Automated keratometry in routine cataract surgery: Comparison of Scheimpflug and conventional values

Symes, Richard; Ursell, Paul G.

doi:10.1016/j.jcrs.2010.08.050

Cited by 46 publications

(26 citation statements)

References 20 publications

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“…Many studies 4,7,9,[24][25][26] have compared astigmatism magnitudes (K values) without taking the astigmatism meridian into account and in general found good agreement of measurements obtained by automated keratometry, manual keratometry, corneal topography, and Scheimpflug imaging. However, some studies found significant differences between devices.…”

Section: Discussionmentioning

confidence: 96%

“…Several studies have been performed to compare corneal astigmatism measurements obtained with different keratometers, [3][4][5] Placido-disk videokeratoscopes, [6][7][8] and Scheimpflug imagers. 6,8,9 However, in general, these studies compared astigmatism magnitudes only, with no regard to the astigmatism meridian. Because astigmatism is a vector with a magnitude and a direction, vector analysis must be used to compare astigmatism data.…”

mentioning

confidence: 99%

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Comparability and repeatability of corneal astigmatism measurements using different measurement technologies

Visser

Berendschot

Verbakel

et al. 2012

Journal of Cataract and Refractive Surgery

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Section: Discussionmentioning

confidence: 96%

mentioning

confidence: 99%

Comparability and repeatability of corneal astigmatism measurements using different measurement technologies

Visser

Berendschot

Verbakel

et al. 2012

Journal of Cataract and Refractive Surgery

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“…Another group recently found a difference of -0.033 mm (equal to 0.19 D), also regarding the steep meridian [8]. Studies based on the former version of Pentacam or Pentacam HR also indicated differences in keratometric measurements [19][20][21][22][23][24]. Karunaratne found statistically significant differences between the mean keratometric values of the IOL Master and Pentacam equivalent keratometry readings at 2-, 3-and 4.5-mm zone measurements.…”

Section: Discussionmentioning

confidence: 99%

Comparison of anterior segment parameters and axial length measurements performed on a Scheimpflug device with biometry function and a reference optical biometer

Muzyka−Woźniak¹,

Oleszko

2018

Int Ophthalmol

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Purpose To compare measurements of axial length (AL), corneal curvature (K), anterior chamber depth (ACD) and white-to-white (WTW) distance on a new device combining Scheimpflug camera and partial coherence interferometry (Pentacam AXL) with a reference optical biometer (IOL Master 500). To evaluate differences between IOL power calculations based on the two biometers. Methods Ninety-seven eyes of 97 consecutive cataract or refractive lens exchange patients were examined preoperatively on IOL Master 500 and Pentacam AXL units. Comparisons between two devices were performed for AL, K, ACD and WTW. Intraocular lens (IOL) power targeting emmetropia was calculated with SRK/T and Haigis formulas on both devices and compared. Results There were statistically significant differences between two devices for all measured parameters (P \ 0.05), except ACD (P = 0.36). Corneal curvature measured with Pentacam AXL was significantly flatter then with IOL Master. The mean difference in AL was clinically insignificant (0.01 mm; 95% LoA 0.16 mm). Pentacam AXL yielded higher IOL power in 75% of eyes for Haigis formula and in 62% of eyes for SRK/T formula, with a mean difference within ± 0.5 D for 72 and 86% of eyes, respectively. Conclusions There were statistically significant differences between AL, K and WTW measurements obtained with the compared biometers. Flatter corneal curvature measurements on Pentacam AXL necessitate formulas optimisation for Pentacam AXL.

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“…It has been used as the gold standard in evaluation of new instruments, including the Lenstar device (HaagStreit) and the Pentacam device (Oculus) [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Comparison of keratometric measurements obtained by the Verion Image Guided System with optical biometry and auto-keratorefractometer

2016

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The aim of this study was to compare the keratometric measurements of Verion Image Guided System with an optical biometer (Zeiss IOLMaster 500, Carl Zeiss Meditec, Jena, Germany) and an automated keratorefractometer (AKR) (Topcon KR-8900, Topcon, Japan). In this prospective clinical trial, the right eyes of 52 patients with cataract were examined (mean age 62.25 ± 12.16 years). The measurements were taken by the three systems in a random order. Keratometric data, magnitude of astigmatism, and astigmatic axis measurements from all three instruments were compared. The results were evaluated using, intraclass correlation coefficients (ICC), Bland-Altman plots, and paired samples t tests. The mean flat/steep K of Verion, IOLMaster, and AKR were 43.22 ± 1.38D/44.23 ± 1.46D, 43.07 ± 1.26D/44.05 ± 1.34D, and 43.07 ± 1.31D/43.89 ± 1.42D, respectively. Flat K readings of Verion were higher than IOLMaster and AKR (p < 0.05 for both). Steep K readings were different for all three (p < 0.05). The magnitude of astigmatism by Verion and IOLMaster were 0.98 ± 0.65D and 0.98 ± 0.59D (p = 0.88). The mean astigmatism measured by the AKR was 0.82 ± 0.62D, less than the other two instruments (p < 0.001). Astigmatic axis measurements of Verion and AKR differed <10° in 38, between 10° and 20° in 5, and >20° in 9 eyes; the same difference was 30, 11, and 11 eyes, respectively, between Verion and IOLMaster. Although, keratometric and astigmatic results obtained from Verion were not completely interchangeable with IOLMaster and AKR, especially the agreement between Verion and IOLMaster was excellent with ICCs close to one. However, there were pronounced astigmatic axis measurement differences between three instruments.

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Automated keratometry in routine cataract surgery: Comparison of Scheimpflug and conventional values

Cited by 46 publications

References 20 publications

Comparability and repeatability of corneal astigmatism measurements using different measurement technologies

Comparability and repeatability of corneal astigmatism measurements using different measurement technologies

Comparison of anterior segment parameters and axial length measurements performed on a Scheimpflug device with biometry function and a reference optical biometer

Comparison of keratometric measurements obtained by the Verion Image Guided System with optical biometry and auto-keratorefractometer

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