Reliability of Topography Measurements in Keratoconus

April 19, 2019 updated by: Seth M Pantanelli, Milton S. Hershey Medical Center

Repeatability and Reliability of Galilei Corneal Topographer Measurements in Keratoconus

The purpose of this study is to assess the reliability and repeatability of the parameters obtained using the Galilei dual-scheimpflug corneal topographer for monitoring progression in eyes with keratoconus.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Keratoconus is a progressive corneal degeneration characterized by progressive steepening and thinning of the central or paracentral cornea leading to corneal protrusion and resulting irregular astigmatism and high myopia. This disorder is usually bilateral and is linked to atopy and excessive eye rubbing, although the precise pathophysiology behind development of this condition is unclear. Keratoconus is the most common corneal degeneration in the United States, affecting between 50 and 230 subjects per 100,000 population.

Early diagnosis and appropriate management of keratoconus relies greatly on accurate assessment of corneal topographic measurements. It is therefore imperative that the data obtained via corneal topography devices is accurate and reliable.

The GALILEI Dual Scheimpflug Analyzer integrates Placido disc topography and dual Scheimpflug tomography to assess anterior and posterior corneal curvature data. Although there have been several studies performed assessing the ability of the Galilei to accurately distinguish keratoconus from unaffected eyes and investigating interdevice reliability between the Galilei analyzer and other tomographers, to our knowledge the repeatability of measurements obtained in this population via the Galilei device has been incompletely evaluated to date.

Corneal topography data obtained via the Galilei device is relied upon heavily in clinical decision making for keratoconic patients both in the Hershey Eye Clinic and in a great number of ophthalmology practices world-wide. It is vital that the accuracy and repeatability of these measurements obtained via the Galilei device are investigated.

The primary endpoint to be measured in the study will be the maximum (steepest) and minimum (flattest) keratometry values in the central zone.

Secondary endpoints will be maximum keratometry across the entire area scanned, axis of corneal astigmatism, anterior and posterior best fit spheres in float mode with the diameter set to 8 mm, maximum anterior and posterior elevations, thinnest corneal thickness, and corneal asphericity at 6 mm, root mean square (RMS) of the HOAs, RMS of the third-order coma, coma axis, vertical and horizontal coma and spherical aberration.

Study Type

Observational

Enrollment (Actual)

86

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Hershey, Pennsylvania, United States, 17033
        • Penn State Hershey Eye Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

This is a prospective study of patients seen at the Penn State Eye Center who have been diagnosed with keratoconus and are undergoing Galilei corneal topography. Patients will be selected to participate in the study based on inclusion/exclusion criteria. Each patient in the study will undergo five consecutive corneal topography measurements per keratoconic eye.

Description

Inclusion Criteria:

  • Patientswho are older than 18 years of age
  • Patients who are scheduled to undergo Galilei dual-scheimpflug corneal topography testing
  • Patients who have been diagnosed with keratoconus
  • Measurements with a reported reliability of 'good' from the topographer

Exclusion Criteria:

  • Patients who have undergone any prior surgical intervention involving the cornea (i.e. cornea transplant or INTACS, or corneal cross linking)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Only
  • Time Perspectives: Cross-Sectional

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Keratoconic Patients
Diagnostic test: Galilei Corneal Topographer
A series of five measurements via the Galilei corneal topographer of each keratoconic eye in quick succession

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Maximum (steepest) and minimum (flattest) keratometry values in the central zone
Time Frame: Measured at day 0 of study enrollment
Assessment of the steepness of the cornea
Measured at day 0 of study enrollment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Thinnest pachymetry
Time Frame: Measured at day 0 of study enrollment
The thinnest area of the cornea
Measured at day 0 of study enrollment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Milton S. Hershey Medical Center

Investigators

  • Principal Investigator: Seth Pantanelli, MD, Milton S. Hershey Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 11, 2017

Primary Completion (Actual)

March 31, 2019

Study Completion (Actual)

March 31, 2019

Study Registration Dates

First Submitted

March 28, 2018

First Submitted That Met QC Criteria

April 18, 2018

First Posted (Actual)

April 27, 2018

Study Record Updates

Last Update Posted (Actual)

April 22, 2019

Last Update Submitted That Met QC Criteria

April 19, 2019

Last Verified

April 1, 2019

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00007951

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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