Repeatability, Reproducibility and Comparison of Cirrus OCT, RTVue OCT, MS-39 OCT, and Insight 100 VHFDU

London Vision Clinic

Status: Suspended

Conditions: Epithelial Thickness Measurement; Corneal Thickness Measurement; SMILE Cap Thickness Measurement; LASIK Flap Thickness Measurement

Treatments: Device: Carl Zeiss Meditec Cirrus HD OCT 5000; Device: Optovue RTVue OCT; Device: ArcScan Insight 100 very high-frequency digital ultrasound; Device: CSO MS-39 OCT

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT03473847

LOVC-006

Details and patient eligibility

About

The purpose of this study is to evaluate the repeatability and reproducibility of corneal, epithelial, and LASIK flap thickness using the Carl Zeiss Meditec Cirrus HD OCT 5000, Optovue RTVue OCT, CSO MS-39 OCT, and ArcScan Insight 100 very high-frequency digital ultrasound arc-scanner.

Full description

Very high-frequency (VHF) digital ultrasound was first used in 1993 to obtain images and measure the thickness of the cornea (the window at the front of the eye) and the layers within the cornea, such as the epithelium (the layer of skin on the surface of the cornea). A commercially available instrument, known as the Artemis, has been used in routine clinical practice since 2001. The ArcScan Insight 100 VHF digital ultrasound scanner is an updated version, which obtained CE mark in 2016.

Optical coherence tomography (OCT) is another method of measuring the thickness of the cornea and the corneal epithelium. OCT has been used for measuring corneal thickness since 1997 and the technology had evolved to also measure epithelial thickness since 2012. There are currently three OCT scanners capable of measuring epithelial thickness; Carl Zeiss Meditec Cirrus HD OCT 5000, Optovue RTVue OCT, CSO MS-39 OCT.

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) for each of the four devices for measuring corneal thickness and epithelial thickness.

Enrollment: 242 estimated patients

Sex: All

Ages: 21 to 70 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

Only patients who are medically suitable for corneal laser 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 normal eye populations:

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

For the post-op eye populations:

• Eyes between 3 and 9 months after LASIK or SMILE

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

Trial design

Primary purpose: Diagnostic

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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242 participants in 4 patient groups

Repeatability and Reproducibility - Normal eyes

Experimental group

Description:

This arm will include 20 eyes of 20 patients with no previous ocular surgery. The research participant will be scanned a number of times using each of the four devices (the Insight 100 VHF digital ultrasound scanner, the Cirrus HD OCT 5000, the RTVue OCT, and the MS-39 OCT). The scan sequence will be undertaken on a single day as follows: 1. 5 consecutive repeated scans of the cornea will be performed by the first operator using each of the four devices (expected total time approximately 5 minutes for each OCT scan set and 15 minutes for the Insight 100 scan set). 2. There will be a break of about 30 minutes. 3. 5 consecutive repeated scans of the cornea will be performed by the second operator using each of the four devices (expected total time approximately 5 minutes for each OCT scan set and 15 minutes for the Insight 100 scan set).

Treatment:

Device: ArcScan Insight 100 very high-frequency digital ultrasound

Device: CSO MS-39 OCT

Device: Carl Zeiss Meditec Cirrus HD OCT 5000

Device: Optovue RTVue OCT

Repeatability and Reproducibility - Post-op eyes

Experimental group

Description:

This arm will include 20 eyes of 20 patients between 3 and 9 months after corneal laser refractive surgery. The research participant will be scanned a number of times using each of the four devices (the Insight 100 VHF digital ultrasound scanner, the Cirrus HD OCT 5000, the RTVue OCT, and the MS-39 OCT). The scan sequence will be undertaken on a single day as follows: 1. 5 consecutive repeated scans of the cornea will be performed by the first operator using each of the four devices (expected total time approximately 5 minutes for each OCT scan set and 15 minutes for the Insight 100 scan set). 2. There will be a break of about 30 minutes. 3. 5 consecutive repeated scans of the cornea will be performed by the second operator using each of the four devices (expected total time approximately 5 minutes for each OCT scan set and 15 minutes for the Insight 100 scan set).

Treatment:

Device: ArcScan Insight 100 very high-frequency digital ultrasound

Device: CSO MS-39 OCT

Device: Carl Zeiss Meditec Cirrus HD OCT 5000

Device: Optovue RTVue OCT

Comparison between devices - Normal eyes

Experimental group

Description:

This arm will include 101 eyes of 101 patients with no previous ocular surgery. The research participant will be scanned once using each of the four devices (the Insight 100 VHF digital ultrasound scanner, the Cirrus HD OCT 5000, the RTVue OCT, and the MS-39 OCT). Expected total time approximately 20 minutes to complete all four scans.

Treatment:

Device: ArcScan Insight 100 very high-frequency digital ultrasound

Device: CSO MS-39 OCT

Device: Carl Zeiss Meditec Cirrus HD OCT 5000

Device: Optovue RTVue OCT

Comparison between devices - Post-op eyes

Experimental group

Description:

This arm will include 101 eyes of 101 patients between 3 and 9 months after corneal laser refractive surgery. The research participant will be scanned once using each of the four devices (the Insight 100 VHF digital ultrasound scanner, the Cirrus HD OCT 5000, the RTVue OCT, and the MS-39 OCT). Expected total time approximately 20 minutes to complete all four scans.

Treatment:

Device: ArcScan Insight 100 very high-frequency digital ultrasound

Device: CSO MS-39 OCT

Device: Carl Zeiss Meditec Cirrus HD OCT 5000

Device: Optovue RTVue OCT