Clinical trial NCT02519985: Repeatability and Reproducibility of the ArcScan Insight 100 VHF Digital Ultrasound
Official title: Repeatability and Reproducibility of Corneal and Anterior Segment Measurements by ArcScan Insight 100 Very High-frequency Digital Ultrasound
Study type: INTERVENTIONAL
Overall status: SUSPENDED
Phase: NA
Conditions: Corneal Thickness Measurement
Epithelial Thickness Measurement
Anterior Eye Segment Measurements
Keywords: VHF digital ultrasound
Corneal thickness
Epithelial thickness
Angle diameter
Sulcus diameter
Anterior chamber depth
Repeatability
Reproducibility
Lead sponsor: London Vision Clinic
Sponsor class: OTHER
Collaborators: name: Arcscan, Inc.
First posted: 2015-08-11
Enrollment: 40
Sex: ALL
Minimum age (years): 21
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

Brief summary: The purpose of this study is to evaluate the repeatability and reproducibility of corneal (including corneal, epithelial, stromal, and LASIK flap thickness) and anterior segment measurements using the ArcScan Insight 100 very high-frequency digital ultrasound arc-scanner.

Detailed description: Very high-frequency (VHF) digital ultrasound was first used in 1993 to obtain images of the cornea (the window at the front of the eye) and anterior segment (the space behind the cornea including the iris and the lens). A commercially available instrument, called the Artemis 2, has been used in routine clinical practice since 2001. The Artemis 2 was CE approved as well as having FDA approval (the US equivalent of the CE mark).

The ArcScan Insight 100 VHF digital ultrasound scanner is a new instrument so does not yet have a CE mark. However, the ArcScan Insight 100 is an upgraded version of the Artemis 2, so any differences are improvements to components, but the measurement method remains essentially the same.

The aim of the study is to establish the repeatability (i.e. the variability in measurements taken by a single examiner during a single visit) and reproducibility (i.e. the variability in measurements taken in the same conditions between two examiners) of the ArcScan Insight 100 device for measuring corneal and anterior segment parameters.

Eligibility criteria: INCLUSION CRITERIA Only patients who are medically suitable for corneal refractive surgery can be included in the study.

As general inclusion criteria the following aspects are defined:

* Subjects should be 21 years of age or older.
* Contact lens wearers must stop wearing their contact lenses at least four weeks per decade of wear before baseline measurements in case of hard contact lenses and one week before baseline measurements in case of soft contact lenses.
* Patient will be able to understand the patient information and willing to sign an informed consent.

For the repeatability and reproducibility phase using normal eyes of the study:

* Eyes with no ocular pathology
* Eyes with no previous ocular or corneal surgery

For the repeatability and reproducibility phase using post-LASIK eyes of the study:

• Eyes between 3 and 9 months after LASIK or SMILE

For the comparison of ArcScan Insight 100 VHF digital ultrasound with RTVue OCT

• Either eyes before or after corneal refractive surgery

EXCLUSION CRITERIA

* Previous ocular or corneal surgery (for normal eyes)
* Patient not being able to tolerate local or topical anesthesia
* Patient has active conjunctivitis or any active ocular infection or inflammation
* Patient has a corneal ulcer
* Patient has an open wound on the corneal epithelium
* Patient has compromised epithelium (e.g. ≥Grade 3 superficial punctate keratitis)
* Pregnancy

Primary outcomes:
measure: Repeatability of ArcScan Insight 100 corneal scans in normal eyes (standard deviation)
timeFrame: 1 day
Secondary outcomes:
measure: Reproducibility of ArcScan Insight 100 corneal scans in normal eyes (between-operator standard deviation)
timeFrame: 1 day
measure: Repeatability of ArcScan Insight 100 anterior segment scans in normal eyes (standard deviation)
timeFrame: 1 day
measure: Reproducibility of ArcScan Insight 100 anterior segment scans in normal eyes (between-operator standard deviation)
timeFrame: 1 day
measure: Repeatability of ArcScan Insight 100 corneal scans in eyes after corneal laser refractive surgery (standard deviation)
timeFrame: 1 day
measure: Reproducibility of ArcScan Insight 100 corneal scans in eyes after corneal laser refractive surgery (between-operator standard deviation)
timeFrame: 1 day
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: London Vision Clinic
Study officials:
affiliation: London Vision Clinic
name: Dan Z Reinstein, MD MA
role: PRINCIPAL_INVESTIGATOR
References:
citation: Reinstein DZ, Silverman RH, Raevsky T, Simoni GJ, Lloyd HO, Najafi DJ, Rondeau MJ, Coleman DJ. Arc-scanning very high-frequency digital ultrasound for 3D pachymetric mapping of the corneal epithelium and stroma in laser in situ keratomileusis. J Refract Surg. 2000 Jul-Aug;16(4):414-30. doi: 10.3928/1081-597X-20000701-04.
citation: Paul T, Lim M, Starr CE, Lloyd HO, Coleman DJ, Silverman RH. Central corneal thickness measured by the Orbscan II system, contact ultrasound pachymetry, and the Artemis 2 system. J Cataract Refract Surg. 2008 Nov;34(11):1906-12. doi: 10.1016/j.jcrs.2008.07.013.
citation: Ursea R, Feng M, Urs R, RoyChoudhury A, Silverman RH. Comparison of artemis 2 ultrasound and Visante optical coherence tomography corneal thickness profiles. J Refract Surg. 2013 Jan;29(1):36-41. doi: 10.3928/1081597X-20121126-01. Epub 2012 Nov 30.
citation: Ogbuehi KC, Osuagwu UL. Repeatability and interobserver reproducibility of Artemis-2 high-frequency ultrasound in determination of human corneal thickness. Clin Ophthalmol. 2012;6:761-9. doi: 10.2147/OPTH.S31690. Epub 2012 May 21.
citation: Pinero DP, Plaza AB, Alio JL. Anterior segment biometry with 2 imaging technologies: very-high-frequency ultrasound scanning versus optical coherence tomography. J Cataract Refract Surg. 2008 Jan;34(1):95-102. doi: 10.1016/j.jcrs.2007.08.033.