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Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus

PURPOSE: To determine the repeatability of corneal thickness measurements with Scheimpflug (Pentacam) and slit scanning (Orbscan) imaging techniques in different grades of keratoconus. METHODS: This study was conducted as a cross-sectional research. Imaging with Orbscan and Pentacam was performed on...

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Autores principales: Aghazadeh Amiri, Mohammad, Hashemi, Hassan, Ramin, Shahroukh, Yekta, Abbasali, Taheri, Azadeh, Nabovati, Payam, Khabazkhoob, Mehdi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5362393/
https://www.ncbi.nlm.nih.gov/pubmed/28367522
http://dx.doi.org/10.1016/j.joco.2016.09.005
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author Aghazadeh Amiri, Mohammad
Hashemi, Hassan
Ramin, Shahroukh
Yekta, Abbasali
Taheri, Azadeh
Nabovati, Payam
Khabazkhoob, Mehdi
author_facet Aghazadeh Amiri, Mohammad
Hashemi, Hassan
Ramin, Shahroukh
Yekta, Abbasali
Taheri, Azadeh
Nabovati, Payam
Khabazkhoob, Mehdi
author_sort Aghazadeh Amiri, Mohammad
collection PubMed
description PURPOSE: To determine the repeatability of corneal thickness measurements with Scheimpflug (Pentacam) and slit scanning (Orbscan) imaging techniques in different grades of keratoconus. METHODS: This study was conducted as a cross-sectional research. Imaging with Orbscan and Pentacam was performed on patients with different grades of keratoconus. With each device, 3 measurements were taken at 10 min intervals. Repeatability indices in different grades of keratoconus were calculated for each device. RESULTS: Seventy-four eyes of 42 keratoconus patients were enrolled. Repeatability index (RI) of central corneal thickness (CCT) measurements in keratoconus grade 1, 2, and 3, were 12.8, 9.9, and 24.2 with Pentacam, and 23.6, 26.3, and 59.3 with Orbscan, respectively. For the thinnest point, these figures were 9.6, 8.0, and 35.7 with Pentacam and 19.5, 16.6, and 26.8 with Orbscan, respectively. The 95% limit of agreement (LOA) between Pentacam and Orbscan in measuring CCT and thinnest point in grade 1 were −25.5–47.7 mic and −33.3–32.8 mic, respectively. These results for grade 2 were −9.8–50.6 mic and −26.2–43.7 mic, respectively. In grade 3, 95% LoA were −20–64.6 mic and −31.4–60.5 mic, respectively. CONCLUSIONS: The results of this study showed that although repeated measurements of the CCT with Orbscan and Pentacam are strongly correlated, repeatability values of CCT measurements significantly decrease at more advanced grades of keratoconus. In all keratoconus grades, repeatability of CCT measurements was better with Pentacam than Orbscan. These findings indicate that corneal thickness readings have less validity in patients with advanced keratoconus.
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spelling pubmed-53623932017-03-31 Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus Aghazadeh Amiri, Mohammad Hashemi, Hassan Ramin, Shahroukh Yekta, Abbasali Taheri, Azadeh Nabovati, Payam Khabazkhoob, Mehdi J Curr Ophthalmol Original Research PURPOSE: To determine the repeatability of corneal thickness measurements with Scheimpflug (Pentacam) and slit scanning (Orbscan) imaging techniques in different grades of keratoconus. METHODS: This study was conducted as a cross-sectional research. Imaging with Orbscan and Pentacam was performed on patients with different grades of keratoconus. With each device, 3 measurements were taken at 10 min intervals. Repeatability indices in different grades of keratoconus were calculated for each device. RESULTS: Seventy-four eyes of 42 keratoconus patients were enrolled. Repeatability index (RI) of central corneal thickness (CCT) measurements in keratoconus grade 1, 2, and 3, were 12.8, 9.9, and 24.2 with Pentacam, and 23.6, 26.3, and 59.3 with Orbscan, respectively. For the thinnest point, these figures were 9.6, 8.0, and 35.7 with Pentacam and 19.5, 16.6, and 26.8 with Orbscan, respectively. The 95% limit of agreement (LOA) between Pentacam and Orbscan in measuring CCT and thinnest point in grade 1 were −25.5–47.7 mic and −33.3–32.8 mic, respectively. These results for grade 2 were −9.8–50.6 mic and −26.2–43.7 mic, respectively. In grade 3, 95% LoA were −20–64.6 mic and −31.4–60.5 mic, respectively. CONCLUSIONS: The results of this study showed that although repeated measurements of the CCT with Orbscan and Pentacam are strongly correlated, repeatability values of CCT measurements significantly decrease at more advanced grades of keratoconus. In all keratoconus grades, repeatability of CCT measurements was better with Pentacam than Orbscan. These findings indicate that corneal thickness readings have less validity in patients with advanced keratoconus. Elsevier 2016-10-08 /pmc/articles/PMC5362393/ /pubmed/28367522 http://dx.doi.org/10.1016/j.joco.2016.09.005 Text en Copyright © 2017, Iranian Society of Ophthalmology. Production and hosting by Elsevier B.V. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Original Research
Aghazadeh Amiri, Mohammad
Hashemi, Hassan
Ramin, Shahroukh
Yekta, Abbasali
Taheri, Azadeh
Nabovati, Payam
Khabazkhoob, Mehdi
Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus
title Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus
title_full Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus
title_fullStr Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus
title_full_unstemmed Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus
title_short Corneal thickness measurements with Scheimpflug and slit scanning imaging techniques in keratoconus
title_sort corneal thickness measurements with scheimpflug and slit scanning imaging techniques in keratoconus
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5362393/
https://www.ncbi.nlm.nih.gov/pubmed/28367522
http://dx.doi.org/10.1016/j.joco.2016.09.005
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