scholarly journals Comparison of central corneal thickness measurements with three different optical devices

2021 ◽  
Vol 13 ◽  
pp. 251584142199563
Author(s):  
Mehmet Barış Üçer ◽  
Erdinç Bozkurt
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Correlation Coefficients ◽  
Limits Of Agreement ◽  
The Mean ◽  
Mean Differences ◽  
High Level ◽  
Thickness Measurements

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.

scholarly journals Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Jinhai Huang ◽  
Weicong Lu ◽  
Giacomo Savini ◽  
Hao Chen ◽  
Chengfang Wang ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Normal Subjects ◽  
Optical Coherence ◽  
Limits Of Agreement ◽  
Mean Values ◽  
The Mean

Purpose.To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan) and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA) for measuring central corneal thickness (CCT), anterior chamber depth (ACD), and aqueous depth (AD).Methods.Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using pairedt-tests, Bland-Altman plots, and 95% limits of agreement (LoA).Results.The mean CCT, ACD, and AD measured by AL-Scan were538.59±27.37 μm,3.70±0.30 mm, and3.16±0.30 mm, respectively. The mean values obtained by the Visante OCT were536.14±26.61 μm for CCT,3.71±0.29 mm for ACD, and3.17±0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference =2.45±6.07 μm,P<0.05). The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively.Conclusions.Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic.

scholarly journals Reproducibility of Central Corneal Thickness Measurements in Normal Eyes Using the Zeiss Cirrus 5000 HD-OCT and Pentacam HR

2018 ◽  
Vol 12 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Elmira Baghdasaryan ◽  
Xiwen Huang ◽  
Kenneth M. Marion ◽  
Tudor C. Tepelus ◽  
Homayoun Bagherinia ◽  
...  
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Test Analysis ◽  
Cirrus Oct ◽  
Repeatability And Reproducibility ◽  
The Mean ◽  
Highly Correlated ◽  
Thickness Measurements ◽  
Intra Class Correlation Coefficient

Objectives:To determine the repeatability and reproducibility of Central Corneal Thickness (CCT) measurements using two different anterior segment imaging modalities, including those obtained with the new anterior segment lens attachments for the Cirrus 5000 HD-OCT.Methods:A total of 32 eyes from 16 normal volunteers (8 male, 8 female) were enrolled in this prospective study. CCT was measured by the same examiner using the Cirrus 5000 HD-OCT and Pentacam HR. The results of CCT obtained by each method were averaged and compared using t-test analysis. The agreement between the measurement methods was evaluated. Coefficient of Repeatability (CoR) and Intra-Class Correlation Coefficient (ICC) were computed.Results:The mean measurements taken with the Cirrus OCT anterior chamber lens (CCTAC), HD cornea lens (CCTHDC) and pachymetry scans (CCTPach) were 545.35 ± 31.02, 537.87 ± 26.82, and 532.04 ± 29.82 µm, respectively. The mean CCT obtained with the Pentacam (CCTPent) was 545.51 ± 30.71 µm. CCTPentwere significantly higher than CCTHDCand CCTPach(p< 0.0001). In contrast, the CCTPentand CCTACwere similar (p=0.87). CCT, as evaluated by the two different instruments, showed excellent correlation (r> 0.98,p< 0.0001) with an ICC > 0.99 (95% CI, 0.97 – 0.99). CoR was the highest for CCTPach(3.7 ± 1.4, 95% CI (3.0- 4.6)).Conclusion:CCT measurements from the Cirrus OCT using the new anterior segment lens attachments and the Pentacam HR are highly correlated. This should allow the use of a standardized correction factor if necessary to inter-relate the measurements between the two devices.

scholarly journals Correlation between Central Corneal Thickness and Degree of Myopia among Malaysian Patients Undergoing Laser Keratorefractive Surgery

2020 ◽  
pp. 52-58
Author(s):  
Sagili Chandrasekhara Reddy ◽  
Mohd Mansor Shariff ◽  
Aina Malindri Dasrilsyah
Keyword(s):  
Optical Coherence Tomography ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Military Hospital ◽  
Moderate Degree ◽  
Optical Coherence ◽  
Corneal Refractive Surgery ◽  
The Mean

Purpose: To determine the central corneal thickness in myopic adult patients scheduled for laser corneal refractive surgery and to explore its correlation with degree of refractive error. Materials and Methods: The case records of 130 myopic patients who underwent laser corneal refractive surgery in a military hospital over a period of two years were reviewed to determine the central corneal thickness. All patients had 6/6 vision with best correction, and did not have any other anterior segment or fundus diseases in both eyes. The central corneal thickness was measured with Visante Carl Zeiss anterior segment optical coherence tomography instrument.                                                                                                                        Results: Out of 130 patients, males were more (73, 56.2%); mean age of patients was 33.8 years (range 18-60 years) and majority were Malays (110, 84.6%).  The spherical power of myopia ranged from – 0.5 to – 10.00 D, and the cylindrical power ranged from – 0.25 to – 3.25 D. The mean central corneal thickness of both eyes was 528.2 µm (range 331- 615 µm); in the mild degree of myopia (- 0.50 to - 2.00 D) 527.9 µm, moderate degree (- 2.25 to -5.00 D) 529.4 µm, and high degree (-5.25 to -11.00 D) 523.9 µm. Conclusion: The anterior segment optical coherence tomography provides noncontact, rapid, pachymetry mapping of the corneal thickness. In Malaysian patients, the mean central corneal thickness of both eyes in myopia was 528.1 µm (range 331- 615 µm). There was no correlation between the mean central corneal thickness and degree of myopia, different genders, age groups, ethnic groups and two eyes.

Self-measurement with Icare HOME tonometer, patients’ feasibility and acceptability

2019 ◽  
Vol 30 (2) ◽  
pp. 258-263 ◽  
Author(s):  
Barbara Cvenkel ◽  
Makedonka Atanasovska Velkovska ◽  
Vesna Dimovska Jordanova
Keyword(s):  
Intraocular Pressure ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Pressure Data ◽  
Limits Of Agreement ◽  
Goldmann Applanation Tonometer ◽  
Applanation Tonometer ◽  
Perception Of Self ◽  
The Mean

Purpose: To evaluate and compare the accuracy of self-measurement of intraocular pressure using Icare Home rebound tonometer with Goldmann applanation tonometer and assess acceptability of self-tonometry in patients with glaucoma and ocular hypertension. Methods: In the study, 117 subjects were trained to use Icare Home for self-measurement. Icare Home tonometer readings were compared with Goldmann applanation tonometer, including one eye per patient. Agreement between the two methods of measurement was evaluated by Bland and Altmann analysis. Questionnaire was used to evaluate patients’ perception of self-tonometry. Results: One hundred and three out of 117 patients (88%) were able to measure their own intraocular pressure and 96 (82%) fulfilled the requirements for certification. The mean (SD) difference Goldmann applanation tonometer minus Icare Home was 1.2 (2.4) mmHg (95% limits of agreement, –3.4 to 5.9 mmHg). The magnitude of bias between the two methods depended on central corneal thickness, with greater bias at central corneal thickness <500 µm. In 65 out of 96 subjects (67.7%), Icare Home results were within 2 mmHg of the Goldmann applanation tonometer. Seventy-three out of 93 (78.5%) felt that self-tonometry was easy to use and 75 patients (80.6%) responded that they would use the device at home. Conclusion: Icare Home tonometry tends to slightly underestimate intraocular pressure compared to Goldmann applanation tonometer. Most patients were able to perform self-tonometry and found it acceptable for home use. Measurements using rebound self-tonometry could improve the quality of intraocular pressure data and optimize treatment regimen.

scholarly journals Measurements of Corneal Thickness in Eyes with Pseudoexfoliation Syndrome: Comparative Study of Different Image Processing Protocols

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Katarzyna Krysik ◽  
Dariusz Dobrowolski ◽  
Katarzyna Polanowska ◽  
Anita Lyssek-Boron ◽  
Edward A. Wylegala
Keyword(s):  
Time Domain ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Imaging Systems ◽  
Pressure Measurements ◽  
Swept Source ◽  
Swept Source Oct ◽  
The Mean ◽  
Thickness Measurements ◽  
Cataract Patients

Purpose. Comparative analysis of central and peripheral corneal thickness in PEX patients using three different imaging systems: Pentacam-Scheimpflug device, time-domain optical coherence tomography (OCT) Visante, and swept-source OCT Casia. Materials and Methods. 128 eyes of 80 patients with diagnosed PEX were examined and compared with 112 normal, non-PEX eyes of 72 cataract patients. The study parameters included 5 measured zones: central and 4 peripheral (superior, inferior, nasal, and temporal). Results. The mean CCT in eyes with PEX syndrome measured with all three instruments was thicker than that in normal eyes. Corneal thickness measurements in the PEX group were statistically significantly different between Pentacam and OCT Casia: central corneal thickness (p=0.04), inferior corneal zone (p=0.01), and nasal and temporal corneal zones (p<0.01). Between Pentacam and OCT Visante inferior, nasal and temporal corneal zones were statistically significantly different (p<0.01). Between OCT Casia and OCT Visante, there were no statistically significant differences in measured parameters values. Conclusion. The central corneal thickness in eyes with PEX syndrome measured with three different independent methods is higher than that in the non-PEX group, and despite variable peripheral corneal thickness, this one parameter is still crucial in intraocular pressure measurements.

Comparison of Central Corneal Thickness Measurements Using Ultrasonic Pachymetry, Anterior Segment OCT and Noncontact Specular Microscopy

2017 ◽  
Vol 26 (10) ◽  
pp. 860-865 ◽  
Author(s):  
Riccardo Scotto ◽  
Alessandro Bagnis ◽  
Marina Papadia ◽  
Carlo Alberto Cutolo ◽  
Domenico Risso ◽  
...  
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Specular Microscopy ◽  
Anterior Segment Oct ◽  
Thickness Measurements ◽  
Ultrasonic Pachymetry

scholarly journals Repeatability of central and peripheral corneal thickness measurements with the iVue100 optical coherence tomographer

2016 ◽  
Vol 75 (1) ◽  
Author(s):  
Nishanee Rampersad ◽  
Rekha Hansraj
Keyword(s):  
Linear Regression ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Optical Coherence ◽  
Contact Lens Wear ◽  
Mean Differences ◽  
The University ◽  
Thickness Measurements ◽  
Sd Oct

Background: Accurate assessment of corneal thickness is essential in corneal refractive surgery, contact lens wear and corneal pathology.Aim: To assess the repeatability (intra-observer, inter-observer and inter-session) of central (0 mm – 2 mm), mid-peripheral (2 mm – 5 mm) and peripheral (5 mm – 6 mm) corneal thickness measurements using the iVue 100 spectral domain optical coherence tomographer (SD-OCT).Setting: Optometry Eye Clinic at the University of KwaZulu-Natal (UKZN).Methods: Corneal thickness measurements were taken on 50 healthy participants by two observers independently. A second set of readings was taken by one observer on another session. Repeatability was assessed using Bland–Altman analysis, the intraclass correlation coefficient, coefficient of variation and one-way analysis of variance (ANOVA) analysis.Results: For all corneal regions, the intraclass correlation coefficients for observer one ranged from 0.942 to 0.999 and that for observer two ranged from 0.946 to 0.999, indicating good intra-observer repeatability. Using linear regression, the corneal thickness measurements were found to be comparable (within 1 µm of each other) in all regions with the exception of the nasal and temporal mid-periphery and periphery. The inter-session repeatability was based on the measurements of observer one only with the mean differences ranging from 0.02 µm to 0.63 µm. Linear regression revealed no significant differences between session 1 and session 2 (p > 0.05) except for the measurement of minimum corneal thickness.Conclusion: This study found evidence of good intra-observer, inter-observer and intersession repeatability of central, mid-peripheral and peripheral corneal measurements with the iVue 100 SD-OCT.

scholarly journals Role of anterior segment optical coherence tomography in the evaluation of microbial keratitis

2021 ◽  
Vol 7 (3) ◽  
pp. 548-553
Author(s):  
Isha Chaturvedi ◽  
Kamaljeet Singh ◽  
Jagriti Rana ◽  
Kshama Dwivedi ◽  
Reena Sachan
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Morphological Characteristics ◽  
Objective Evaluation ◽  
Response To Treatment ◽  
Optical Coherence ◽  
Microbial Keratitis ◽  
The Mean

Anterior segment optical coherence tomography (AS-OCT) is a newer technology that provides two-dimensional images of corneal infiltration. This study was undertaken to assess whether AS-OCT can aid objective evaluation and response to treatment in resolving microbial keratitis. This prospective study was performed on 17 patients of who underwent slit lamp and AS-OCT examination at presentation and follow up on days 3, 7, 14, 28 and 6 weeks. A standardized scanning protocol was used to measure the corneal thickness (CT) and infiltrate thickness (IT) using the caliper tool of a commercially available AS-OCT device. The mean CT in the infiltrated area and mean IT, both were thickest at presentation (710.88 um and 288.76 um respectively). The mean CT decreased to 665.12 µm, 650.24 µm, 584.35 µm, 549 µm, 507.47 µm on days 3, 7, 14, 28 and 6 weeks respectively. Similarly, the mean IT decreased to 287.24 µm, 244.41 µm, 197 µm, 174.59 µm and 154.82 µm. Paired t- test was used to calculate the statistical change in CT and IT, which was significant (p&#60;0.0001) at 6 weeks, at the rate of 0.67% and 1.01% per day. AS-OCT can show morphological characteristics of microbial keratitis and give quantitative assessment at every follow up.

Inter-Observer Reproducibility of Axial Ocular Measurements with Non-contact HAAG-STRAIT Biometer

2021 ◽  
Vol 37 (3) ◽  
Author(s):  
Muhammad Suhail Sarwar ◽  
Sehrish Shahid ◽  
Muhammad Arslan Ashraf ◽  
Shaista Kanwal
Keyword(s):  
Data Analysis ◽  
Anterior Chamber ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Excellent Correlation ◽  
Interclass Correlation ◽  
The Mean

Purpose:  To check inter observer reproducibility of axial ocular measurements i.e. central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AD), lens thickness (LT), anterior segment lens (ASL), vitreous length (VL) and axial length (AL) with non-contact HAAG-STRAIT biometer. Study Design:  Comparative Reproducibility Analysis. Place and Duration of Study:  College of ophthalmology and allied vision sciences (COAVS), Mayo Hospital, Lahore. Methods:  This study included 66 healthy students (132 eyes). Data was collected through self-designed proforma by 2 operators independently. SPSS 21 was used for data analysis. Interclass correlation was applied for agreement between the two readings. Interclass coefficient (ICC) value greater than 0.7 was considered as excellent correlation. Results:  The mean CCT, AD, ACD, LT, ASL, VL, and AL were 526.47 ± 35.72 µm and 526.47 ± 36.06 µm (ICC = 0.92); 2.93 ± 0.29 mm and 2.93 ± 0.29 mm (ICC = 0.81); 3.45 ± 0.30 mm and 3.46 ± 0.30 mm (ICC = 0.79); 3.58 ± 0.28 mm and 3.56 ± 0.22 mm (ICC = 0.76); 7.03 ± 0.30 mm and 7.02 ± 0.27 mm (ICC = 0.80); 16.56 ± 0.85 mm and 16.62 ± 0.81 mm (ICC = 0.72); and 23.59 ± 0.85 mm and 23.64 ± 0.87 mm (ICC: 0.76) of observer 1 and 2, respectively. Conclusion:  Non-contact Biometer (HAAG-STRAIT) has high inter-observer reproducibility with strong interclass coefficient of greater than 0.72. Key Words:  Biometry, Axial Length, Central Corneal Thickness, Anterior Chamber Depth.

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