Astigmatic Vector Analysis of Posterior Cornea - a Comparison Among Healthy, Forme Fruste and Overt Keratoconus Corneas
NCT ID: NCT02698709
Last Updated: 2016-03-04
Study Results
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Basic Information
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COMPLETED
698 participants
OBSERVATIONAL
2015-05-31
2015-09-30
Brief Summary
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Detailed Description
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Conditions
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Study Design
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CASE_CONTROL
RETROSPECTIVE
Study Groups
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Healthy corneas (C)
Corneas of normal candidates to refractive surgery who did not develop any sign of corneal ectasia after laser in situ keratomileusis during a two year follow-up period were analyzed by an Scheimpflug-based tomographer. Vector astigmatism analysis of anterior and posterior corneal surfaces were studied in accordance to method proposed by Thibos.
Analysis of anterior and posterior corneal surfaces
Corneal data obtained from a Scheimpflug-based topographer were converted to astigmatic vectors in accordance to the method proposed by Thibos
Overt keratoconus (Kc)
Whether both eyes manifested classic Kc-suggestive topographic features, such as corneal steepness higher than 47.20 diopters (D), superior-inferior asymmetry higher than 1.40 D and thinnest pachymetric reading lower than 500 micrometers. Such eyes were analyzed by an Scheimpflug-based tomographer. Vector astigmatism analysis of anterior and posterior corneal surfaces were studied in accordance to method proposed by Thibos.
Analysis of anterior and posterior corneal surfaces
Corneal data obtained from a Scheimpflug-based topographer were converted to astigmatic vectors in accordance to the method proposed by Thibos
Forme fruste keratoconus (FFKc)
Whether only one eye manifested classic Kc-suggestive topographic features, such as corneal steepness higher than 47.20 diopters (D), superior-inferior asymmetry higher than 1.40 D and thinnest pachymetric reading lower than 500 micrometers, and the fellow eye seemed unaffected. Such unaffected eyes were analyzed by an Scheimpflug-based tomographer. Vector astigmatism analysis of anterior and posterior corneal surfaces were studied in accordance to method proposed by Thibos.
Analysis of anterior and posterior corneal surfaces
Corneal data obtained from a Scheimpflug-based topographer were converted to astigmatic vectors in accordance to the method proposed by Thibos
Interventions
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Analysis of anterior and posterior corneal surfaces
Corneal data obtained from a Scheimpflug-based topographer were converted to astigmatic vectors in accordance to the method proposed by Thibos
Other Intervention Names
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Eligibility Criteria
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Inclusion Criteria
Exclusion Criteria
ALL
No
Sponsors
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University of Sao Paulo
OTHER
Responsible Party
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Giuliano de Oliveira Freitas, MD.
MD
Principal Investigators
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Milton R Alves, MD, PhD
Role: STUDY_DIRECTOR
Clínica Oftalmológica HCFM/USP
Locations
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Clínica Oftalmológica do Hospital de Clínicas - FMUSP
São Paulo, São Paulo, Brazil
Countries
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References
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Goebels S, Eppig T, Wagenpfeil S, Cayless A, Seitz B, Langenbucher A. Staging of keratoconus indices regarding tomography, topography, and biomechanical measurements. Am J Ophthalmol. 2015 Apr;159(4):733-8. doi: 10.1016/j.ajo.2015.01.014. Epub 2015 Jan 26.
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Gomes JA, Tan D, Rapuano CJ, Belin MW, Ambrosio R Jr, Guell JL, Malecaze F, Nishida K, Sangwan VS; Group of Panelists for the Global Delphi Panel of Keratoconus and Ectatic Diseases. Global consensus on keratoconus and ectatic diseases. Cornea. 2015 Apr;34(4):359-69. doi: 10.1097/ICO.0000000000000408.
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Ruisenor Vazquez PR, Galletti JD, Minguez N, Delrivo M, Fuentes Bonthoux F, Pfortner T, Galletti JG. Pentacam Scheimpflug tomography findings in topographically normal patients and subclinical keratoconus cases. Am J Ophthalmol. 2014 Jul;158(1):32-40.e2. doi: 10.1016/j.ajo.2014.03.018. Epub 2014 Apr 5.
Buhren J, Schaffeler T, Kohnen T. Validation of metrics for the detection of subclinical keratoconus in a new patient collective. J Cataract Refract Surg. 2014 Feb;40(2):259-68. doi: 10.1016/j.jcrs.2013.07.044. Epub 2013 Dec 18.
Galletti JD, Ruisenor Vazquez PR, Minguez N, Delrivo M, Bonthoux FF, Pfortner T, Galletti JG. Corneal asymmetry analysis by pentacam scheimpflug tomography for keratoconus diagnosis. J Refract Surg. 2015 Feb;31(2):116-23. doi: 10.3928/1081597X-20150122-07.
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Other Identifiers
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Clínica Oftalmológica HCFM/USP
Identifier Type: -
Identifier Source: org_study_id
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