Comparison of Central Corneal Thickness Measurements by Contact and Non-contact Pachymetry Devices

Mayalı, Hüseyin; Altınışık, Muhammed; Diri, Ismail; Ilker, Sami; Kurt, Emin; Kayıkçıoğlu, Özcan

doi:10.5005/jp-journals-10078-1295

Cited by 5 publications

(6 citation statements)

References 22 publications

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“…Previous studies have similarly found that CCT measurements with ultrasound are slightly thicker than with optical biometers. 13,[24][25][26] Although statistically significant, the small overall difference in CCT between the PM1 and UP is not clinically significant; however, the 95% LoA ranging from 9.47 μm above to 24.63 μm below would suggest that the two devices are not directly interchangeable and therefore the same device should be used when monitoring CCT over time. Similar results have also been found in agreement studies using optical coherence tomography (OCT), which is currently widely used for quantitative and qualitative evaluation of anterior segment structures in a variety of clinical settings.…”

Section: Discussionmentioning

confidence: 94%

Repeatability and agreement of central corneal thickness measurements with a new handheld non‐contact pachymeter

Lawrenson

Gill

Masuid

et al. 2023

Ophthalmic Physiologic Optic

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PurposeTo 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.MethodsThree 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.ResultsThe 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).ConclusionsThe 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.

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Section: Discussionmentioning

confidence: 94%

Repeatability and agreement of central corneal thickness measurements with a new handheld non‐contact pachymeter

Lawrenson

Gill

Masuid

et al. 2023

Ophthalmic Physiologic Optic

View full text Add to dashboard Cite

show abstract

“…Previous studies have similarly found that CCT measurements with ultrasound are slightly thicker than with optical biometers. [20][21][22][23] Although statistically significant, the small overall difference in CCT between the PM1 and ultrasound biometry is not clinically significant, however the 95% limits of agreement ranging from 9.47 µm above to 24.63 µm below would suggest that the two devices are not directly interchangeable and therefore the same device should be used when monitoring CCT over time. Similar results have also been found in agreement studies using optical coherence tomography (OCT), which is currently widely used for quantitative and qualitative evaluation of anterior segment structures in a variety of clinical settings.…”

Section: Discussionmentioning

confidence: 95%

Repeatability and agreement of central corneal thickness measurements with a new handheld non-contact pachymeter

Lawrenson

Gill

Masuid

et al. 2023

Preprint

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Purpose: To compare the repeatability of central corneal thickness (CCT) measurements taken with a new hand-held 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 LS900 and Oculus Pentacam HR in a random order. This was followed by three measurements with a hand-held ultrasound pachymeter (UP) (Pachmate-2). Repeatability and the repeatability limit were calculated with 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 SD 33.43 μm, 558.62 SD 31.46 μm, 549.41 SD 31.00 μm, and 539.73 SD 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 μm 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.

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“…Finally there is the toxicity of topical anaesthetic agents which are necessary for ultrasound pachymetry [18] . Apart from ultrasound pachymetry a number of non-contacttechniques have been developed and established which are able to measure CCT [9,[11][12][19][20][21][22][23][24][25] . The goal of this study was to evaluate the feasibility of different techniques to measure CCT in the perioperative course of uneventful cataract surgery using phacoemulsification.…”

Section: Measuring Corneal Thickness Perioperatively Using Three Diff...mentioning

confidence: 99%

“…This results in corneal swelling and thereby an increase in central corneal thickness (CCT) as an expression of endothelial decompensation. Extent and decrease of corneal swelling prove the endothelial recovery and compensation of its function [3,[6][7][8][9][10][11][12][13][14] . A high preoperative endothelial cell count (ECC) does not guarantee an uncomplicated intra-and postoperative course and a low ECC does not make corneal complications not inevitable.…”

Section: Introductionmentioning

confidence: 99%

Monitoring of central corneal thickness after phacoemulsification—comparison of statical and rotating Scheimpflug pachymetry, and spectral-domain OCT

Handzel¹,

Wegener²

2022

Int J Ophthalmol

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AIM: To explore the possibility of deploying three contactless devices (static and rotating Scheimpflug technology, spectral domain optical coherence tomography) for measuring central corneal thickness (CCT) in preoperative and postoperative examinations of cataract patients. METHODS: Totally 72 patients who had undergone surgery without complications were selected. The CCT was measured prior to the operation, as well as on the first, 5th-7th and 28th day following the operation using the Nidek NT 530-P, Sirius®, and Topcon OCT-2000 devices. RESULTS: A significant postoperative increase and subsequent decrease in CCT was identified with all three devices. The correlations were highly significant and thus reflect a very good degree of comparability at all times with the exception of the rotating Scheimpflug camera. The postoperative results from the latter differed significantly from the other devices. The correlations were Sirius/Topcon (P=0.010) and Sirius/Nidek (P<0.0005). No statistically significant difference could be identified in the comparison between Topcon and Nidek (P=0.056). CONCLUSION: All three devices are suitable for postoperative monitoring of CCT. The measurement results are only comparable to a limited extent and not interchangeable in the course of treating a single patient. This is due to the different imaging technology used in the devices and the resulting modalities for conducting the measurements.

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Comparison of Central Corneal Thickness Measurements by Contact and Non-contact Pachymetry Devices

Cited by 5 publications

References 22 publications

Repeatability and agreement of central corneal thickness measurements with a new handheld non‐contact pachymeter

Repeatability and agreement of central corneal thickness measurements with a new handheld non‐contact pachymeter

Repeatability and agreement of central corneal thickness measurements with a new handheld non-contact pachymeter

Monitoring of central corneal thickness after phacoemulsification—comparison of statical and rotating Scheimpflug pachymetry, and spectral-domain OCT

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