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Intraocular lens power calculation in keratoconus; A review of literature

PURPOSE: To review the published literature regarding cataract surgery in keratoconus (KCN) patients with emphasis on challenges encountered during intraocular lens (IOL) power calculation and their solutions. METHODS: A literature review was performed to investigate all the relevant articles on the...

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Autores principales: Ghiasian, Leila, Abolfathzadeh, Navid, Manafi, Navid, Hadavandkhani, Ali
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6611933/
https://www.ncbi.nlm.nih.gov/pubmed/31317089
http://dx.doi.org/10.1016/j.joco.2019.01.011
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author Ghiasian, Leila
Abolfathzadeh, Navid
Manafi, Navid
Hadavandkhani, Ali
author_facet Ghiasian, Leila
Abolfathzadeh, Navid
Manafi, Navid
Hadavandkhani, Ali
author_sort Ghiasian, Leila
collection PubMed
description PURPOSE: To review the published literature regarding cataract surgery in keratoconus (KCN) patients with emphasis on challenges encountered during intraocular lens (IOL) power calculation and their solutions. METHODS: A literature review was performed to investigate all the relevant articles on the advancements of IOL calculations in KCN patients. RESULTS: Cataract surgery in keratoconic eyes can improve patients' refraction, and proper patient selection and IOL calculation methods are necessary to get the best results. The main problem in KCN patients is unreliable biometric measurements. It is more difficult to make conclusions in more advanced keratoconic corneas, as the steep keratometric values in these eyes will result in the selection of a low-power IOL. Presence of a low-power IOL will yield in extreme postoperative hyperopia, and IOL exchange might be mandatory. In cases in which keratoplasty may be needed in the future, contact lens fitting can help surgeons make a better decision preoperatively. Axial length (AL) measurements may have better repeatability and reproducibility than keratometry (K) readings in keratoconic eyes. SRK II formula may provide the most accurate IOL power in mild KCN. There is still not a comprehensive consensus of which formula is the best one in moderate and severe KCN, as the literature is limited in this subject. CONCLUSIONS: Various methods of IOL power calculation optimization and recommendations may hold the key to improve surgical outcomes in keratoconic eyes. There are multiple sources of biometric error in KCN patients, hence IOL calculation methods may not be as efficient as expected in these eyes.
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spelling pubmed-66119332019-07-17 Intraocular lens power calculation in keratoconus; A review of literature Ghiasian, Leila Abolfathzadeh, Navid Manafi, Navid Hadavandkhani, Ali J Curr Ophthalmol Article PURPOSE: To review the published literature regarding cataract surgery in keratoconus (KCN) patients with emphasis on challenges encountered during intraocular lens (IOL) power calculation and their solutions. METHODS: A literature review was performed to investigate all the relevant articles on the advancements of IOL calculations in KCN patients. RESULTS: Cataract surgery in keratoconic eyes can improve patients' refraction, and proper patient selection and IOL calculation methods are necessary to get the best results. The main problem in KCN patients is unreliable biometric measurements. It is more difficult to make conclusions in more advanced keratoconic corneas, as the steep keratometric values in these eyes will result in the selection of a low-power IOL. Presence of a low-power IOL will yield in extreme postoperative hyperopia, and IOL exchange might be mandatory. In cases in which keratoplasty may be needed in the future, contact lens fitting can help surgeons make a better decision preoperatively. Axial length (AL) measurements may have better repeatability and reproducibility than keratometry (K) readings in keratoconic eyes. SRK II formula may provide the most accurate IOL power in mild KCN. There is still not a comprehensive consensus of which formula is the best one in moderate and severe KCN, as the literature is limited in this subject. CONCLUSIONS: Various methods of IOL power calculation optimization and recommendations may hold the key to improve surgical outcomes in keratoconic eyes. There are multiple sources of biometric error in KCN patients, hence IOL calculation methods may not be as efficient as expected in these eyes. Elsevier 2019-03-15 /pmc/articles/PMC6611933/ /pubmed/31317089 http://dx.doi.org/10.1016/j.joco.2019.01.011 Text en © 2019 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 Article
Ghiasian, Leila
Abolfathzadeh, Navid
Manafi, Navid
Hadavandkhani, Ali
Intraocular lens power calculation in keratoconus; A review of literature
title Intraocular lens power calculation in keratoconus; A review of literature
title_full Intraocular lens power calculation in keratoconus; A review of literature
title_fullStr Intraocular lens power calculation in keratoconus; A review of literature
title_full_unstemmed Intraocular lens power calculation in keratoconus; A review of literature
title_short Intraocular lens power calculation in keratoconus; A review of literature
title_sort intraocular lens power calculation in keratoconus; a review of literature
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6611933/
https://www.ncbi.nlm.nih.gov/pubmed/31317089
http://dx.doi.org/10.1016/j.joco.2019.01.011
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