MyopiaPiXLO2NCT03197272
Advanced Cross Linking for Low-grade Myopia
A study testing PiXL in people with Myopia and Corneal Crosslinking, run by Umeå University at 1 site in Sweden.
Trial summary
To evaluate the improvement in myopic refractive error and the corneal endothelial safety with a corneal crosslinking treatment regimen for mild myopia. The treatment involves a 4-mm central treatment zone in high oxygen environment without corneal epithelial debridement. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Myopia, Corneal Crosslinking
- What is being tested?
- PiXL
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 23 participants
- Where
- 1 siteSweden
- Study dates
- 21 Apr 2016to 30 Nov 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Spherical equivalent on distance subjective refraction between -0.50D and -2.50D.
- Astigmatism ≤ 0.75D
- Stable myopia. Maximum change in refraction of 0.50D in the last 2 years.
- Best corrected visual acuity of at least 0.00 logMAR (ETDRS chart).
- Thinnest pachymetry reading ≥ 440 μm.
- No previous ocular surgery.
- No cognitive insufficiency interfering with the informed consent.
Who cannot join
- History of or current ocular condition, disease, surgery or medication with ocular effects that could affect the outcomes of the treatment.
- Allergy to any substance or device used in the study.
- Cognitive insufficiency interfering with the informed consent.
Trial locations and contacts
1 site in 1 country.
Sweden1 site
Department of Clinical Sciences/Ophthalmology, Umeå University
Umeå, 901 85
About this study
Official title: Non-invasive Phototherapeutic Intrastromal Corneal Collagen Crosslinking (PiXL) for Low-grade Myopia
To evaluate the improvement in myopic refractive error and the corneal endothelial safety with a corneal crosslinking treatment regimen for mild myopia. The treatment involves a 4-mm central treatment zone in high oxygen environment without corneal epithelial debridement.
Read the detailed description
The study is designed as a prospective, single-masked intraindividually comparing randomized controlled trial involving healthy volunteers ≥18 years of age of both genders with mild myopia, performed at the Department of Clinical Sciences / Ophthalmology, Umeå University Hospital, Umeå, Sweden. The study involves 23 persons with a myopia of -0.5 to -2.5 diopters (D) and astigmatism of ≤0.75 D. All participants are treated with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on), after topical riboflavin. For myopia of less than 1.0D, 10 J/cm2 will be used, for higher levels of myopia 15J/cm2 will be used, and the treatment involves continuous delivery of oxygen around the eye using an oxygen mask to achieve an oxygen concentration of ≥90% during treatment. Participants will be randomized to receive ultraviolet (UV) light according to PiXL Protocol A in one eye and PiXL Protocol B in the other, which is masked to the participant. Both eyes will be treated during the same visit.
Protocol A: UV irradiation in a central 4 mm homogenous zone of the cornea. Protocol B: UV irradiation in a central ring-shaped 4 mm area of the cornea. Patients are randomized utilizing a computer list of unique random numbers between 1 and 23; an even number will be treated with a homogeneous zone in the right eye; an uneven number with a homogeneous zone in the left eye. All patients are informed about the procedures and provide oral and written consent before inclusion in the study.
At baseline, before treatment, each eye is evaluated with slit-lamp examination, subjective refraction, determination of uncorrected (UCVA) and best corrected (BSCVA) visual acuities using the LogMAR fast protocol and intraocular pressure (IOP) using Goldmann applanation tonometry. Each eye is photographed using the "25 pictures" program with the Pentacam HR® (Oculus, Inc. Lynnwood, WA) under standardized, mesopic light conditions. Keratometry readings, central corneal thickness and the average corneal densitometry values (corneal light backscatter), expressed as standardized gray scale units, GSU) is determined with the Pentacam HR®. Central corneal endothelial photographs are taken with the Topcon SP-2000P specular microscope (Topcon Europe B.V., Capelle a/d Ijssel, the Netherlands), and the corneal endothelial cell count is calculated from a cluster of 25 cells from each photograph.
All the above mentioned investigations are repeated at 1, 3, 6,12 and 24 months after the treatment. At 1 week after treatment, UCVA is registered and a slit-lamp examination, a subjective comparison of discomfort and visual performance in each eye and an autorefractometer measurement are performed. One day after treatment the latter 3 examinations are performed.
- Conditions
- Myopia, Corneal Crosslinking
- Being tested
- PiXL
- Keywords
- Myopia, corneal Crosslinking
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PiXLProcedure or surgery
Phototherapeutic intrastromal corneal collagen cross-linking (PiXL) performed in a high-oxygen environment without corneal epithelial debridement, for treatment of mild myopia.
| Study group | Role | What they receive |
|---|---|---|
| PiXL Protocol A | Experimental | PiXL treatment with UV irradiation in a central 4 mm homogenous zone of the cornea. For myopia of less than 1.0D, 10 J/cm2 will be used, for higher levels of myopia 15J/cm2 will be used. Receives: Procedure: PiXL |
| PiXL Protocol B | Active comparator | PiXL treatment with UV irradiation in a central ring-shaped 4-mm area of the cornea. A central 2-mm zone is left untreated, and the energy is higher towards the periphery of the ring-shaped area, reaching its maximum at 2 mm from the corneal centre. For myopia of less than 1.0D, a maximum of 10 J/cm2 will be used, for higher levels of myopia a maximum of 15J/cm2 will be used. Receives: Procedure: PiXL |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline in uncorrected visual acuity
Change from baseline in distance uncorrected visual acuity
Measured: 1, 3, 6 and 12 months after treatment
Change from baseline in spherical equivalent
Change from baseline in spherical equivalent on subjective distance refraction
Measured: 1, 3, 6 and 12 months after treatment
Secondary outcomes (1)
Change from baseline in corneal endothelial cell density
Change from baseline in central corneal endothelial cell density
Measured: 12 months after treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jun 2017
- Study start21 Apr 2016
- Primary completion31 Oct 2020
- Study completion30 Nov 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MyopiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Model description
- Prospective, single-masked intraindividually comparing randomized controlled trial. Participants will be randomized to receive ultraviolet (UV) light according to protocol A in one eye and protocol B in the other, which is masked to the participant. Both eyes will be treated during the same visit. Protocol A: UV irradiation in a central 4 mm homogenous zone of the cornea. Protocol B: UV irradiation in a central ring-shaped 4 mm area of the cornea. Patients are randomized utilizing a computer list of unique random numbers between 1 and 23; an even number will be treated with a homogeneous zone in the right eye; an uneven number with a homogeneous zone in the left eye.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 23 participants (actual)
Sponsor and investigators
- Lead sponsor
- Umeå University
- Sponsor type
- University, hospital or other
- Collaborators
- Glaukos Corporation
- Responsible party
- Sponsor
- Investigators
- Anders Behndig, MD, PhD, Principal investigator, Department of Clinical Sciences/Ophthalmology, Umeå University, Umeå, Sweden
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03197272
- Sponsor's protocol ID
- PiXLMYOP-I
- Acronym
- PiXLO2
- Status last verified
- Dec 2020
- First submitted
- 20 Jun 2017
- Last updated
- 11 Dec 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Dec 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Non-invasive Phototherapeutic Intrastromal Corneal Collagen Crosslinking (PiXL) for Low-grade Myopia
- ClinicalTrials.gov ID
- NCT03197272
- Acronym / sponsor ID
- PiXLO2 / PiXLMYOP-I
- Conditions
- Myopia, Corneal Crosslinking
- Keywords
- Myopia, corneal Crosslinking
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 23 participants (actual)
- Lead sponsor
- Umeå UniversityUniversity, hospital or other
- Collaborators
- Glaukos Corporation
- Study start
- 21 Apr 2016 (actual)
- Primary completion
- 31 Oct 2020 (actual)
- Study completion
- 30 Nov 2020 (actual)
- First posted
- 23 Jun 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To evaluate the improvement in myopic refractive error and the corneal endothelial safety with a corneal crosslinking treatment regimen for mild myopia. The treatment involves a 4-mm central treatment zone in high oxygen environment without corneal epithelial debridement.
Detailed description
The study is designed as a prospective, single-masked intraindividually comparing randomized controlled trial involving healthy volunteers ≥18 years of age of both genders with mild myopia, performed at the Department of Clinical Sciences / Ophthalmology, Umeå University Hospital, Umeå, Sweden. The study involves 23 persons with a myopia of -0.5 to -2.5 diopters (D) and astigmatism of ≤0.75 D. All participants are treated with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on), after topical riboflavin. For myopia of less than 1.0D, 10 J/cm2 will be used, for higher levels of myopia 15J/cm2 will be used, and the treatment involves continuous delivery of oxygen around the eye using an oxygen mask to achieve an oxygen concentration of ≥90% during treatment. Participants will be randomized to receive ultraviolet (UV) light according to PiXL Protocol A in one eye and PiXL Protocol B in the other, which is masked to the participant. Both eyes will be treated during the same visit.
Protocol A: UV irradiation in a central 4 mm homogenous zone of the cornea. Protocol B: UV irradiation in a central ring-shaped 4 mm area of the cornea. Patients are randomized utilizing a computer list of unique random numbers between 1 and 23; an even number will be treated with a homogeneous zone in the right eye; an uneven number with a homogeneous zone in the left eye. All patients are informed about the procedures and provide oral and written consent before inclusion in the study.
At baseline, before treatment, each eye is evaluated with slit-lamp examination, subjective refraction, determination of uncorrected (UCVA) and best corrected (BSCVA) visual acuities using the LogMAR fast protocol and intraocular pressure (IOP) using Goldmann applanation tonometry. Each eye is photographed using the "25 pictures" program with the Pentacam HR® (Oculus, Inc. Lynnwood, WA) under standardized, mesopic light conditions. Keratometry readings, central corneal thickness and the average corneal densitometry values (corneal light backscatter), expressed as standardized gray scale units, GSU) is determined with the Pentacam HR®. Central corneal endothelial photographs are taken with the Topcon SP-2000P specular microscope (Topcon Europe B.V., Capelle a/d Ijssel, the Netherlands), and the corneal endothelial cell count is calculated from a cluster of 25 cells from each photograph.
All the above mentioned investigations are repeated at 1, 3, 6,12 and 24 months after the treatment. At 1 week after treatment, UCVA is registered and a slit-lamp examination, a subjective comparison of discomfort and visual performance in each eye and an autorefractometer measurement are performed. One day after treatment the latter 3 examinations are performed.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- Single blind (participant)
- Number of arms
- 2
- Model description
- Prospective, single-masked intraindividually comparing randomized controlled trial. Participants will be randomized to receive ultraviolet (UV) light according to protocol A in one eye and protocol B in the other, which is masked to the participant. Both eyes will be treated during the same visit. Protocol A: UV irradiation in a central 4 mm homogenous zone of the cornea. Protocol B: UV irradiation in a central ring-shaped 4 mm area of the cornea. Patients are randomized utilizing a computer list of unique random numbers between 1 and 23; an even number will be treated with a homogeneous zone in the right eye; an uneven number with a homogeneous zone in the left eye.
| Arm | Type | Receives |
|---|---|---|
| PiXL Protocol A | Experimental | Procedure: PiXLPiXL treatment with UV irradiation in a central 4 mm homogenous zone of the cornea. For myopia of less than 1.0D, 10 J/cm2 will be used, for higher levels of myopia 15J/cm2 will be used. |
| PiXL Protocol B | Active comparator | Procedure: PiXLPiXL treatment with UV irradiation in a central ring-shaped 4-mm area of the cornea. A central 2-mm zone is left untreated, and the energy is higher towards the periphery of the ring-shaped area, reaching its maximum at 2 mm from the corneal centre. For myopia of less than 1.0D, a maximum of 10 J/cm2 will be used, for higher levels of myopia a maximum of 15J/cm2 will be used. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Spherical equivalent on distance subjective refraction between -0.50D and -2.50D.
- Astigmatism ≤ 0.75D
- Stable myopia. Maximum change in refraction of 0.50D in the last 2 years.
- Best corrected visual acuity of at least 0.00 logMAR (ETDRS chart).
- Thinnest pachymetry reading ≥ 440 μm.
Key exclusion criteria (3 listed)
- History of or current ocular condition, disease, surgery or medication with ocular effects that could affect the outcomes of the treatment.
- Allergy to any substance or device used in the study.
- Cognitive insufficiency interfering with the informed consent.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PiXLPhototherapeutic intrastromal corneal collagen cross-linking (PiXL) performed in a high-oxygen environment without corneal epithelial debridement, for treatment of mild myopia. | Procedure or surgery | PiXL Protocol A, PiXL Protocol B |
Primary outcome
Change from baseline in uncorrected visual acuity
Time frame: 1, 3, 6 and 12 months after treatment
Change from baseline in distance uncorrected visual acuity
Change from baseline in spherical equivalent
Time frame: 1, 3, 6 and 12 months after treatment
Change from baseline in spherical equivalent on subjective distance refraction
1 secondary outcome
Change from baseline in corneal endothelial cell density
Time frame: 12 months after treatment
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Dec 2020.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Anders Behndig, MD, PhD principal investigator
Department of Clinical Sciences/Ophthalmology, Umeå University, Umeå, Sweden
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing PiXL in people with Myopia and Corneal Crosslinking, run by Umeå University at 1 site in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Dec 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline in uncorrected visual acuity (time frame: 1, 3, 6 and 12 months after treatment). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Dec 2020.