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Diagnostic Capacity of Keratoconus Match Index and Keratoconus Match Probability in Forme Fruste Keratoconus

This study has been completed.
Information provided by (Responsible Party):
Georgios Labiris, Democritus University of Thrace Identifier:
First received: July 22, 2012
Last updated: January 14, 2017
Last verified: January 2017

Primary objective of this study was to evaluate the diagnostic capability of keratoconus match index (KMI) and keratoconus match probability (KMP) indexes in forme fruste keratoconus (FFK), and their association with a series of Pentacam-derived keratconus (KC) indexes. KMI and KMP parameters are KC-specifc indexes that are measured by Ocular Response Analyzer (ORA), based on the distinct ORA-derived waveform characteristics of KC eyes.

Study participants were recruited from the Cornea Outpatient service in a consecutive if eligible basis. Two study groups were formed: a) FFK group (FFKG) that included patients diagnosed with FFK, and, b) Control group (CG) was formed by refractive surgery candidates.

All ORA (Reichert Ophthalmic Instrument, Buffalo, NY, USA, software version: 3.01)and Pentacam (Pentacam HR, Oculus Optikgerate GmbH, Heidelberg, Germany)measurements were performed by the same experienced operator in a consistent way

Forme Fruste Keratoconus (FFK)

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Diagnostic Capacity of Keratoconus Match Index and Keratoconus Match Probability in Forme Fruste Keratoconus

Resource links provided by NLM:

Further study details as provided by Democritus University of Thrace:

Primary Outcome Measures:
  • Keratoconus Match Index (KMI) [ Time Frame: one day ]

    KMI is the outcome of a neural network calculation of seven ORA-derived waveform scores and represents the similarity of the waveform of the examined eye against the same average waveform scores of the keratoconus eyes in the machine's database.

    Receiver operating characteristics (ROC) curves were applied to determine the overall predictive accuracy of KMI parameter,as described by the area under the curve (AUC), in differentiating FFK cases from normal ones. The impact of Pentacam-derived KC related indexes on KMI was assessed with stepwise forward multivariate regression analysis.

Enrollment: 120
Study Start Date: November 2011
Study Completion Date: July 2012
Primary Completion Date: June 2012 (Final data collection date for primary outcome measure)
Forme Fruste Keratoconus Group (FFKG)
Forme Fruste Keratoconus Group (FFKG) included patients diagnosed with FFK.
Control Group (CG)
Control group(CG) was formed by refractive surgery candidates.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
All participants were recruited from the Outpatients Cornea service, in a consecutive if eligible basis

Inclusion Criteria:

  • diagnosis of keratoconus KC in the fellow eye according to the Amsler-Krumleich criteria (FFKG)
  • KISA index between 60 and 100% in the FFK eye (FFKG)
  • lack of any KC-related findings / signs in the slit-lamp biomicroscopy (FFKG)
  • uneventful ophthalmologic history (CG)
  • no indications of corneal pathology in slit-lamp biomicroscopy and Placido disk-based videokeratography (CG)
  • KISA index value less than 60% (CG)

Exclusion Criteria:

for both study groups:

  • previous incisional eye surgery
  • corneal scars and opacities
  • history of herpetic keratitis, severe eye dryness
  • pregnancy or nursing
  • current corneal infection
  • glaucoma
  • suspicion for glaucoma
  • IOP lowering treatment
  • underlying autoimmune disease
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Please refer to this study by its identifier: NCT01654614

Eye Institute of Thrace (ΕΙΤ)
Alexandroupolis, Evros, Greece, 68100
Sponsors and Collaborators
Democritus University of Thrace
  More Information

Responsible Party: Georgios Labiris, Senior Lecturer of Ophthalmology, Democritus University of Thrace Identifier: NCT01654614     History of Changes
Other Study ID Numbers: 62/18.07.2012
Study First Received: July 22, 2012
Last Updated: January 14, 2017

Keywords provided by Democritus University of Thrace:
Keratoconus match index
keratoconus probability index
ocular response analyzer
forme fruste keratoconus

Additional relevant MeSH terms:
Corneal Diseases
Eye Diseases processed this record on May 25, 2017