Repeatability and Agreement of Orbscan II, Pentacam HR, and Galilei Tomography Systems in Corneas With Keratoconus

Meyer, Jay J.; Gokul, Akilesh; Vellara, Hans; Prime, Zak; McGhee, Charles N J

doi:10.1016/j.ajo.2016.12.003

Cited by 87 publications

(61 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Galilei and Pentacam in keratoconic eyes and observed that Orbscan II has the least repeatable measurements. Furthermore there was no significant difference between Pentacam and Galilei [11]. Another study that showed no agreement between corneal diameters measured by Galilei.…”

Section: Discussionmentioning

confidence: 90%

“…we compared the repeatability and interoperator reproducibility of a new corneal topographer module of Revo NX SD-OCT with Galilei G6 Schimpflug camera and Casia 2 SS-OCT in normal eyes. As it was concluded in many previous studies the measurements from two keratometric systems cannot be used interchangeably [3,[10][11][12] There are two types of devices capable of measuring anterior and posterior keratometry: OCT based systems and Scheimpflug camera. Some OCT systems use swept-source technology featuring lower resolution but faster acquisition rate [13].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Reproducibility, and repeatability of corneal topography measured by Revo NX, Galilei G6 and Casia 2 in normal eyes

et al. 2020

View full text Add to dashboard Cite

PurposeTo test the repeatability and reproducibility of the topography module in posterior segment spectral domain optical coherence tomography with Revo NX (new device) and to compare keratometry values obtained by a Scheimpflug tomography (Galilei G6) and a swept source OCT (Casia 2). MethodsIn this prospective study, healthy subjects with nonoperated eyes had their central corneal thickness (CCT), anterior and posterior K1/K2 corneal power measured with the new device. Two operators made 6 measurements on the new device to check intraobserver repeatability and reproducibility, and measurement on Casia 2 and Galilei G6. Bland-Altman plots were used to assess the agreement between the devices for each analyzed variable. Results94 eyes (94 patients) were studied. All devices produced significantly different mean CCT, the highest for Galilei 569.13±37.58 μm followed by Casia 545.00 ±36.15 μm and Revo 537.39±35.92 μm. The mean anterior K1 was 43.21 ± 1.37 for Casia 2 43.21 ± 1.55 for Revo NX and 43.19 ± 1.39 for Galilei G6, and the differences were insignificant p = 0.617. The posterior K1 for Revo NX was -5.77 ± 0.25 whereas for Casia 2 it was -5.98±0.22 and for Galilei G6-6.09±0.28 D p< 0.0001. The Revo NX showed intraclass correlation coefficient ranging from 0.975 for the posterior K2 surface, and 0.994 for anterior K1 and 0.998 for CCT. ConclusionsRevo NX is independent of the user and offers a high level of repeatability for the anterior and posterior cornea. The wide range of differences between the devices suggests they should not be used interchangeably.

show abstract

Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Reproducibility, and repeatability of corneal topography measured by Revo NX, Galilei G6 and Casia 2 in normal eyes

et al. 2020

View full text Add to dashboard Cite

show abstract

“…[4] At present, various methods are used for the CCT measurement, such as ultrasound pachymetry (USP), Scheimflug photography, optical coherence tomography and so on. [5][6][7][8][9] Most often, USP is regarded as the gold-standard technique for measuring CCT. [10][11][12] Many studies have evaluated the precision (repeatability and reproducibility) and agreement of CCT measurements among the abovementioned devices.…”

Section: Introductionmentioning

confidence: 99%

“…[10][11][12] Many studies have evaluated the precision (repeatability and reproducibility) and agreement of CCT measurements among the abovementioned devices. [7,8,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] The results, however, have not always been consistent.…”

Section: Introductionmentioning

confidence: 99%

Precision and Agreement of Central Corneal Thickness Measured with E-pach, A-scan, Corvis ST and Pentacam

Liu

Wang

et al. 2019

Preprint

View full text Add to dashboard Cite

Purpose To assess the precision (repeatability and reproducibility) and agreement of central corneal thickness (CCT) measurements by E-pach, Pentacam, Corvis ST and A-scan devices in healthy eyes. Methods Instrument diagnostic test study. A total of 100 patients were enrolled to measure right-eye CCT by E-pach, Pentacam, Corvis ST, and A-scan devices. To assess repeatability and reproducibility, the test-retest repeatability (TRT) and intraclass correlation coefficient (ICC) were calculated. The agreement among the four devices was evaluated with Bland-Altman plots. Results The E-pach showed repeatability (ICC=0.9981), interobserver reproducibility (ICC=0.9971) and intersession reproducibility (ICC=0.9825); the Pentacam, Corvis ST and A-scan also showed similar repeatability (all ICC≥0.9679), interobserver reproducibility (all ICC≥0.9730) and intersession reproducibility (all ICC≥0.9647). However, the E-pach yielded CCT values that were obviously lower than those of the A-scan and Pentacam (P<0.001) but higher than those of the Corvis ST (P<0.001). The 95% limits of agreement (LoA) in the Bland-Altman plots were 44.5 µm (E-pach vs. A-scan), 34.9 µm (E-pach vs. Corvis CT) and 32.5 µm (E-pach vs. Pentacam). Conclusions The E-pach is a portable, reliable and inexpensive pachymeter. However, the CCT values obtained from the E-pach are not interchangeable with those from Pentacam, Corvis ST and A-scan devices.

show abstract

“…Several studies have demonstrated better measurement precision in healthy eyes 10,11 than keratoconic eyes 12–14 , for various clinical parameters and different imaging devices. Previously reported repeatability and reproducibilty data of keratoconic eyes have been inconsistent and vary considerably among different studies and devices.…”

Section: Introductionmentioning

confidence: 99%

Improving precision for detecting change in the shape of the cornea in patients with keratoconus

Brunner

Czanner

Vinciguerra

et al. 2018

Sci Rep

View full text Add to dashboard Cite

To investigate a method for precision analysis to discriminate true corneal change from measurement imprecision in keratoconus (KC). Thirty patients with KC and 30 healthy controls were included. Coefficients of repeatability and limits of agreement (LOA) were compared using multiple measurements for inter-observer and inter-device agreement with the Pentacam HR, Orbscan IIz, and Tomey Casia SS-1000. Correlation of repeated measurements was evaluated using a linear mixed effect model (also called random effect model). A formula was derived for the theoretical expected change in precision and compared with measured change. Correlation between measurements from the same eye was small (R = 0.13). The 99.73% LOA (3 SD) of the mean of three measurements, provided better precision than 95% LOA (2 SD) of single cut-off values as expected from statistical theory for uncorrelated measurements for evidence of a significant change in corneal shape in patients with keratoconus. This enabled the determination of cut-off values for the detection of true change in corneal shape. The mean of three repeated measurements will provide better precision when there is minimal correlation. Three (rather than two) standard deviations provides a precise estimate of the LOA within or between observers and can be used as a reliable measure for identifying stage-independent corneal shape changes (progression) in keratoconus.

show abstract

Repeatability and Agreement of Orbscan II, Pentacam HR, and Galilei Tomography Systems in Corneas With Keratoconus

Cited by 87 publications

References 27 publications

Reproducibility, and repeatability of corneal topography measured by Revo NX, Galilei G6 and Casia 2 in normal eyes

Reproducibility, and repeatability of corneal topography measured by Revo NX, Galilei G6 and Casia 2 in normal eyes

Precision and Agreement of Central Corneal Thickness Measured with E-pach, A-scan, Corvis ST and Pentacam

Improving precision for detecting change in the shape of the cornea in patients with keratoconus

Contact Info

Product

Resources

About