1
|
Bruttini C, Esposti R, Pece A, Maione G, Cavallari P. Comparison of central corneal thickness measured by automatic and manual analysis of optical coherence tomography. Graefes Arch Clin Exp Ophthalmol 2024; 262:1857-1863. [PMID: 38206413 DOI: 10.1007/s00417-023-06354-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/14/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
PURPOSE To compare central corneal thickness (CCT) measured with optical coherence tomography (OCT) using an automatic algorithm (A-OCT) vs. manual measurements (M-OCT) with respect to the gold standard ultrasound pachymetry (USP). METHODS CCT measurements were performed on both eyes of 28 healthy subjects at four times of the day. A-OCT used an automatic software analysis of the corneal image, M-OCT was performed by two operators by setting a digital calliper on the corneal borders, and USP was performed after corneal anesthesia. Measurements were compared using a three-way repeated measures ANOVA. Bland-Altman plots were used to evaluate the agreement between OCT measurements and USP. RESULTS Both A-OCT and M-OCT significantly underestimated the USP measures, with the mean difference, i.e., the systematic error, being larger for A-OCT (- 19.0 µm) than for M-OCT (- 6.5 µm). Good reproducibility between the two operators was observed. Bland-Altman plots showed that both OCT methods suffered from proportional errors, which were not affected by time and eye. CONCLUSIONS Measuring CCT with OCT yielded lower values than USP. Therefore, clinicians should be aware that corneal thickness values may be influenced by the measurement method and that the various devices should not be used interchangeably in following up a given patient. Intriguingly, M-OCT had less systematic error than A-OCT, an important outcome that clinicians should consider when deciding to use an OCT device.
Collapse
Affiliation(s)
- Carlo Bruttini
- University Eye Clinic, IRCCS, Policlinico San Matteo, Pavia, Italy.
- Eye Clinic, Melegnano Hospital, Via Pandina, 1, 20077, Vizzolo Predabissi, Italy.
| | - Roberto Esposti
- Human Physiology Section of the DePT, Università Degli Studi Di Milano, Milan, Italy
| | - Alfredo Pece
- Eye Clinic, Melegnano Hospital, Via Pandina, 1, 20077, Vizzolo Predabissi, Italy
| | - Giulio Maione
- Eye Clinic, Melegnano Hospital, Via Pandina, 1, 20077, Vizzolo Predabissi, Italy
| | - Paolo Cavallari
- Human Physiology Section of the DePT, Università Degli Studi Di Milano, Milan, Italy
| |
Collapse
|
2
|
Gupta SK, Dhakal R, Verkicharla PK. Biometry-Based Technique for Determining the Anterior Scleral Thickness: Validation Using Optical Coherence Tomography Landmarks. Transl Vis Sci Technol 2024; 13:25. [PMID: 38285460 PMCID: PMC10829803 DOI: 10.1167/tvst.13.1.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/22/2023] [Indexed: 01/30/2024] Open
Abstract
Purpose Considering the potential role of anterior scleral thickness (AST) in myopia and the ubiquitous use of optical biometers, we applied and validated a biometry-based technique for estimating AST using optical coherence tomography (OCT) landmarks. Methods The AST was determined across four meridians in 62 participants (aged 20-37 years) with a swept-source OCT and a noncontact optical biometer at a mean ± SD distance of 3.13 ± 0.88 mm from the limbus. The biometer's graticule was focused and aligned with the anterior scleral reflex, which led to the generation of four prominent A-scan peaks: P1 (anterior bulbar conjunctiva), P2 (anterior episclera), P3 (anterior margin of anterior sclera), and P4 (posterior margin of anterior sclera), which were analyzed and compared with the corresponding OCT landmarks to determine tissue thickness. Results The AST measurements between biometer and OCT correlated for all meridians (r ≥ 0.70, overall r = 0.82; coefficient of variation [CV], 9%-12%; P < 0.01). The mean difference ± SD between two instruments for overall AST measures was 3 ± 2.8 µm (range, -18 to +16 µm; lower limits of agreement, -89 to +83 µm; P = 0.23) across all meridians. The mean ± SE AST with both instruments was found to be thickest at the inferior (562 ± 7 µm and 578 ± 7 µm) and thinnest at the superior (451 ± 7 µm and 433 ± 6 µm) meridian. The biometer demonstrated good intrasession (CV, 8.4%-9.6%) and intersession (CV, 7.9%-13.3%) repeatability for AST measurements across all meridians. Conclusions The noncontact optical biometer, which is typically used to determine axial length, is capable of accurately estimating AST based on OCT landmarks. Translational Relevance The high-resolution optical biometers can demonstrate wider application in the field of myopia research and practice to determine AST.
Collapse
Affiliation(s)
- Satish Kumar Gupta
- Myopia Research Lab, Prof. Brien Holden Eye Research Centre, Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India
| | - Rohit Dhakal
- Myopia Research Lab, Prof. Brien Holden Eye Research Centre, Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India
- The INFOR Myopia Centre, L V Prasad Eye Institute, Hyderabad, India
| | - Pavan Kumar Verkicharla
- Myopia Research Lab, Prof. Brien Holden Eye Research Centre, Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India
- The INFOR Myopia Centre, L V Prasad Eye Institute, Hyderabad, India
| |
Collapse
|
3
|
Lawrenson JG, Gill S, Masuid I, Rashid F. Repeatability and agreement of central corneal thickness measurements with a new handheld non-contact pachymeter. Ophthalmic Physiol Opt 2023; 43:1524-1530. [PMID: 37382205 DOI: 10.1111/opo.13199] [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: 04/19/2023] [Revised: 06/09/2023] [Accepted: 06/16/2023] [Indexed: 06/30/2023]
Abstract
PURPOSE To compare the repeatability of central corneal thickness (CCT) measurements taken with a new handheld pachymeter (Occuity PM1 pachymeter) and to assess its agreement with ultrasound biometry and two commercially available optical biometers in participants with normal eyes. METHODS Three consecutive CCT measurements of the right eye of 105 participants with normal corneas were acquired by the PM1 pachymeter, Lenstar LS 900 and Oculus Pentacam HR in a random order. This was followed by three measurements with a handheld ultrasound pachymeter (UP) (Pachmate 2). Repeatability and the repeatability limit were calculated for each device and Bland-Altman limits of agreement (LoA) were determined for the PM1 pachymeter compared to the other devices. RESULTS The mean CCT (±SD) was 551.04 ± 33.43, 558.62 ± 31.46, 549.41 ± 31.00 and 539.73 ± 29.50 μm for the PM1 pachymeter, UP, Lenstar and Pentacam, respectively. The repeatability limits (expressed as the within subject SD for repeat measurements) were 14.02, 13.68, 4.99 and 9.90 μm, respectively. The closest agreement was between the PM1 and Lenstar (mean difference = -1.63 μm with LoA 10.72 μm below and 13.97 μm above the readings obtained with the Lenstar). The PM1 underestimated CCT compared to UP (mean difference = 7.58 μm, LoA 24.63 μm below and 9.47 μm above UP). The agreement was lowest between the PM1 and Pentacam (mean difference = -11.30 μm, LoA between 4.29 and 26.89 μm). CONCLUSIONS The PM1 pachymeter shows excellent precision for CCT measurements across a range of corneal thicknesses in normal eyes and provides a safe and easy-to-use alternative to ultrasound pachymetry.
Collapse
Affiliation(s)
- John G Lawrenson
- Centre for Applied Vision Research, School of Health and Psychological Sciences, City, University of London, London, UK
| | - Simranjit Gill
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK
| | - Isra Masuid
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK
- Royal Berkshire, NHS Foundation Trust, Reading, UK
| | - Fardip Rashid
- Moorfields Eye Hospital, NHS Foundation Trust, London, UK
| |
Collapse
|
4
|
Towler J, Consejo A, Zhou D, Romano V, Levis H, Boote C, Elsheikh A, Geraghty B, Abass A. Typical localised element-specific finite element anterior eye model. Heliyon 2023; 9:e13944. [PMID: 37101628 PMCID: PMC10123217 DOI: 10.1016/j.heliyon.2023.e13944] [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: 02/21/2022] [Revised: 11/19/2022] [Accepted: 02/15/2023] [Indexed: 03/07/2023] Open
Abstract
Purpose The study presents an averaged anterior eye geometry model combined with a localised material model that is straightforward, appropriate and amenable for implementation in finite element (FE) modelling. Methods Both right and left eye profile data of 118 subjects (63 females and 55 males) aged 22-67 years (38.5 ± 7.6) were used to build an averaged geometry model. Parametric representation of the averaged geometry model was achieved through two polynomials dividing the eye into three smoothly connected volumes. This study utilised the collagen microstructure x-ray data of 6 ex-vivo healthy human eyes, 3 right eyes and 3 left eyes in pairs from 3 donors, 1 male and 2 females aged between 60 and 80 years, to build a localised element-specific material model for the eye. Results Fitting the cornea and the posterior sclera sections to a 5th-order Zernike polynomial resulted in 21 coefficients. The averaged anterior eye geometry model recorded a limbus tangent angle of 37° at a radius of 6.6 mm from the corneal apex. In terms of material models, the difference between the stresses generated in the inflation simulation up to 15 mmHg in the ring-segmented material model and localised element-specific material model were significantly different (p < 0.001) with the ring-segmented material model recording average Von-Mises stress 0.0168 ± 0.0046 MPa and the localised element-specific material model recording average Von-Mises stress 0.0144 ± 0.0025 MPa. Conclusions The study illustrates an averaged geometry model of the anterior human eye that is easy to generate through two parametric equations. This model is combined with a localised material model that can be used either parametrically through a Zernike fitted polynomial or non-parametrically as a function of the azimuth angle and the elevation angle of the eye globe. Both averaged geometry and localised material models were built in a way that makes them easy to implement in FE analysis without additional computation cost compared to the limbal discontinuity so-called idealised eye geometry model or ring-segmented material model.
Collapse
Affiliation(s)
- Joseph Towler
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | | | - Dong Zhou
- Department of Civil Engineering and Industrial Design, School of Engineering, University of Liverpool, Liverpool, UK
| | - Vito Romano
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
- Department of Medical and Surgical Specialities, Radiological Sciences, And Public Health, Ophthalmology Clinic, University of Brescia, Italy
| | - Hannah Levis
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Craig Boote
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Ahmed Elsheikh
- Department of Civil Engineering and Industrial Design, School of Engineering, University of Liverpool, Liverpool, UK
- Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, China
- NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Brendan Geraghty
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Ahmed Abass
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, UK
- Department of Production Engineering and Mechanical Design, Faculty of Engineering, Port Said University, Egypt
| |
Collapse
|
5
|
Ulutas HG, Ozkaya G, Amuk Hamidi N. Comparison of central corneal thickness measured by ultrasound pachymetry, corneal topography, spectral domain- optical coherence tomography, and non-contact specular microscopy. Photodiagnosis Photodyn Ther 2023; 42:103527. [PMID: 36966866 DOI: 10.1016/j.pdpdt.2023.103527] [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: 11/12/2022] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 04/16/2023]
Abstract
BACKGROUND This study aims to investigate the compatibility of central corneal thickness (CCT) measurements obtained with spectral-domain optical coherence tomography (SD-OCT), Scheimpflug-Placido-based corneal topography (CT), non-contact specular microscopy (NCSM), and ultrasonic pachymetry (UP). These four corneal measurement techniques have not been compared in a single study on these many subjects. METHODS CCT was measured in 185 eyes of 185 volunteers with each of the four devices by a single observer. CCTs from Optovue® iVue SD-OCT, Sirius corneal topography, NonconRobo NCSM, and Accutom UP devices were recorded. Compatibility between devices was evaluated with intraclass correlation coefficient (ICC) and Bland-Altman plots. Pairwise comparisons were performed using the Bonferroni test. Measurement differences between devices were analyzed with the Pearson correlation coefficient. RESULTS Of the 185 volunteers, 103 were men, and 82 were women. Their mean age was 48.55 ± 16.6 (18-70) years. Mean CCT values measured by UP, CT, OCT, and NCSM were 546.77 ± 39.2, 535.29 ± 39.2, 526.49 ± 39.05, 505.15 ± 46.1 µm, respectively. Statistically significant differences were found between the mean CCT values obtained from the paired devices (p <0.001). The highest difference between pairs was found between UP and NCSM (43.63 ± 1.8 µm; CI 38.74 to 48.5 µm; p <0.001), while the lowest difference was found between OCT and CT (7.3 ± 1.5 µm; 95%CI 3.1 to 11.6 µm; p <0.001). In pairwise comparisons of four devices, the highest ICC value was between UP and CT (ICC: 0.899, 95%CI 0.759-0.947; p <0.001). CONCLUSION Despite the high correlation between measurements obtained from different methods, notable differences in CCT values exist, rendering devices non-interchangeable. Therefore, alternative brands of the same device may yield different outcomes.
Collapse
Affiliation(s)
- Hafize Gokben Ulutas
- Department of Ophthalmology, University of Health Sciences, Yuksek Ihtisas Training and Research Hospital, Bursa, Türkiye.
| | - Guven Ozkaya
- Department of Biostatistics, Bursa Uludag University, Faculty of Medicine, Bursa, Türkiye
| | - Nagihan Amuk Hamidi
- Department of Ophthalmology, University of Health Sciences, Yuksek Ihtisas Training and Research Hospital, Bursa, Türkiye
| |
Collapse
|
6
|
Romero-Trevejo J, Sánchez-Pérez A, Muñoz-García E, Fernández-Romero L, Jiménez-Navarro M. Comparison of central corneal thickness measurements obtained by OrbscanIIz ® and ultrasound pachymetry: A concordance study in the usual clinical practice. Saudi J Ophthalmol 2023; 37:10-14. [PMID: 36968780 PMCID: PMC10032292 DOI: 10.4103/sjopt.sjopt_82_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/01/2022] [Accepted: 02/01/2023] [Indexed: 03/12/2023] Open
Abstract
PURPOSE The objective of this study was to assess the concordance between the values obtained in measuring central corneal thickness using the OrbscanIIz® and the contact ultrasonic pachymeter available in our public ophthalmology service. METHODS Measurements were taken from 88 eyes of 44 patients using the two instruments. The data obtained were statistically analyzed using version 22 of the IBM SPSS® program. RESULTS The mean of central corneal thickness measurements obtained from OrbscanIIz® was significantly higher than that obtained from ultrasound pachymetry. However, the mean of differences between both instruments was only 7.22 μ, which could be considered a clinically insignificant result when considering the good concordance obtained between both systems. CONCLUSION OrbscanIIz® and ultrasound pachymetry can be interchangeable in the usual public clinical practice when measuring central corneal thickness. This is the first research found in the literature that uses a concordance study to compare the data resulting from central corneal thickness measurements obtained by an OrbscanIIz® and an OcuScan® pachymeter in our environment.
Collapse
|
7
|
Effect of Topical Prostaglandin Analogue Therapy on Central Corneal Thickness: A Systematic Review. J Clin Med 2022; 12:jcm12010044. [PMID: 36614844 PMCID: PMC9821235 DOI: 10.3390/jcm12010044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 12/03/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
To investigate whether prostaglandin analogue (PGA) eyedrops have a significant effect on central corneal thickness (CCT), we conducted a systematic search of literature published from 2000 to 2021. Among the studies conducted on topical PGA therapy in open-angle glaucoma or ocular hypertension patients over 18 years old, prospective studies with CCT change as an outcome were included. A single-arm meta-analysis was conducted to assess the overall effect on CCT, and subgroup analysis according to exposure time of PGA eyedrops was also performed. We counted the number of articles that reported on severe events (CCT reduction of 25 μm or more) and obtained their proportion. The methodological quality was assessed by the McHarm tool. Twenty-two reports of prospective studies were selected. The results of the single-arm meta-analysis showed very high heterogeneity. Still, in subgroup analysis, when PGA was used for more than 6 months, heterogeneity was low, and a significant decrease in CCT was observed. Severe events were reported in two reports and occurred in 3.8% to 14.8% of participants. PGA eyedrop use may cause a clinically significant CCT decrease, requiring CCT follow-up.
Collapse
|
8
|
Yalcın SO, Kaplan AT. Comparison of central corneal thickness measurements with different non-contact devices in healthy children. Photodiagnosis Photodyn Ther 2022; 40:103045. [PMID: 35908681 DOI: 10.1016/j.pdpdt.2022.103045] [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: 05/31/2022] [Revised: 07/17/2022] [Accepted: 07/28/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE To investigate the agreement of the Combined Scheimpflug-Placido Disk System (Sirius), specular microscopy (Tomey EM-4000), non-contact tono-pachymetry (Canon TX-20P), and optical low-coherence reflectometry (Lenstar LS 900) devices in the measurement of central corneal thickness (CCT) in healthy children. METHOD Eighty-three eyes from 83 healthy children were included in the study. The mean age of the children was 11.1 ± 2.8 (range, 7-17) years. CCT was measured using the Sirius topography, Tomey specular microscopy, Canon TX-20P, and Lenstar LS 900 devices. To examine the agreement among these devices, 95% limits of agreement (LoA) and intraclass correlation coefficients (ICC) were determined. RESULTS The mean CCT values obtained using the Sirius topography, Tomey SM, Canon TX-20 P, and Lenstar 900 devices were 555.9 ± 37 µm, 553.5 ± 39 µm, 569.3 ± 33 µm, and 559.7 ± 38 µm, respectively. With the ICC method, the agreement rates were determined as 0.875 between Canon TX-20P and Sirius topography, 0.903 between Canon TX-20P and Lenstar LS 900, 0.842 between Canon TX-20P and Tomey EM-4000, 0.979 between Sirius Topography and Lenstar LS 900, 0.978 between Sirius topography and Tomey EM-4000, and 0.969 between Lenstar LS 900 and Tomey EM-4000. CONCLUSION The devices with the closest results to each other were the Sirius and Tomey EM-4000 devices, with a statistically strong agreement. There was also a strong agreement between Sirius and Lenstar LS 900, although there was a 3.7-unit difference between them. Nevertheless, despite the strong agreements among these devices, because their CCT values varied statistically significantly, these devices should not be used interchangeably in clinical practice.
Collapse
Affiliation(s)
- Sibel Oskan Yalcın
- Department of Ophthalmology, Kartal Dr. Lütfi Kırdar City Hospital, İstanbul, Turkey
| | - Aysin Tuba Kaplan
- Department of Ophthalmology, Kartal Dr. Lütfi Kırdar City Hospital, İstanbul, Turkey.
| |
Collapse
|
9
|
Agreement analysis of Lenstar with other four techniques of biometry before cataract surgery. Int Ophthalmol 2022; 42:3541-3546. [PMID: 35543852 DOI: 10.1007/s10792-022-02352-z] [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: 07/31/2021] [Accepted: 04/18/2022] [Indexed: 10/18/2022]
Abstract
PURPOSE To test whether some biometry measurements provided by the Lenstar LS900 compared well with the AL-Scan, Pentacam rotating Scheimpflug camera, Ultrasound Biomicroscopy (UBM) and Tomey EM-3000. METHODS Two hundred and one patients having routine cataract surgery had standard preoperative assessment. In this clinical study, the axis length (AL) and lens thickness (LT) were taken by Lenstar LS900 and AL-Scan; anterior chamber depth (ACD) was taken by Lenstar LS900, A-Scan, Pentacam and UBM; central corneal thickness (CCT) was taken by Lenstar LS900, Pentacam and Tomey EM-3000. The results were compared using a Wilcoxon-Mann-Whitney U test and Pearson correlation calculations. Agreement was assessed through intraclass correlation coefficients and Bland-Altman plots. RESULTS The highest correlation was found between Lenstar and AL-Scan for AL (r = 0.975; P < 0.001). For LT measurements, the correlation between these two devices was also good (r = 0.699; P < 0.001). Excellent correlations were showed between Lenstar and Pentacam or UBM for ACD (r = 0.948, 0.704, respectively, both P < 0.001), but not between Lenstar and AL-Scan (r = 0.453, P < 0.001). The correlations of CCT between Lenstar and Pentacam or Tomey EM-3000 were both excellent (r = 0.817, 0.882, respectively, both P < 0.001). CONCLUSIONS In phakic eyes of cataract patients, measurements of AL, LT, ACD and CCT from Lenstar LS900 yielded results that correlated very well with other clinical instruments.
Collapse
|
10
|
Montés-Micó R. Evaluation of 6 biometers based on different optical technologies. J Cataract Refract Surg 2022; 48:16-25. [PMID: 34091551 PMCID: PMC8700306 DOI: 10.1097/j.jcrs.0000000000000690] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate repeatability and agreement between various biometric parameters using 6 biometers based on different optical technologies. SETTING University of Valencia, Spain. DESIGN Prospective, comparative case series. METHODS 150 eyes were measured using the Aladdin, AL-Scan, Argos, IOLMaster700, Lenstar LS900, and OA-2000 biometers. Keratometry (K1 and K2), J0 and J45, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL), white to white (WTW), and pupil size (PS) were measured 5 times with each device. Intrasubject SD, coefficient of variability (CoV), coefficient of repeatability, intraclass correlation coefficient, and Bland -Altman graphs were analyzed. RESULTS CoV values were <0.30% for K1, K2, and AL and up to 1.61% for CCT, ACD, LT, and WTW. PS values were higher (from 4.2% to 7.68%). There was statistically significant differences between biometers for all parameters evaluated (P < .001), and these differences varied as a function of the parameter analyzed. The limit of agreement (LoA) width of some comparisons for K1 and the majority for K2 were >0.50 diopter. A similar pattern was found for J0/J45. For CCT, many comparisons showed LoA width values of >25 μm. The LoA width for ACD ranged from 0.366 mm to 0.175 mm and for LT was about 0.2 mm. AL showed a highest LoA width of 0.225 mm. The LoA width for WTW was, in most cases, about ≥0.50 mm. The LoA width for PS ranged from 1.578 mm to 3.541 mm. CONCLUSIONS The 6 biometers provided repeatable measurements for the different parameters analyzed. The LoA obtained for each comparison should be analyzed carefully to consider the interchangeability of these devices.
Collapse
|
11
|
Toptan M, Simsek A. A comparison of central corneal thickness measured using noncontact methods and ultrasonic pachymetry. Niger J Clin Pract 2021; 24:1506-1510. [PMID: 34657017 DOI: 10.4103/njcp.njcp_580_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aim The aim of this study is to compare central corneal thickness (CCT) measurements in healthy eyes using ultrasonic pachymetry (UP) with values obtained using anterior segment spectral domain optical coherence tomography (SD-OCT), the Scheimpflug camera system, and noncontact specular microscopy. Material and Methods One hundred and twenty-five eyes of 117 healthy individuals (56 women, 61 men) were included. All patients underwent consecutive CCT measurement with UP, the Scheimpflug camera, anterior segment SD-OCT, and specular microscopy. The four devices could be read. Measurements from the four devices were classified in pairs and compared using the paired t-test. Relations between the devices were analyzed using the Pearson test. An alpha error level of P < 0.05 was regarded as statistically significant. Results The mean age of the healthy individuals included in the study was 34.75 ± 14.55 years (20-76). Mean CCT values were 541.21 ± 29.24 μm with UP, 539.26 ± 29.27 μm with the Scheimpflug camera system, 532.21 ± 29.53 μm with SD-OCT, and 534.45 ± 29.20 μm with specular microscopy. The differences in measurements at the paired t-test were statistically significant (P < 0.001 for all). However, measurements using the four devices exhibited significant mutual correlation (P < 0.001 for all). Conclusions CCT can be measured using different devices. Noncontact methods have now begun replacing UP, regarded as the gold standard. Although CCT values obtained from different devices were correlated, the difference between these measurements was statistically significant. Therefore, the same device should be used for measurement in the diagnosis and follow-up of diseases such as corneal ectasia and glaucoma where corneal thickness is important.
Collapse
Affiliation(s)
- M Toptan
- Department of Ophthalmology, Harran University, School, of Medicine, Şanlıurfa, Turkey
| | - A Simsek
- Department of Ophthalmology, Harran University, School, of Medicine, Şanlıurfa, Turkey
| |
Collapse
|
12
|
Farvardin M, Shamsi A, Norouzpour A, Jalalpour MH. Central corneal thickness measurements in phakic, pseudophakic, and aphakic children with ultrasound pachymetry and different non-contact devices. Int Ophthalmol 2021; 42:65-72. [PMID: 34370171 DOI: 10.1007/s10792-021-02000-y] [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: 02/20/2021] [Accepted: 07/31/2021] [Indexed: 11/29/2022]
Abstract
AIMS Evidence for choosing a satisfactory device for central corneal thickness (CCT) measurement in children particularly pseudophakic and aphakic ones is insufficient. The aim of this study is to compare four differently measured CCTs obtained using ultrasound pachymetry (UP), Pentacam, partial coherence interferometry (PCI), and specular microscopy (SM) in phakic, pseudophakic, and aphakic children and assess the agreement between the six pairs of the methods. METHODS Children with history of cataract surgery at age six or younger and phakic children were recruited into this study. CCT was measured using UP (Optikon 2000, Rome, Italy), Pentacam (Oculus Inc, Wetzlar, Germany), PCI (IOLMaster 700, Carl Zeiss Meditec AG, Jena, Germany), and SM (Topcon SP-3000P; Topcon Corporation, Japan). RESULTS One-hundred two eyes (53 phakic, 29 pseudophakic, and 20 aphakic eyes) were included. The mean ages (± SD) of phakic, pseudophakic, and aphakic cases were 9.75 (± 3.3), 9.9 (± 2.3), and 8.2 (± 2.8) years, respectively. The mean CCTs (± SE) for phakic children using Pentacam, PCI, UP, and SM were 549.7 (± 5.0), 546.5 (± 4.5), 565.9 (± 5.5), and 506.2 (± 4.4) μm, respectively, for pseudophakic cases were 570.1 (± 6.4), 565.0 (± 6.1), 571.9 (± 6.3), and 524.3 (± 6.3) μm, respectively, and for aphakic participants were 635.3 (± 14.2), 635.4 (± 14.5), 649.0 (± 13.5), and 589.1 (± 13.3) μm, respectively. CONCLUSION Compared to Pentacam and PCI, SM underestimated CCT particularly in phakic and pseudophakic children, whereas UP slightly overestimated CCT especially in phakic and aphakic children. Furthermore, Pentacam and PCI had the closest agreement. By contrast, SM had the poorest agreement with the other three methods.
Collapse
Affiliation(s)
- Majid Farvardin
- Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Anis Shamsi
- Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Norouzpour
- Poostchi Eye Clinic, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Mohammad-Hasan Jalalpour
- Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| |
Collapse
|
13
|
Üçer MB, Bozkurt E. Comparison of central corneal thickness measurements with three different optical devices. Ther Adv Ophthalmol 2021; 13:2515841421995633. [PMID: 33748670 PMCID: PMC7905717 DOI: 10.1177/2515841421995633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/27/2021] [Indexed: 11/30/2022] Open
Abstract
Purpose: The purpose of this study was to compare and evaluate the agreement of central corneal thickness (CCT) values obtained with three different devices working according to optical principle in healthy eyes. Methods: 60 eyes of 60 individuals (30 men and 30 women) were enrolled in this study. CCT measurements performed with Scheimpflug–Placido topographer (Sirius), spectral-domain optical coherence tomography (RTVue) with an anterior segment module, and optical biometer (AL-Scan) were compared. Bland–Altman analysis was used to demonstrate agreement between methods. Results: The mean age was 30.07 ± 7.313 years (range, 18–47 years). The mean CCT values obtained by RTVue, Sirius, and AL-Scan were 518.25 ± 36.38 µm, 526.08 ± 36.33 µm, and 513.50 ± 39.09 µm, respectively. The mean differences in CCT were 7.83 ± 14.15 µm between Sirius and RTVue, 12.58 ± 11.87 µm between Sirius and AL-Scan, and 4.75 ± 4.50 µm between RTVue and AL-Scan. The mean CCT was statistically different among the three groups (p < 0.05). All three modalities of CCT measurements correlated closely with each other, with Pearson’s correlation coefficients ranging from 0.924 to 0.961. The 95% limits of agreement were −19.90 to 35.56 µm between Sirius and RTVue, −10.69 to 35.85 µm between Sirius and AL-Scan, and −4.07 to 13.58 µm between RTVue and AL-Scan. Conclusion: Different results could be obtained through different noncontact devices in CCT measurements. Although the measurement values obtained by these devices show a high level of correlation, it would be a more correct approach to not use them directly interchangeably in clinical practice. Evaluation and follow-up of CCT should be performed using the same device.
Collapse
Affiliation(s)
| | - Erdinç Bozkurt
- Department of Ophthalmology, Faculty of Medicine, Kafkas University, Kars, Turkey
| |
Collapse
|
14
|
Jin Y, McAlinden C, Sun Y, Wen D, Wang Y, Yu J, Feng K, Song B, Wang Q, Chen S, Huang J. Sirius Scheimpflug-Placido versus ultrasound pachymetry for central corneal thickness: meta-analysis. EYE AND VISION 2021; 8:5. [PMID: 33602345 PMCID: PMC7891160 DOI: 10.1186/s40662-021-00227-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 01/13/2021] [Indexed: 11/26/2022]
Abstract
Background To compare the difference in central corneal thickness (CCT) measurements in normal eyes between a rotating Scheimpflug camera combined with a Placido-disk corneal topographer (Sirius, CSO, Italy) and ultrasound pachymetry (USP). Methods A systematic literature search was conducted for relevant studies published on PubMed, Medline, EMBASE, and the Cochrane Library and ClinicalTrials.gov from inception to August 1st, 2019. Primary outcome measures were CCT measurements between Sirius and USP. A random effects model was used to pool CCT measurements. Results A total of twelve studies involving 862 eyes were included in this meta-analysis. The meta-analysis found CCT measurements between Sirius and USP to be statistically significantly different (P < 0.0001). The mean difference between Sirius and USP was −11.26 μm with a 95% confidence interval (CI) (−16.92 μm, −5.60 μm). The heterogeneity was I2 = 60% (P = 0.004). Conclusion CCT measurements with the Sirius Scheimpflug-Placido topographer were statistically significantly lower than USP. However, it may be argued that the mean difference of 11.26 μm is not a clinically significant difference.
Collapse
Affiliation(s)
- Yili Jin
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Colm McAlinden
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Department of Ophthalmology, Singleton Hospital, Swansea Bay University Health Board, Swansea, UK
| | - Yong Sun
- Shenzhen Hospital of Integrated Traditional and Western Medicine, Shenzhen, China
| | - Daizong Wen
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yiran Wang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jinjin Yu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ke Feng
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Benhao Song
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qinmei Wang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China
| | - Shihao Chen
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China. .,Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China. .,Eye Hospital of Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, 325027, Zhejiang, China.
| | - Jinhai Huang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China. .,Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang, China. .,Eye Hospital of Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, 325027, Zhejiang, China.
| |
Collapse
|
15
|
Gharieb HM, Shalaby HS, Othman IS. Repeatability and Interchangeability of Topometric, Anterior Chamber and Corneal Wavefront Data Between Two Scheimpflug Camera Devices. Clin Ophthalmol 2020; 14:3801-3810. [PMID: 33177806 PMCID: PMC7652572 DOI: 10.2147/opth.s274303] [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: 07/28/2020] [Accepted: 10/16/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose This study aims to assess the intra-operator repeatability and correlation of the Pentacam HR (device 1) and Sirius (device 2) in measuring anterior segment parameters and to evaluate the agreement of their readings and therefore their interchangeability in a clinical setting. Methods This is a prospective non-randomized study was conducted on the right eyes of 102 subjects coming to Eye World Hospital, Giza, Egypt. With each machine, four scans were taken by a single examiner. Each device was used to measure keratometric indices, corneal thickness, anterior chamber depth, anterior chamber angle, corneal diameter and corneal optical aberrations. Results Both devices show high repeatability for corneal thickness, corneal diameter, anterior chamber depth and keratometric indices (except for maximum keratometry, where device 1 shows high repeatability and device 2 shows low repeatability). On the other hand, both devices show poor repeatability for anterior chamber angle, Q-values, root mean square, spherical, coma and trefoil aberrations. The readings of the two devices are strongly correlated as regards only keratometric indices, corneal thickness and anterior chamber depth. In addition, the readings of the devices are in good agreement as regards only keratometric indices (except maximum keratometry), corneal thickness, anterior chamber depth, anterior chamber angle, root mean square, spherical and trefoil aberrations. Conclusion Both devices showed variable intra-observer repeatability, with the device 1 showing slightly higher repeatability. Despite the similarity between some of the readings of the two devices, caution is advised before considering them interchangeable. We therefore do not recommend using them in alternation in refractive surgery.
Collapse
Affiliation(s)
- Hesham Mohamed Gharieb
- Faculty of Medicine, Ain Shams University, Cairo, Egypt.,Research and Development, Eye World Hospital, Giza, Egypt
| | - Hisham Samy Shalaby
- Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Ihab Saad Othman
- Eye World Hospital, Giza, Egypt.,Faculty of Medicine, Cairo University, Giza, Egypt
| |
Collapse
|
16
|
Zakrzewska A, Wiącek MP, Machalińska A. Impact of corneal parameters on intraocular pressure measurements in different tonometry methods. Int J Ophthalmol 2019; 12:1853-1858. [PMID: 31850168 DOI: 10.18240/ijo.2019.12.06] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 10/29/2019] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the impact of central corneal thickness (CCT) and corneal curvature on intraocular pressure (IOP) measurements performed by three different tonometers. METHODS IOP in 132 healthy eyes of 66 participants was measured using three different tonometry techniques: Goldmann applanation tonometer (GAT), Pascal dynamic contour tonometer (DCT), and ICare rebound tonometer (RT). CCT and corneal curvature were assessed. RESULTS In healthy eyes, DCT presents significantly higher values of IOP than GAT (17.34±3.69 and 15.27±4.06 mm Hg, P<0.0001). RT measurements are significantly lower than GAT (13.56±4.33 mm Hg, P<0.0001). Compared with GAT, DCT presented on average 2.51 mm Hg higher values in eyes with CCT<600 µm and 0.99 mm Hg higher results in eyes with CCT≥600 µm. The RT results were lower on average by 1.61 and 1.95 mm Hg than those obtained by GAT, respectively. Positive correlations between CCT in eyes with CCT<600 µm were detected for all IOP measurement techniques, whereas a similar relationship was not observed in eyes with thicker corneas. A correlation between IOP values and keratometry in the group with CCT<600 µm was not detected with any of the tonometry methods. In thicker corneas, a positive correlation was found for GAT and mean keratometry values (R=0.369, P=0.005). CONCLUSION The same method should always be chosen for routine IOP control, and measurements obtained by different methods cannot be compared. All analysed tonometry methods are dependent on CCT; thus, CCT should be taken into consideration for both diagnostics and monitoring.
Collapse
Affiliation(s)
- Aleksandra Zakrzewska
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
| | - Marta P Wiącek
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
| | - Anna Machalińska
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
| |
Collapse
|
17
|
Pellucid marginal degeneration: Detection, discrimination from other corneal ectatic disorders and progression. Cont Lens Anterior Eye 2019; 42:341-349. [DOI: 10.1016/j.clae.2018.11.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/07/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023]
|