Photorefractive KeratectomyPhase 2NCT05477875
Cannabinoid vs Opioid for Photorefractive Keratectomy Pain Control
A Phase 2 study testing oral cannabinoid and oral codeine/acetaminophen in people with Photorefractive Keratectomy and Myopia, run by University of Florida at 1 site in United States.
Trial summary
Photorefractive Keratectomy (PRK) is a commonly performed corneal refractive surgery but has significant post-operative pain. Pain medications after PRK are typically opioid-acetaminophen combinations. Alternatives to opioid medication are worth consideration. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Photorefractive Keratectomy, Myopia, Hyperopia
- What is being tested?
- oral cannabinoid and oral codeine/acetaminophen
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 35 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2024to 22 Jan 2025
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults older than 18 years with refractive stability for 1 year electing to have PRK surgery
- Consenting to participate
- Not meeting exclusion criteria will be included in the study population.
Who cannot join
- Patients not candidates for PRK will be excluded from the study.
- Patients taking other pain medications for concomitant medical conditions including, but not limited to tricyclic antidepressants, gabapentin and tramadol will be excluded from the study.
- Additional exclusion criteria will be known or suspected allergy or hypersensitivity to any of the routine or study medications.
- Patients completing follow up appointments at anywhere other than UF Health Ophthalmology clinic at the Oaks will not be enrolled in the study.
- Patients who are pregnant or nursing are not eligible for PRK, and such patients are not eligible to enroll in this study. Female patients of child-bearing age will be pregnancy tested before surgery and study enrollment.
- Patients will be specifically counseled, and it will be noted in the written informed consent that use of the cannabinoid product may result in a positive THC urinalysis screening test so they may self-exclude if such a situation could cause social and/or employment conflict.
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Florida Oaks Eye Center
Gainesville, Florida, 32605
About this study
Official title: Randomized, Controlled Cross-over Comparison of Cannabinoid to Oral Opioid for Postoperative Photorefractive Keratectomy Pain Control
Photorefractive Keratectomy (PRK) is a commonly performed corneal refractive surgery but has significant post-operative pain. Pain medications after PRK are typically opioid-acetaminophen combinations. Alternatives to opioid medication are worth consideration. Patients will receive PRK in each eye sequentially, using the cannabinoid or codeine/acetaminophen for one eye and the other treatment for the fellow eye two weeks later.
- Conditions
- Photorefractive Keratectomy, Myopia, Hyperopia
- Being tested
- oral cannabinoid, oral codeine/acetaminophen
- Medical subject headings
- Myopia, Hyperopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
oral cannabinoidDrug
Also called dronabinol
dronabinol
oral codeine/acetaminophenCombination product
10 tablets of acetaminophen-codeine combination (300-30mg) without refills.
| Study group | Role | What they receive |
|---|---|---|
| Oral cannabinoid | Experimental | Oral cannabinoid Receives: Drug: oral cannabinoid |
| Oral codeine/acetaminophen | Active comparator | Oral codeine-acetaminophen for controlling pain Receives: Combination Product: oral codeine/acetaminophen |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pain as Recorded by the FACES Scale (Maximum) After First Surgery
The Wong-Baker Faces Pain Rating Scale is a pain scale that was developed by Donna Wong and Connie Baker. The scale shows a series of faces ranging from a happy face at 0, or "no hurt", to a crying face at 10, which represents "hurts like the worst pain imaginable"
Measured: 1 week after first surgery
Pain as Recorded by the FACES Scale (Maximum) After Second Surgery
The Wong-Baker Faces Pain Rating Scale is a pain scale that was developed by Donna Wong and Connie Baker. The scale shows a series of faces ranging from a happy face at 0, or "no hurt", to a crying face at 10, which represents "hurts like the worst pain imaginable"
Measured: 1 week after second surgery
Secondary outcomes (5)
Uncorrected Visual Acuity of First Eye Surgery
Uncorrected visual acuity as measured by Snellen Chart
Measured: 3 months after first surgery
PROWL-SS
An online questionnaire derived from the Patient-Reported Outcomes With LASIK (PROWL) will be given to patients after PRK at 3 months. It ranges from 0-100, where 100 indicates best possible vision and satisfaction, while 0 indicates worst possible vision and satisfaction.
Measured: 3 month
Quality of Life Refractive Correction Survey
The QIRC measures quality of life associated with vision and eyewear problems, measured at 3 months. It ranges from 0-100, where 0 indicates best possible vision and quality of life and 100 indicates worst possible vision and quality of life.
Measured: 3 months
Ocular Discomfort Questionnaire
An online questionnaire derived from the Ocular Surface Disease Index (OSDI) at 3 months. It ranges from 0-48, where 0 indicates no eye discomfort and 48 indicates constant, debilitating, worst-possible eye discomfort or pain.
Measured: 3 months
Uncorrected Visual Acuity of Second Eye Surgery
Uncorrected visual acuity as measured by Snellen Chart
Measured: 3 months after second surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2022
- Study start1 Feb 2024
- Primary completion22 Jan 2025
- Study completion22 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Photorefractive KeratectomyStudies of the same condition, open and under way.
- More trials run by University of FloridaThe 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 35 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Florida
- Sponsor type
- University, hospital or other
- Collaborators
- Consortium for Medical Marijuana Clinical Outcomes Research
- Responsible party
- Sponsor
- Investigators
- W Steigleman, MD, Principal investigator, University of Florida
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05477875
- Sponsor's protocol ID
- IRB202201660 -A
- Status last verified
- Jun 2025
- First submitted
- 21 Jul 2022
- Last updated
- 7 Aug 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Zhou Y, Swiatek K, Nguyen A, Tuli S, Steigleman WA. Randomized, controlled crossover comparison of oral cannabidiol with oral opioid for postoperative PRK pain control. J Cataract Refract Surg. 2026 Jul 29. doi: 10.1097/j.jcrs.0000000000002030. Online ahead of print.
PubMed 42524865
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized, Controlled Cross-over Comparison of Cannabinoid to Oral Opioid for Postoperative Photorefractive Keratectomy Pain Control
- ClinicalTrials.gov ID
- NCT05477875
- Acronym / sponsor ID
- IRB202201660 -A
- Conditions
- Photorefractive Keratectomy, Myopia, Hyperopia
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 35 participants (actual)
- Lead sponsor
- University of FloridaUniversity, hospital or other
- Collaborators
- Consortium for Medical Marijuana Clinical Outcomes Research
- Study start
- 1 Feb 2024 (actual)
- Primary completion
- 22 Jan 2025 (actual)
- Study completion
- 22 Jan 2025 (actual)
- First posted
- 28 Jul 2022 (actual)
- Results
- Posted 7 Aug 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Photorefractive Keratectomy (PRK) is a commonly performed corneal refractive surgery but has significant post-operative pain. Pain medications after PRK are typically opioid-acetaminophen combinations. Alternatives to opioid medication are worth consideration. Patients will receive PRK in each eye sequentially, using the cannabinoid or codeine/acetaminophen for one eye and the other treatment for the fellow eye two weeks later.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Oral cannabinoid | Experimental | Drug: oral cannabinoidOral cannabinoid |
| Oral codeine/acetaminophen | Active comparator | Combination Product: oral codeine/acetaminophenOral codeine-acetaminophen for controlling pain |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Adults older than 18 years with refractive stability for 1 year electing to have PRK surgery
- Consenting to participate
- Not meeting exclusion criteria will be included in the study population.
Key exclusion criteria (6 listed)
- Patients not candidates for PRK will be excluded from the study.
- Patients taking other pain medications for concomitant medical conditions including, but not limited to tricyclic antidepressants, gabapentin and tramadol will be excluded from the study.
- Additional exclusion criteria will be known or suspected allergy or hypersensitivity to any of the routine or study medications.
- Patients completing follow up appointments at anywhere other than UF Health Ophthalmology clinic at the Oaks will not be enrolled in the study.
- Patients who are pregnant or nursing are not eligible for PRK, and such patients are not eligible to enroll in this study. Female patients of child-bearing age will be pregnancy tested before surgery and study enrollment.
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 |
|---|---|---|
| oral cannabinoidAlso: dronabinoldronabinol | Drug | Oral cannabinoid |
| oral codeine/acetaminophen10 tablets of acetaminophen-codeine combination (300-30mg) without refills. | Combination product | Oral codeine/acetaminophen |
Primary outcome
Pain as Recorded by the FACES Scale (Maximum) After First Surgery
Time frame: 1 week after first surgery
The Wong-Baker Faces Pain Rating Scale is a pain scale that was developed by Donna Wong and Connie Baker. The scale shows a series of faces ranging from a happy face at 0, or "no hurt", to a crying face at 10, which represents "hurts like the worst pain imaginable"
Pain as Recorded by the FACES Scale (Maximum) After Second Surgery
Time frame: 1 week after second surgery
The Wong-Baker Faces Pain Rating Scale is a pain scale that was developed by Donna Wong and Connie Baker. The scale shows a series of faces ranging from a happy face at 0, or "no hurt", to a crying face at 10, which represents "hurts like the worst pain imaginable"
5 secondary outcomes
Uncorrected Visual Acuity of First Eye Surgery
Time frame: 3 months after first surgery
PROWL-SS
Time frame: 3 month
Quality of Life Refractive Correction Survey
Time frame: 3 months
Ocular Discomfort Questionnaire
Time frame: 3 months
Uncorrected Visual Acuity of Second Eye Surgery
Time frame: 3 months after second surgery
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Aug 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 42524865Zhou Y, Swiatek K, Nguyen A, Tuli S, Steigleman WA. Randomized, controlled crossover comparison of oral cannabidiol with oral opioid for postoperative PRK pain control. J Cataract Refract Surg. 2026 Jul 29. doi: 10.1097/j.jcrs.0000000000002030. Online ahead of print.
- Individual participant dataSharing planned: No
Related trials for Photorefractive Keratectomy
Active, not recruitingObservational study
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Comparison of Ketorolac Tromethamine 0.5%-Soaked Bandage Contact Lenses Versus Non-Medicated Bandage Contact Lenses on Postoperative Pain Control After Photorefractive Keratectomy
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Analysis of The Outcomes of Therapeutic Photorefractive Keratectomy Combined With Prophylactic Accelerated Cross-Linking (PRK-Plus), for Treatment of Thin Suspicious Cornea
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CONTOURA vs WFO Ablation PRK & LASIK
Refractive Surgery
Not yet recruiting
Effectiveness and Safety of the TENEO 317 Model 2 Excimer Laser to Treat Myopia With or Without Astigmatism by Transepithelial Photorefractive Keratectomy
Myopia
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.
W Steigleman, MD principal investigator
University of Florida
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing oral cannabinoid and oral codeine/acetaminophen in people with Photorefractive Keratectomy and Myopia, run by University of Florida at 1 site in United States.
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 3 inclusion and 6 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 7 Aug 2025. 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 United States. 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.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 7 Aug 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
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?
Pain as Recorded by the FACES Scale (Maximum) After First Surgery (time frame: 1 week after first surgery). 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?
On the ClinicalTrials.gov record for NCT05477875, which also lists 1 linked publication.
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 7 Aug 2025.