Clinical trial NCT00838422: Reliability of Pachymetry Measurement With FD-oCT, ORA, Confoscan 4 and Ultrasound
Official title: Repeatability and Reproducibility of Pachymetric Mapping With Fourier Domain Optical Coherence Tomography, Ocular Response Analyzer, Confoscan 4 and Ultrasound
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Keratitis
Lead sponsor: Far Eastern Memorial Hospital
Sponsor class: OTHER
First posted: 2009-02-06
Enrollment: 100
Sex: ALL
Minimum age (years): 20
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Healthy volunteer who has no prior ocular disease history and prior intraocular surgical history

Brief summary: 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).

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.

Eligibility criteria: 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.

Primary outcomes:
measure: Repeatability and reproducibility of corneal thickness measurement
timeFrame: 3 months
Secondary outcomes:
measure: Comparing central corneal thickness measurement among FD-OCT, ORA, and USP
timeFrame: 3 months
Other outcomes:
Locations:
city: Pan-Chiao
country: Taiwan
facility: Far Eastern Memorial Hospital
state: Taipei County
Study officials:
affiliation: Far Eastern Memorial Hospital
name: Shu-Wen Chang, MD
role: PRINCIPAL_INVESTIGATOR
References: