Reliability of Pachymetry Measurement With FD-oCT, ORA, Confoscan 4 and Ultrasound

Repeatability and Reproducibility of Pachymetric Mapping With Fourier Domain Optical Coherence Tomography, Ocular Response Analyzer, Confoscan 4 and Ultrasound

The purpose of this study is to assess the repeatability, reproducibility, and agreement of central corneal thickness measured by Fourier Domain Optical Coherence tomography (FD-OCT, OptoVue, USA) with anterior corneal module, 20MHz ultrasound pachymetry equipped with Ocular response analyzer (ORA, Reichert Ophthalmic Instruments, USA) and 10MHz Ultrasound Pachymetry (USP).

Study Overview

• Status: Unknown
• Conditions: Keratitis

Detailed Description

Corneal thickness measurements are clinically important. Variation in corneal thickness affects the accuracy of applanation tonometry. A meta-analysis by Doughty and Zaman showed that a 10% change in central corneal thickness may result in an approximately 3.4-mmHg change in intraocular pressure.1 Accuracy of corneal thickness measurement is also important in considering eligibility for refractive surgery, and the amount of correction that can safely be performed. Underestimation of corneal thickness may lead to eligible patients being excluded for primary or enhancement refractive procedures. Overestimation may lead to over-ablation and inadvertent thinning of the stroma, thereby increasing the risk of iatrogenic keratectasia. Hence, studies assessing corneal thickness measurements by various instruments are of high clinical relevance.2-9 Fourier domain optical coherence tomography (FD-OCT, OptoVue, U.S.A), Confoscan 4 (CS-4, Nidek, USA) and ocular response analyzer (ORA, Reichert, USA) are non-invasive medical devices that have recently received FDA approval for measurement of the cornea thickness. However, the repeatability and reproducibility of these instruments remains unproven in the clinical settings. To our knowledge, this is the first study to describe agreement, repeatability and reproducibility in corneal pachymetric mapping between FD-OCT, ORA, CS-4 and conventional ultrasound (US), which has been the current reference corneal pachymetric mapping system for the majority of refractive surgeons.

• Study Type: Observational
• Enrollment (Anticipated): 100

Contacts and Locations

Study Locations

• Taiwan
  • Taipei County
    • Pan-Chiao, Taipei County, Taiwan, 220
      • Recruiting
      • Far Eastern Memorial Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 70 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Healthy volunteer who has no prior ocular disease history and prior intraocular surgical history

Description

Inclusion Criteria:

• Healthy Volunteers

Exclusion Criteria:

• Patients who had history of prior ocular surgery, ocular abnormalities other than cataract or refractive error or were unable to cooperate in the examination were excluded.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
FD-OCT, ORA, USP

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Repeatability and reproducibility of corneal thickness measurement	3 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Comparing central corneal thickness measurement among FD-OCT, ORA, and USP	3 months

Collaborators and Investigators

• Sponsor: Far Eastern Memorial Hospital

Study record dates

Study Major Dates

• Study Start: June 1, 2008
• Primary Completion (ANTICIPATED): January 1, 2009
• Study Completion (ANTICIPATED): June 1, 2009

Study Registration Dates

• First Submitted: February 4, 2009
• First Submitted That Met QC Criteria: February 5, 2009
• First Posted (ESTIMATE): February 6, 2009

Study Record Updates

• Last Update Posted (ESTIMATE): February 6, 2009
• Last Update Submitted That Met QC Criteria: February 5, 2009
• Last Verified: February 1, 2009

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Corneal Diseases; Keratitis
• Other Study ID Numbers: FEMH97010