Clinical trial NCT04668924: Epi-on PiXL for the Treatment of Progressive Keratoconus.
Official title: Prospective Evaluation of Photorefractive Intrastromal Crosslinking (PiXL) Without Epithelium Debridement (Epi-on) in High Oxygen for Progressive Keratoconus.
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Keratoconus
Corneal Crosslinking
Corneal Densitometry
Scheimpflug Photography
Corneal Disorder
Eye Diseases
Lead sponsor: Umeå University
Sponsor class: OTHER
Collaborators: name: Glaukos Corporation
First posted: 2020-12-16
Enrollment: 32
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: The purpose of this study is to evaluate the efficacy, safety and postoperative ocular discomfort by individually customized Photorefractive intrastromal crosslinking (PiXL) without epithelium debridement in high oxygen environment (Epi-on) for progressive Keratoconus.

Detailed description: The study is designed as a prospective, open-label, nonrandomized trial involving participants of both genders aged 18-35 years with Keratoconus planned for routine corneal crosslinking at the Department of Ophthalmology, Umeå University Hospital, Umeå, Sweden.

The study includes 30 participants with unilateral Keratoconus, receiving Epi-on PiXL in high oxygen environment (n=30). All patients are informed about the procedures before consenting to participate in the study.

At baseline, before treatment, each eye is examined with slit-lamp microscopy, subjective refraction, determination of uncorrected (UCVA), low contrast visual acuity at 2.5 percentage contrast and 10 percentage contrast and best corrected (BSCVA) visual acuities using the LogMAR fast protocol and intraocular pressure (IOP) using Goldmann applanation tonometry. Under standardized, mesopic light conditions each eye is evaluated by keratometry readings and central corneal thickness, extracted from Schemipflug camera measurements, Pentacam HR® (Oculus, Inc. Lynnwood, WA) and AS-OCT (Fourier domain OCT CASIA2, Tomey Technology and vision, Germany).

Central corneal endothelial photographs are taken with the Topcon SP-IP specular microscope (Topcon Europe B.V., Capelle a/d Ijssel, the Netherlands) and total ocular wavefront is measured with iTrace (Tracey Technologies, Inc.).

Ocular discomfort is subjectively evaluated in each eye by a specific visual analogous rating scale at 4h, 8h, 12h, 24h and thereafter daily up to 1 week postoperatively.

All the above mentioned examinations are repeated at 1, 3, 6, 12 and 24 months after treatment. At 1 day and 1 week after treatment, solely UCVA, Auto refractor measurements, slit-lamp examination are evaluated.

Eligibility criteria: Inclusion Criteria:

* Patients planned for corneal crosslinking.
* Progressive keratoconus documented with a consistent decrease of best corrected visual acuity with no other explanation, an unquestionable historical progression, or a progression documented with the Pentacam Scheimpflug camera with at least 2 of the following: progressive anterior and/or posterior corneal steepening and/or progressive corneal thinning and/or increased rate of corneal thickness change from the periphery to the center.
* A keratoconus diagnosis based on abnormal posterior elevation, abnormal corneal thickness distribution and clinical noninflammatory corneal thinning using the "Belin/Ambrósio enhanced ectasia" measurements of the Pentacam Scheimpflug camera.
* Minimum corneal thickness of 400 µm at the thinnest point before epithelial removal.
* 18-35 years of age
* No ocular abnormalities except keratoconus
* No previous ocular surgery
* No cognitive insufficiency interfering with the informed consent.

Exclusion Criteria:

* Age under 18 or over 35
* Any corneal abnormalities except keratoconus
* Pregnancy or lactation
* Previous ocular surgery
* Cognitive insufficiency

Primary outcomes:
measure: Uncorrected Distance Visual Acuity (UDVA)
timeFrame: 1, 3, 6, 12 and 24 months after treatment.
measure: Keratometry readings
timeFrame: 1, 3, 6, 12 and 24 months after treatment
Secondary outcomes:
measure: Subjective Ocular Discomfort Scores
timeFrame: 4, 8h and 1, 2, 3, 4, 5, 6 and 7 days after treatment.
measure: Manifest Refractive Spherical Equivalent (MRSE)
timeFrame: 1, 3, 6, 12 and 24 months after treatment.
measure: Corneal Endothelial cell density (ECC)
timeFrame: 12 and 24 months after treatment
measure: Best Spectacle Distance Visual Acutiy (BSCVA)
timeFrame: 1, 3, 6, 12 and 24 months after treatment.
Other outcomes:
Locations:
city: Umeå
country: Sweden
facility: Umeå University Hospital
Study officials:
affiliation: Department of Clinical Sciences/Ophthalmology, Umeå University
name: Anders Behndig
role: PRINCIPAL_INVESTIGATOR
References: