Fourier Transform of Videokeratography Data: Clinical Usefulness in Moderate and Frome Fruste Keratoconus

Completed

• Conditions: Keratoconus

• Registration Number: NCT02617368
• Lead Sponsor: Democritus University of Thrace

Brief Summary

Primary objective of this study was evaluate the diagnostic capacity of fourier analysis of keratometric data in differentiating moderate KC and FFK from healthy corneas.

Study participants were recruited from the Cornea Outpatient service in a consecutive if eligible basis. Two study groups were formed: a)KC group included patients those were diagnosed and classified for moderate keratoconus according to the Amsler-Krumeich classification system, b) FFK group (FFKG) that included patients diagnosed with FFK, and c) Control group (CG) was formed by refractive surgery candidates. Pentacam (Pentacam HR, Oculus Optikgerate GmbH, Heidelberg, Germany)measurements were performed by the same experienced operator in a consistent way.

Detailed Description

Not available

Study Timeline

• Study Start: 2014-11
• Status Verified: 2015-11
• Primary Completion: 2015-11
• Study Completion: 2015-11
• Study First Submitted: 2015-11-23
• Study First Submitted QC: 2015-11-25
• Last Update Submitted: 2015-11-25
• Study First Posted: 2015-12-01
• Last Update Posted: 2015-12-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 185

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)
• diagnosed and classified for moderate keratoconus according to the Amsler-Krumeich classification system (KCG)

Exclusion Criteria

• for all 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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Spherical Eccentricity (SphEcc)	One Day	Spherical Eccentricity is the asphericity that is calculated
Spherical Component (SphRmin)	One Day	Spherical Component (SphRmin) displays the arithmetic mean of all radii of curvature for each ring
Total Astigmatism (Tast) which is the sum of Mean Astigmatism and Irregularities.	One Day	Total Astigmatism (Tast) is the sum of Mean Astigmatism and Irregularities.
Regular Astigmatism at the Center(AstC)	One Day	the regular astigmatic component is calculated in the center and it is derived from the second order component of Fourier Analysis
Mean Astigmatism (MAst)	One Day	Mean Astigmatism is the average of astigmatism at the center and the periphery (MAst)
Irregularitiy (Irr)	one Day
Maximum Decentration (MaxDec)	One Day	decentration or asymmetry of the astigmatic component which is derived from first order component of fourier analysis
Regular Astigmatism at the Periphery (AstP)	One day	the regular astigmatic component is calculated in the periphery and it is derived from the second order component of Fourier Analysis
Astigmatism at the Center plus the Irregularities (AstCir)	One day	the irregularities of the cornea which can not be corrected by sphere, cylinder or prism and it is derived from higher order components of Fourier Analysis of Keratometric Data

Trial Locations

Locations (1)

Eye Institute Of Thrace; 🇬🇷 Alexandroupolis, Evros, Greece