Clinical trial NCT04578184: Epithelial Thickness Map
Official title: Comparison of Two Optical Coherence Tomography Devices in Corneal Epithelial Thickness Maps
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Keratoconus
Lead sponsor: Vienna Institute for Research in Ocular Surgery
Sponsor class: OTHER
First posted: 2020-10-08
Enrollment: 50
Sex: ALL
Minimum age (years): 21
Maximum age (years): 100
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: DIAGNOSTIC

Brief summary: In keratoconic eyes, the corneal epithelium shows a localized thinning over the cone that is surrounded by an annulus of epithelial thickening. It has been postulated that epithelial thickness mapping can be a sensitive tool for the keratoconus diagnosis. In keratoconus screening the 5 mm diameter of the corneal centrum may be sufficient while studies have shown that the cone apex is located in this area.

Aim of this study is to assess agreement and repeatability of epithelial thickness measurements using two optical coherence tomography devices in healthy and keratoconus corneas.

Secondary objective is to evaluate the differences between healthy and keratoconus eyes using epithelial thickness map data.

This is a prospective monocentric study that includes patients divided into two groups: patients with keratoconus and a control group formed out of patients without corneal pathologies. For each patient only one eye will be included and corneal measurements will be performed, focused on the corneal epithelium thickness.

Detailed description: In total 50 eyes of 50 patients will be included, divided into two groups: study group comprised of 20 eyes with diagnosed keratoconus and a control group formed out of 30 healthy eyes.

Patients included in the study will be measured with the corneal acquisition mode, also allowing for epithelium thickness data, on each device without pupil dilatation. After each measurement patients will be asked to blink in order to allow adequate tear-film recovery. Each patient will be measured three times with both devices. Only one visit will be necessary.

The order in which the measurements will be performed (Anterion or MS-39) will be randomised using randomised.org.

The corneal epithelial thickness will be measured as the distance between the air-tear and the epithelium-Bowman interfaces.

Main outcome variable:

- Mean differences in central corneal epithelial thickness between the devices investigated (+ limits of agreement (1.96xSD) between the investigated devices)

Secondary outcome variables:

* Repeatability coefficient (within subject standard deviation - SD) and coefficient of variation of the two devices
* Comparison in epithelial thickness between normal and keratoconus eyes
* Sensitivity and specificity of swept-source OCT device in keratoconus diagnosis

Eligibility criteria: Inclusion Criteria:

* Patient with diagnosed keratoconus (diagnosed using tomography and topography map changes and slit-lamp changes) and patients with healthy cornea
* Age 21 and older
* Signed informed consent

Exclusion Criteria:

* Previous ocular surgery
* Associated corneal pathologies (e.g. trauma, edema, scarring)
* In women of childbearing age, a pregnancy test will be performed before inclusion into the study.

Primary outcomes:
measure: Agreement between two ss-OCT devices in corneal epithelial thickness measurements (LoA in micrometer)
timeFrame: 6 months
Secondary outcomes:
measure: Repeatability between two ss-OCT devices in corneal epithelial thickness measurements (determination of within-subject standard deviation and Coefficient of variation)
timeFrame: 6 months
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Hanusch Hospital, Ophthalmology Department
Study officials:
affiliation: Head of Department of Ophthalmology, Professor, Principal Investigator
name: Oliver Findl, Prof., MD
role: PRINCIPAL_INVESTIGATOR
References: