follows: anterior and posterior mean corneal radius for 3.0 mm, 5.0 mm, and 7.0 mm; anterior and posterior mean shape factor for 4.5 mm and 8.0 mm; central (CCT) and minimum corneal thickness; and anterior chamber depth (ACD). RESULTS The study enrolled 117 eyes (117 subjects; aged 7 to 80 years). The mean anterior mean corneal radius:posterior mean corneal radius ratio was 1.19 (range 1.12 to 1.27) for all corneal diameters (P = .86). The correlation coefficient between the anterior and posterior mean corneal radius was 0.85 or more for all corneal diameters. The anterior mean shape factor:posterior mean shape factor ratio for the 2 corneal diameters analyzed was approximately 1 (range 0.45 to 4.03). The correlations between anterior and posterior mean shape factors were extremely poor and not significant. Multiple regression analysis showed that the central posterior mean corneal radius was significantly correlated with the anterior mean corneal radius, CCT, and spherical equivalent (R(2) = 0.77, P<.01). CONCLUSIONS Central posterior corneal curvature could be predicted from the anterior corneal curvature, pachymetry, and the refractive status of the eye but not from the corneal shape factor. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Raúl Montalbán
- Instituto Oftalmológico de Alicante, Universidad de Alicante, Alicante, Spain
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