MyopiaNCT04663048
PiXL as a Treatment for Low Grade Myopia
A study testing PiXL in people with Myopia and Refractive Errors, run by Umeå University at 1 site in Sweden.
Trial summary
To assess the improvement in myopia with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on) in high oxygen environment for low grade myopia. The study compares two 3.5-mm central ring-shaped zone protocols; 10 min illumination time vs 16:40 min illumination time. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Myopia, Refractive Errors
- 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
- 26 participants
- Where
- 1 siteSweden
- Study dates
- 7 Feb 2019to 17 Jun 2024
- 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 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.
About this study
Official title: Evaluation of a Reduced Photorefractive Intrastromal Corneal Crosslinking Illumination Protocol. A Randomized Controlled Trial.
To assess the improvement in myopia with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on) in high oxygen environment for low grade myopia. The study compares two 3.5-mm central ring-shaped zone protocols; 10 min illumination time vs 16:40 min illumination time.
Read the detailed description
The study design is a prospective, single-masked intraindividually comparing randomized controlled trial, conducted at the Department of Clinical Sciences / Ophthalmology, Umeå University Hospital, Umeå, Sweden. The study includes healthy men and women with low grade myopia, aged between 18-35 years and involves 25 participants with a myopia of -0.50 to -2.5 diopters (D) and astigmatism of ≤0.75D. All participants are treated with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on), after topical riboflavin. Both eyes are treated and 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. Throughout the treatment, humidified oxygen is continuously delivered around the eye using an oxygen mask to achieve an oxygen concentration of ≥95 percentage. Prior to inclusion all participants are informed about the procedures and provide oral and written informed consent.
At baseline, each eye is examined with slit-lamp microscopy, subjective refraction, determination of uncorrected (UCVA), low contrast visual acuity at 2.5 percentage 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, central corneal thickness and after treatment also the depth of demarcation lines, extracted from Schemipflug camera measurements, Pentacam HR® (Oculus, Inc. Lynnwood, WA). Central corneal endothelial photographs are taken with the Topcon SP-2000P specular microscope (Topcon Europe B.V., Capelle a/d Ijssel, the Netherlands), from which the corneal endothelial cell count is manually calculated from a cluster of 25 cells from each photograph. Total ocular wavefront is measured with iTrace (Tracey Technologies, Inc.).
All the above mentioned examinations are reassessed at 1, 3, 6 and 12 months after treatment. At 1 day and 1 week after treatment, solely UCVA, Auto refractor measurements, slit-lamp examination and a subjective comparison of discomfort and visual performance in each eye are evaluated.
- Conditions
- Myopia, Refractive Errors
- Being tested
- PiXL
- Keywords
- Corneal Crosslinking
- Medical subject headings
- Myopia, Refractive Errors
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 low grade myopia.
| Study group | Role | What they receive |
|---|---|---|
| Protocol A | Experimental | PiXL treatment with pulsed UV illumination (1.0 sec on /0.8 sec off) in high oxygen in a central ring-shaped 3.5-mm zone of the cornea and total illumination time of 10 min. The area consist of three rings with a central 1.5-mm zone that is left untreated. The illumination area consists of three rings, where the outer and inner ring are thinner than the middle ring. The maximum energy is distributed in the middle ring. Receives: Procedure: PiXL |
| Protocol B | Active comparator | PiXL treatment with pulsed (0.5 sec on / 1 sec off) UV illumination in high oxygen in a central ring-shaped 3.5-mm zone of the cornea and total illumination time of 16:40 min. The area consist of three rings with a central 1.5-mm zone that is left untreated. The illumination area consists of three rings, where the outer and inner ring are thinner than the middle ring. The maximum energy is distributed in the middle ring. Receives: Procedure: PiXL |
What is being measured
The primary outcome is the main question the study is designed to answer.
Uncorrected distance visual acuity (UDVA)
Change from baseline in UDVA (logMAR)
Measured: 1, 3, 6 and 12 months after treatment.
Manifest Refractive Spherical Equivalent
Change from baseline in MRSE (Diopters)
Measured: 1, 3, 6 and 12 months after treatment
Secondary outcomes (3)
Best spectacle corrected visual acuity (BSCVA)
Change from baseline in BSCVA (logMAR)
Measured: 1, 3, 6 and 12 months after treatment
Endothelial cell density (ECC)
Change from baseline in ECC (cells/mm^2)
Measured: 1, 3, 6 and 12 months after treatment
Low contrast visual acuity at 10% and 2.5% (LCVA)
Change from baseline in LCVA 10 % and 2.5% (logMAR)
Measured: 1, 3, 6 and 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 posted10 Dec 2020
- Study start7 Feb 2019
- Primary completion17 Jun 2024 (estimated)
- Study completion17 Jun 2024 (estimated)
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.
- More trials run by Umeå UniversityThe sponsor's other registered studies.
- 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
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 26 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, University Hospital, Umeå
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04663048
- Sponsor's protocol ID
- PiXLMYOP-III
- Status last verified
- Dec 2023
- First submitted
- 9 Dec 2020
- Last updated
- 20 Dec 2023
- 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 20 Dec 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of a Reduced Photorefractive Intrastromal Corneal Crosslinking Illumination Protocol. A Randomized Controlled Trial.
- ClinicalTrials.gov ID
- NCT04663048
- Acronym / sponsor ID
- PiXLMYOP-III
- Conditions
- Myopia, Refractive Errors
- Keywords
- Corneal Crosslinking
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 26 participants (actual)
- Lead sponsor
- Umeå UniversityUniversity, hospital or other
- Collaborators
- Glaukos Corporation
- Study start
- 7 Feb 2019 (actual)
- Primary completion
- 17 Jun 2024 (estimated)
- Study completion
- 17 Jun 2024 (estimated)
- First posted
- 10 Dec 2020 (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 assess the improvement in myopia with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on) in high oxygen environment for low grade myopia. The study compares two 3.5-mm central ring-shaped zone protocols; 10 min illumination time vs 16:40 min illumination time.
Detailed description
The study design is a prospective, single-masked intraindividually comparing randomized controlled trial, conducted at the Department of Clinical Sciences / Ophthalmology, Umeå University Hospital, Umeå, Sweden. The study includes healthy men and women with low grade myopia, aged between 18-35 years and involves 25 participants with a myopia of -0.50 to -2.5 diopters (D) and astigmatism of ≤0.75D. All participants are treated with phototherapeutic intrastromal corneal collagen cross-linking (PiXL) without epithelial debridement (epi-on), after topical riboflavin. Both eyes are treated and 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. Throughout the treatment, humidified oxygen is continuously delivered around the eye using an oxygen mask to achieve an oxygen concentration of ≥95 percentage. Prior to inclusion all participants are informed about the procedures and provide oral and written informed consent.
At baseline, each eye is examined with slit-lamp microscopy, subjective refraction, determination of uncorrected (UCVA), low contrast visual acuity at 2.5 percentage 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, central corneal thickness and after treatment also the depth of demarcation lines, extracted from Schemipflug camera measurements, Pentacam HR® (Oculus, Inc. Lynnwood, WA). Central corneal endothelial photographs are taken with the Topcon SP-2000P specular microscope (Topcon Europe B.V., Capelle a/d Ijssel, the Netherlands), from which the corneal endothelial cell count is manually calculated from a cluster of 25 cells from each photograph. Total ocular wavefront is measured with iTrace (Tracey Technologies, Inc.).
All the above mentioned examinations are reassessed at 1, 3, 6 and 12 months after treatment. At 1 day and 1 week after treatment, solely UCVA, Auto refractor measurements, slit-lamp examination and a subjective comparison of discomfort and visual performance in each eye are evaluated.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Protocol A | Experimental | Procedure: PiXLPiXL treatment with pulsed UV illumination (1.0 sec on /0.8 sec off) in high oxygen in a central ring-shaped 3.5-mm zone of the cornea and total illumination time of 10 min. The area consist of three rings with a central 1.5-mm zone that is left untreated. The illumination area consists of three rings, where the outer and inner ring are thinner than the middle ring. The maximum energy is distributed in the middle ring. |
| Protocol B | Active comparator | Procedure: PiXLPiXL treatment with pulsed (0.5 sec on / 1 sec off) UV illumination in high oxygen in a central ring-shaped 3.5-mm zone of the cornea and total illumination time of 16:40 min. The area consist of three rings with a central 1.5-mm zone that is left untreated. The illumination area consists of three rings, where the outer and inner ring are thinner than the middle ring. The maximum energy is distributed in the middle ring. |
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 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 low grade myopia. | Procedure or surgery | Protocol A, Protocol B |
Primary outcome
Uncorrected distance visual acuity (UDVA)
Time frame: 1, 3, 6 and 12 months after treatment.
Change from baseline in UDVA (logMAR)
Manifest Refractive Spherical Equivalent
Time frame: 1, 3, 6 and 12 months after treatment
Change from baseline in MRSE (Diopters)
3 secondary outcomes
Best spectacle corrected visual acuity (BSCVA)
Time frame: 1, 3, 6 and 12 months after treatment
Endothelial cell density (ECC)
Time frame: 1, 3, 6 and 12 months after treatment
Low contrast visual acuity at 10% and 2.5% (LCVA)
Time frame: 1, 3, 6 and 12 months after treatment
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Dec 2023.
- 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
University Hospital, Umeå
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 Refractive Errors, 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: status not confirmed, as of the sponsor's last update on 20 Dec 2023. 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?
Results are not available in the source record.
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?
Uncorrected distance visual acuity (UDVA) (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 20 Dec 2023.