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Haworth K, Travis D, Leslie L, Fuller D, Pucker AD. Silicone hydrogel versus hydrogel soft contact lenses for differences in patient-reported eye comfort and safety. Cochrane Database Syst Rev 2023; 9:CD014791. [PMID: 37724689 PMCID: PMC10507745 DOI: 10.1002/14651858.cd014791.pub2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
BACKGROUND Ocular discomfort is the leading cause of permanent discontinuation of soft contact lens (SCL) wear. Silicone hydrogel and hydrogel materials are the two major categories of SCLs, with silicone hydrogel materials being newer and more breathable than hydrogel materials. Whether comfort is associated with SCL material is controversial despite numerous studies. Similarly, the difference between these materials in terms of safety outcomes (e.g. frequency of microbial keratitis) is unclear. OBJECTIVES To evaluate the comparative effectiveness and safety of silicone hydrogel compared with hydrogel SCLs on self-reported comfort, dry eye test results, and adverse events in SCL-wearing adults 18 years of age or older. SEARCH METHODS The Cochrane Eyes and Vision Information Specialist searched the electronic databases for randomized controlled trials (RCTs). There were no restrictions on language or date of publication. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, including the Cochrane Eyes and Vision Trials Register; 2022, Issue 6), MEDLINE Ovid, Embase.com, PubMed, LILACS (Latin American and Caribbean Health Science Information database), ClinicalTrials.gov, and World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We also searched the reference lists of identified studies, review articles, and guidelines for information about relevant studies that may not have been identified by our search strategy. Furthermore, we contacted investigators regarding ongoing trials. The most recent database search was conducted on 24 June 2022. SELECTION CRITERIA Our search selection criteria included RCTs, quasi-RCTs, and cross-over RCTs. DATA COLLECTION AND ANALYSIS We applied standard Cochrane methodology. MAIN RESULTS We included seven parallel-group RCTs conducted in the USA, the UK, Australia, Germany, India, and Turkey. A total of 1371 participants were randomized. The duration of SCL wear ranged from one to 52 weeks. Study characteristics and risk of bias The median number of participants per trial was 120 (interquartile range: 51 to 314), and the average age ranged from 20.7 to 33.0 years. Women represented the majority of participants (range 55% to 74.9%; 5 RCTs). Collectively, the included trials compared eight different silicone hydrogel SCLs with three different hydrogel SCLs. Five trials compared daily disposable SCLs, and two compared extended wear SCLs (worn for seven days and six nights). New SCL wearers were enrolled in three trials. Two trials included both new and established SCL wearers, and two trials did not report participants' history of SCL use. Five trials were sponsored by industry. We judged the overall risk of bias to be 'high' or 'some concerns' for the safety and efficacy outcomes. Findings One trial reported Ocular Surface Disease Index (OSDI) results, with the evidence being very uncertain about the effects of SCL material on OSDI scores (mean difference -1.20, 95% confidence interval [CI] -10.49 to 8.09; 1 RCT, 47 participants; very low certainty evidence). Three trials reported visual analog scale comfort score results, with no clear difference in comfort between materials, but the evidence was of very low certainty; trial results could not be combined because the three trials reported results at different time points. The evidence is very uncertain about the effect of SCL material on discontinuation of contact lens wear (risk ratio [RR] 0.64, 95% CI 0.11 to 3.74; 1 RCT, 248 participants). None of the included trials reported Contact Lens Dry Eye Questionnaire (CLDEQ-8) or Standard Patient Evaluation of Eye Dryness (SPEED) scores. There was no evidence of a clinically meaningful difference (> 0.5 unit) between daily disposable silicone hydrogel and hydrogel SCLs in corneal staining, conjunctival staining, or conjunctival redness (very low certainty evidence). Adverse events Very low certainty evidence from two trials comparing daily disposable SCLs suggested no evidence of a difference between lens materials in the risk of vision-threatening adverse events at one to four weeks (RR 0.68, 95% CI 0.08 to 5.51; 2 RCTs, 368 participants). Two trials comparing extended wear SCLs indicated that hydrogel SCLs may have a 2.03 times lower risk of adverse events at 52 weeks compared with silicone hydrogel SCLs (RR 2.03, 95% CI 1.38 to 2.99; 815 participants), but the certainty of evidence was very low. AUTHORS' CONCLUSIONS The overall evidence for a difference between all included silicone hydrogel and hydrogel SCLs was of very low certainty, with most trials at high overall risk of bias. The majority of studies did not assess comfort using a validated instrument. There was insufficient evidence to support recommending one SCL material over the other. For extended wear, hydrogel SCL may have a lower risk of adverse events at 52 weeks compared to silicon hydrogel. Future well-designed trials are needed to generate high certainty evidence to further clarify differences in SCL material comfort and safety.
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Affiliation(s)
| | - Darian Travis
- School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Louis Leslie
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Daniel Fuller
- Cornea Contact Lens Service, The Eye Center, Southern College of Optometry, Memphis, TN, USA
| | - Andrew D Pucker
- School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Yu AY, Ye J, Savini G, Wang Y, Zhang T, Chen M, Wang Q, Huang J. Reliability and agreement of the central and mid-peripheral corneal thickness measured by a new Scheimpflug based imaging. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1136. [PMID: 34430577 PMCID: PMC8350684 DOI: 10.21037/atm-20-7895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 04/24/2021] [Indexed: 11/06/2022]
Abstract
Background To assess the intra-observer repeatability and inter-observer reproducibility of central corneal thickness (CCT) and mid-peripheral corneal thickness (MPCT) measurements using a new Scheimpflug imaging instrument (Scansys) and compare the agreement with the rotating Scheimpflug corneal tomographer (Pentacam HR). Methods The same well-trained operator performed the measuring using the two devices, after which Scansys measurements were repeated by another operator. Both instruments required three consecutive measurements per subject. Corneal thickness measurements were obtained by each instrument, including CCT, thinnest corneal thickness (TCT), pupil corneal thickness (PCT), and MPCT. Test-retest repeatability (TRT), within-subject coefficient of variation (CoV), and intra-class correlation coefficient (ICC) were used to evaluate repeatability and reproducibility. A paired t-test was used to compare the differences between Scansys and Pentacam, and the agreement was compared with Bland-Altman plots. Results This study enrolled 112 healthy subjects. The CoV were <0.91% and 0.55% for repeatability and reproducibility, respectively. The ICC was close to 1 in all measurements. For intra-observer repeatability in the CT2mm region, TRT was <10.30 µm. Moreover, TRT was <15.26 µm within the CT5mm region. The paired t-test showed significant differences in all corneal thickness measurements (P<0.001). The central region and CT2mm agreement were high, but the largest range of 95% limits of agreement (LoA) appeared in the CTnasal-5mm. Conclusions The new Scheimpflug imaging instrument showed excellent intra-observer repeatability and inter-observer reproducibility for corneal thickness measurements. The agreement analysis suggested that Scansys and Pentacam could be interchangeably used between the central region and CT2mm, except CT5mm.
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Affiliation(s)
- A-Yong Yu
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Junming Ye
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | | | - Yiran Wang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Tianjiao Zhang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Min Chen
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China
| | - Qinmei Wang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Jinhai Huang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
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Martin R, Nuñez L, Sastre J, De juan V, Rodriguez G. Constancy of the Orbscan acoustic factor to detect contact lens‐induced corneal swelling. Clin Exp Optom 2021; 94:352-60. [DOI: 10.1111/j.1444-0938.2010.00578.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Raul Martin
- IOBA‐Eye Institute and School of Optometry, Department of Physics TAO, University of Valladolid, Valladolid, Spain
E‐mail:
| | - Laura Nuñez
- IOBA‐Eye Institute and School of Optometry, Department of Physics TAO, University of Valladolid, Valladolid, Spain
E‐mail:
| | - Jesus Sastre
- IOBA‐Eye Institute and School of Optometry, Department of Physics TAO, University of Valladolid, Valladolid, Spain
E‐mail:
| | - Victoria De juan
- IOBA‐Eye Institute and School of Optometry, Department of Physics TAO, University of Valladolid, Valladolid, Spain
E‐mail:
| | - Guadalupe Rodriguez
- IOBA‐Eye Institute and School of Optometry, Department of Physics TAO, University of Valladolid, Valladolid, Spain
E‐mail:
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Martin R, Rachidi H. Stability of posterior corneal elevation one year after myopic laser in situ keratomileusis. Clin Exp Optom 2021; 95:177-86. [DOI: 10.1111/j.1444-0938.2011.00665.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Raul Martin
- IOBA‐Eye Institute and Department of Physics TAO, University of Valladolid, Valladolid, Spain. E‐mail:
| | - Houda Rachidi
- IOBA‐Eye Institute and Department of Physics TAO, University of Valladolid, Valladolid, Spain. E‐mail:
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Kim YH, Lin MC, Radke CJ. Limbal Metabolic Support Reduces Peripheral Corneal Edema with Contact-Lens Wear. Transl Vis Sci Technol 2020; 9:44. [PMID: 32832249 PMCID: PMC7414613 DOI: 10.1167/tvst.9.7.44] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 04/14/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To assess the influence of limbal metabolic support on corneal edema during scleral-lens (SL) and soft-contact-lens (SCL) wear for healthy lens wearers. Methods A two-dimensional (2D) model of the cornea and sclera was designed on Comsol Multiphysics 5.4 along with SL and SCL architectures to mimic lens-wear induced hypoxia. The cornea is suffused with oxygen and metabolites from the limbus and aqueous humor. Air oxygen is supplied from and carbon dioxide is expelled to the atmosphere. Lens-oxygen permeability (Dk) was adjusted to investigate lens-wear safety against edema in different wear conditions. The 2D concentrations of oxygen, carbon dioxide, bicarbonate, lactate, sodium, chloride, glucose, and pH are quantified. Central-to-peripheral swelling of the cornea is determined by the change in stromal hydration caused by changing metabolite concentrations at the endothelium during hypoxia. Results The metabolic model assesses central-to-peripheral corneal swelling with different types of lenses, and oxygen Dks. Limbal metabolic support reduces edema from the periphery to approximately 1 mm away from the central cornea. Despite thicker lens designs, the peripheral cornea exhibits practically zero swelling due to limbal metabolic support. Conclusions The metabolic model accurately predicts central-to-peripheral corneal edema with various contact-lens designs, post-lens tear-film thicknesses, and lens oxygen Dk values. Despite the thicker periphery of most contact-lens designs, lactate and bicarbonate support from the limbus significantly reduces peripheral and mid-peripheral corneal edema, whereas oxygen has a lesser effect. Translational Relevance By utilizing metabolic kinetics, we provide a 2D computational tool to predict oxygenation safety across the entire cornea with various types and designs of contact lenses.
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Affiliation(s)
- Young Hyun Kim
- Vision Science Group, University of California, Berkeley, CA, USA.,Chemical and Biomolecular Engineering Department, University of California, Berkeley, CA, USA.,Clinical Research Center, School of Optometry, University of California, Berkeley, CA, USA
| | - Meng C Lin
- Vision Science Group, University of California, Berkeley, CA, USA.,Clinical Research Center, School of Optometry, University of California, Berkeley, CA, USA
| | - Clayton J Radke
- Vision Science Group, University of California, Berkeley, CA, USA.,Chemical and Biomolecular Engineering Department, University of California, Berkeley, CA, USA
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Martin R. Cornea and anterior eye assessment with placido-disc keratoscopy, slit scanning evaluation topography and scheimpflug imaging tomography. Indian J Ophthalmol 2018; 66:360-366. [PMID: 29480244 PMCID: PMC5859588 DOI: 10.4103/ijo.ijo_850_17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 09/28/2017] [Indexed: 12/11/2022] Open
Abstract
Current corneal assessment technologies make the process of corneal evaluation extremely fast and simple and several devices and technologies allow to explore and to manage patients. The purpose of this special issue is to present and also to update in the evaluation of cornea and ocular surface and this second part, reviews a description of the corneal topography and tomography techniques, providing updated information of the clinical recommendations of these techniques in eye care practice. Placido-based topographers started an exciting anterior corneal surface analysis that allows the development of current corneal tomographers that provide a full three-dimensional reconstruction of the cornea including elevation, curvature, and pachymetry data of anterior and posterior corneal surfaces. Although, there is not an accepted reference standard technology for corneal topography description and it is not possible to determine which device produces the most accurate topographic measurements, placido-based topographers are a valuable technology to be used in primary eye care and corneal tomograhers expanding the possibilities to explore cornea and anterior eye facilitating diagnosis and follow-up in several situations, raising patient follow-up, and improving the knowledge regarding to the corneal anatomy. Main disadvantages of placido-based topographers include the absence of information about the posterior corneal surface and limited corneal surface coverage without data from the para-central and/or peripheral corneal surface. However, corneal tomographers show repeatable anterior and posterior corneal surfaces measurements, providing full corneal thickness data improving cornea, and anterior surface assessment. However, differences between devices suggest that they are not interchangeable in clinical practice.
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Affiliation(s)
- Raul Martin
- Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, Valladolid, Spain
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain
- IOBA Eye Institute, School of Optometry, University of Valladolid, Valladolid, Spain
- Faculty of Health and Human Sciences, Plymouth University, PL6 8BH Plymouth, United Kingdom
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Repeatability of Pentacam peripheral corneal thickness measurements. Cont Lens Anterior Eye 2015; 38:424-9. [DOI: 10.1016/j.clae.2015.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 04/01/2015] [Accepted: 05/13/2015] [Indexed: 11/18/2022]
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Khaja WA, Grover S, Kelmenson AT, Ferguson LR, Sambhav K, Chalam KV. Comparison of central corneal thickness: ultrasound pachymetry versus slit-lamp optical coherence tomography, specular microscopy, and Orbscan. Clin Ophthalmol 2015; 9:1065-70. [PMID: 26109840 PMCID: PMC4472076 DOI: 10.2147/opth.s81376] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Central corneal thickness (CCT) can be measured by using contact and non-contact methods. Ultrasound pachymetry (US pachymetry) is a contact method for measuring CCT and is perhaps the most commonly used method. However, non-contact methods like scanning slit topography (Orbscan II), slit-lamp optical coherence tomography (SL-OCT), and specular microscopy are also used. Not many studies have correlated the measurement of CCT with all four modalities. The purpose of this study was to compare and correlate the CCT measurements obtained by US pachymetry with SL-OCT, specular microscopy, and Orbscan. Method This is a prospective, comparative study done in an institutional setting. Thirty-two eyes of 32 subjects with no known ocular disease and best-corrected visual acuity of 20/20 were enrolled. CCT measurements were obtained using SL-OCT, specular microscopy, scanning slit topography (Orbscan), and US pachymetry. Three measurements were made with each instrument by the same operator. Mean, standard deviation, and coefficient of variation were calculated for CCT measurements acquired by the four measurement devices. Bland–Altman plot was constructed to determine the agreements between the CCT measurements obtained by different equipment. Results The mean CCT was 548.16±48.68 μm by US pachymetry. In comparison, CCT averaged 546.36±44.17 μm by SL-OCT, 557.61±49.92 μm by specular microscopy, and 551.03±48.96 μm by Orbscan for all subjects. Measurements by the various modalities were strongly correlated. Correlations (r2) of CCT, as measured by US pachymetry compared with other modalities, were: SL-OCT (r2=0.98, P<0.0001), specular microscopy (r2=0.98, P<0.0001), and Orbscan (r2=0.96, P<0.0001). All modalities had a linear correlation with US pachymetry measurements. Conclusion In subjects with healthy corneas, SL-OCT, specular microscopy, and Orbscan (with correction factor) can be used interchangeably with US pachymetry in certain clinical settings. The four modalities showed significant linear correlations with one another.
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Affiliation(s)
- Wassia A Khaja
- Department of Ophthalmology, University of Florida, College of Medicine, Jacksonville, FL, USA
| | - Sandeep Grover
- Department of Ophthalmology, University of Florida, College of Medicine, Jacksonville, FL, USA
| | - Amy T Kelmenson
- Department of Ophthalmology, University of Florida, College of Medicine, Jacksonville, FL, USA
| | - Lee R Ferguson
- Department of Ophthalmology, University of Florida, College of Medicine, Jacksonville, FL, USA
| | - Kumar Sambhav
- Department of Ophthalmology, University of Florida, College of Medicine, Jacksonville, FL, USA
| | - Kakarla V Chalam
- Department of Ophthalmology, University of Florida, College of Medicine, Jacksonville, FL, USA
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Otero C, Vilaseca M, Arjona M, Martínez-Roda JA, Pujol J. Repeatability of aberrometric measurements with a new instrument for vision analysis based on adaptive optics. J Refract Surg 2015; 31:188-94. [PMID: 25751836 DOI: 10.3928/1081597x-20150224-03] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 01/19/2015] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate intersession and intrasession repeatability of aberration data obtained with a new visual simulator based on adaptive optics, which includes a Hartmann-Shack aberrometer (Adaptive Optics Vision Analyzer; Voptica S.L., Murcia, Spain). METHODS Thirty-one healthy right eyes were included in the study. To evaluate intrasession repeatability, three consecutive measurements without repositioning the patient or realigning the eye were obtained. Intersession repeatability was evaluated in three sessions. Aberrometric data computed from the second to the fifth order for a 4-mm pupil were used. Statistical analysis included the repeated measures analysis of variance (or the Wilcoxon signed rank test), the coefficient of repeatability, the Bland-Altman method, and the intraclass correlation coefficient. RESULTS No significant differences in the intrasession and intersession repeatability analysis for any of the parameters (P > .05) were found, suggesting a consistent variability of the instrument over time. Similar coefficient of repeatability values were obtained in the three sessions. The Bland-Altman analysis confirmed differences close to zero and the variations were independent of the mean within and between sessions. The intersession intraclass correlation coefficient values were generally above 0.75, suggesting moderate to high repeatability. However, some exceptions were found in the intrasession analysis. CONCLUSIONS The findings suggest that the new instrument provides consistent and repeatable aberrometric data. It is therefore a suitable tool to perform consistent and repeatable visual simulations.
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Corneal assessment technologies: Current status. Surv Ophthalmol 2014; 59:599-614. [DOI: 10.1016/j.survophthal.2014.05.001] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 05/15/2014] [Accepted: 05/20/2014] [Indexed: 11/22/2022]
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Ortiz S, Mena L, Rio-San Cristobal A, Martin R. Relationships between central and peripheral corneal thickness in different degrees of myopia. JOURNAL OF OPTOMETRY 2014; 7:44-50. [PMID: 24646900 PMCID: PMC3938742 DOI: 10.1016/j.optom.2013.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/07/2013] [Accepted: 02/07/2013] [Indexed: 05/03/2023]
Abstract
PURPOSE To analyze the relationship between the central corneal thickness (CCT) and mid-peripheral corneal thickness (PCT) with the degree of myopia [axial length (AL) and spherical equivalent refractive error (SE)]. METHODS 175 right myopic eyes from 175 patients were divided according to the degree of SE: group #1 (n=76, <6.00 D), group #2 (n=72, between 6.00 and 12.00 D) and group #3 (n=27, >12.00 D). The CCT and PCT (3mm from the apex to the superior, inferior, nasal and temporal locations) were measured with the Orbscan-II. Relative peripheral index (RPI) was calculated by dividing the PCT by the CCT. The AL was measured with the IOL Master, and the SE was obtained with subjective refraction. RESULTS AL was 25.18±1.16 mm, 26.59±1.26 mm and 29.45±2.58 mm and SE was -3.31±1.40 D, -8.32±1.64 D and -16.44±4.48 D for groups #1, #2 and #3, respectively. Non-statistically significant differences in central and peripheral corneal thickness were found between groups (P>0.05 ANOVA). Non-significant relationship was found between central and peripheral corneal thickness with the AL and SE in the three study groups and in the total sample (r<0.24; P>0.05). The RPI values were similar between groups without significant difference between groups (P>0.05 ANOVA). Linear relationship was found between RPI superior location in group #2 (r=-0.23; P=0.04) and RPI nasal location in group #3 with the EE (r=0.41; P=0.03). CONCLUSION There are no significant differences among low, moderate and extremely myopic eyes related to the CCT and PCT. Corneal thickness is very similar in myopic eyes with small differences that are not clinically relevant to myopic patient management.
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Affiliation(s)
- Sara Ortiz
- Optometry Research Group, IOBA-Eye Institute, University of Valladolid, Valladolid, Spain
| | - Laura Mena
- Optometry Research Group, IOBA-Eye Institute, University of Valladolid, Valladolid, Spain
| | - Ana Rio-San Cristobal
- Optometry Research Group, IOBA-Eye Institute, University of Valladolid, Valladolid, Spain
| | - Raul Martin
- Optometry Research Group, IOBA-Eye Institute, University of Valladolid, Valladolid, Spain; Department of Physics TAO, School of Optometry, University of Valladolid, Valladolid, Spain.
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Almubrad TM, Osuagwu UL, AlAbbadi I, Ogbuehi KC. Comparison of the precision of the Topcon SP-3000P specular microscope and an ultrasound pachymeter. Clin Ophthalmol 2011; 5:871-6. [PMID: 21760714 PMCID: PMC3133003 DOI: 10.2147/opth.s21247] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Indexed: 11/23/2022] Open
Abstract
AIM To compare the precision of the Topcon SP-3000P noncontact specular microscope (NCSM) and the DGH 500 ultrasound pachymeter (USP). METHODS Triplicate measurements of central corneal thickness (CCT) for 100 eyes were taken with an NCSM and a USP in 2 visits separated by 1 week. Repeatability was assessed by computing the differences between all 3 readings from each subject. Coefficients of repeatability and reproducibility were computed. RESULTS MEAN CCT AS MEASURED BY EACH INSTRUMENT WERE: 518.53 ± 34.96 μm (range 417.33-592.67) and 516.94 ± 33.60 μm (range 431.67-582.67) for sessions 1 and 2 respectively, with the NCSM; 546.69 ± 36.62 μm (range 457.33-617.00) and 549.78 ± 35.26 μm (range 454.00-618.67) for sessions 1 and 2 respectively, with the USP. The ultrasound CCT measurements were consistently higher than those obtained with the NCSM in both sessions 28.17 ± 19.20 μm (mean ± SD, session 1) and 32.81 ± 14.04 (mean ± SD, session 2). The repeatability coefficient for the NCSM was better in both sessions than those for USP (±10 μm vs ± 12 μm in session 1 and ±8 μm vs ±10 μm in session 2). The reproducibility coefficient with the NCSM was half that with the USP (±21 μm vs ±41 μm). CONCLUSION The SP-3000P NCSM is a more precise and reproducible instrument for measurement of CCT than the USP, but both instruments are reliable, useful instruments for measuring CCT.
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Affiliation(s)
- Turki M Almubrad
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Uchechukwu L Osuagwu
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Ibrahim AlAbbadi
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Kelechi C Ogbuehi
- Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
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The Orbscan Acoustic (Correction) Factor for Central Corneal Thickness Measures of Normal Human Corneas. Eye Contact Lens 2010; 36:106-15. [DOI: 10.1097/icl.0b013e3181d0b604] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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