Trial Outcomes & Findings for Cannabinoid vs Opioid for Photorefractive Keratectomy Pain Control (NCT NCT05477875)
NCT ID: NCT05477875
Last Updated: 2025-08-07
Results Overview
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"
COMPLETED
PHASE2
35 participants
1 week after first surgery
2025-08-07
Participant Flow
Thirty-five myopic patients were recruited and had surgery for both eyes completed between 1/1/2024 and 12/31/2024. Patients seeking refractive surgery and who were candidates for photorefractive keratectomy were approached with the option to enroll in the ophthalmology clinic.
Any patient who could not undergo surgery due to contraindications such as thin cornea, irregular astigmatism, or inability to lay flat were excluded. Patients who could not undergo sequential eye surgery due to scheduling constraints could not enroll in the study.
Participant milestones
| Measure |
Group 1
Group 1 patients were assigned to take CBD 50mg 2x/day by mouth for 1 week after surgery on the first eye and Tylenol T3 30-300mg 3x/day by mouth for 1 week after surgery on the fellow eye.
|
Group 2
Group 2 patients were assigned to take Tylenol T3 30-300mg 3x/day by mouth for 1 week after surgery on the first eye and CBD 50mg 2x/day by mouth for 1 week after surgery on the fellow eye.
|
|---|---|---|
|
Preoperative
STARTED
|
16
|
19
|
|
Preoperative
COMPLETED
|
16
|
19
|
|
Preoperative
NOT COMPLETED
|
0
|
0
|
|
POW1
STARTED
|
16
|
19
|
|
POW1
COMPLETED
|
16
|
19
|
|
POW1
NOT COMPLETED
|
0
|
0
|
|
POM1
STARTED
|
16
|
19
|
|
POM1
COMPLETED
|
16
|
19
|
|
POM1
NOT COMPLETED
|
0
|
0
|
|
POM3
STARTED
|
16
|
19
|
|
POM3
COMPLETED
|
16
|
19
|
|
POM3
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Crossover study, so participants were their own controls.
Baseline characteristics by cohort
| Measure |
Group 1
n=16 Participants
Group 1 patients had 50mg CBD chemovar twice a day by mouth after their first photorefractive surgery on one eye, then later had Tylenol T3 30-300mg three times a day by mouth after their second surgery on the fellow eye.
|
Group 2
n=19 Participants
Group 2 patients had Tylenol T3 30-300mg three times a day by mouth after their first photorefractive surgery on one eye, then later had 50mg CBD chemovar twice a day by mouth after their second surgery on the fellow eye.
|
Total
n=35 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
34.2 Years
STANDARD_DEVIATION 5.2 • n=5 Participants
|
30.6 Years
STANDARD_DEVIATION 6.8 • n=7 Participants
|
32.5 Years
STANDARD_DEVIATION 6.3 • n=5 Participants
|
|
Sex: Female, Male
Female
|
9 Participants
n=5 Participants
|
10 Participants
n=7 Participants
|
19 Participants
n=5 Participants
|
|
Sex: Female, Male
Male
|
7 Participants
n=5 Participants
|
9 Participants
n=7 Participants
|
16 Participants
n=5 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Black or African American
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
White
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=5 Participants
|
0 Participants
n=7 Participants
|
0 Participants
n=5 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
16 Participants
n=5 Participants
|
19 Participants
n=7 Participants
|
35 Participants
n=5 Participants
|
|
Visual Acuity
without glasses or contacts
|
1.109 LogMAR
STANDARD_DEVIATION 0.452 • n=5 Participants • Crossover study, so participants were their own controls.
|
1.290 LogMAR
STANDARD_DEVIATION 0.475 • n=7 Participants • Crossover study, so participants were their own controls.
|
1.207 LogMAR
STANDARD_DEVIATION 0.470 • n=5 Participants • Crossover study, so participants were their own controls.
|
|
Visual Acuity
With glasses or contacts
|
-0.062 LogMAR
STANDARD_DEVIATION 0.085 • n=5 Participants • Crossover study, so participants were their own controls.
|
0.026 LogMAR
STANDARD_DEVIATION 0.338 • n=7 Participants • Crossover study, so participants were their own controls.
|
-0.014 LogMAR
STANDARD_DEVIATION 0.257 • n=5 Participants • Crossover study, so participants were their own controls.
|
PRIMARY outcome
Timeframe: 1 week after first surgeryThe 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"
Outcome measures
| Measure |
Cannabidiol
n=16 Participants
Patients given 50mg CBD chemovar twice a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
Tylenol T3
n=19 Participants
Patients given Tylenol T3 30-300mg three times a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
|---|---|---|
|
Pain as Recorded by the FACES Scale (Maximum) After First Surgery
|
1.33 units on a scale
Standard Deviation 0.95
|
1.27 units on a scale
Standard Deviation 0.89
|
PRIMARY outcome
Timeframe: 1 week after second surgeryThe 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"
Outcome measures
| Measure |
Cannabidiol
n=19 Participants
Patients given 50mg CBD chemovar twice a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
Tylenol T3
n=16 Participants
Patients given Tylenol T3 30-300mg three times a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
|---|---|---|
|
Pain as Recorded by the FACES Scale (Maximum) After Second Surgery
|
1.46 units on a scale
Standard Deviation 0.82
|
1.79 units on a scale
Standard Deviation 1.12
|
SECONDARY outcome
Timeframe: 3 months after first surgeryUncorrected visual acuity as measured by Snellen Chart
Outcome measures
| Measure |
Cannabidiol
n=16 Participants
Patients given 50mg CBD chemovar twice a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
Tylenol T3
n=19 Participants
Patients given Tylenol T3 30-300mg three times a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
|---|---|---|
|
Uncorrected Visual Acuity of First Eye Surgery
|
-0.123 LogMAR
Standard Deviation 0.119
|
-0.054 LogMAR
Standard Deviation 0.169
|
SECONDARY outcome
Timeframe: 3 monthPopulation: Surveys assess overall quality of life which cannot be specifically attributed to a single eye since vision is binocular. For example, having excellent vision in one eye and poor vision in the other can be more disturbing than having poor vision in both eyes or cause patients to suffer from double vision. Because all survey measurements are implied to be binocular at 3 months after both surgeries are done, results are displayed by group instead of intervention. There is no separate measurement.
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.
Outcome measures
| Measure |
Cannabidiol
n=16 Participants
Patients given 50mg CBD chemovar twice a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
Tylenol T3
n=19 Participants
Patients given Tylenol T3 30-300mg three times a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
|---|---|---|
|
PROWL-SS
Pre-op
|
58.0 score on a scale
Standard Deviation 20.1
|
60.9 score on a scale
Standard Deviation 18.3
|
|
PROWL-SS
Post-op Month 3
|
81.6 score on a scale
Standard Deviation 9.0
|
85.6 score on a scale
Standard Deviation 6.9
|
SECONDARY outcome
Timeframe: 3 monthsPopulation: Surveys assess overall quality of life which cannot be specifically attributed to a single eye since vision is binocular. For example, having excellent vision in one eye and poor vision in the other can be more disturbing than having poor vision in both eyes or cause patients to suffer from double vision. Because all survey measurements are implied to be binocular at 3 months after both surgeries are done, results are displayed by group instead of intervention. There is no separate measurement.
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.
Outcome measures
| Measure |
Cannabidiol
n=16 Participants
Patients given 50mg CBD chemovar twice a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
Tylenol T3
n=19 Participants
Patients given Tylenol T3 30-300mg three times a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
|---|---|---|
|
Quality of Life Refractive Correction Survey
Pre-op
|
37.7 score on a scale
Standard Deviation 6.2
|
37.6 score on a scale
Standard Deviation 10.6
|
|
Quality of Life Refractive Correction Survey
Post-op Month 3
|
19.2 score on a scale
Standard Deviation 6.0
|
26.4 score on a scale
Standard Deviation 6.3
|
SECONDARY outcome
Timeframe: 3 monthsPopulation: Surveys assess overall quality of life which cannot be specifically attributed to a single eye since vision is binocular. For example, having excellent vision in one eye and poor vision in the other can be more disturbing than having poor vision in both eyes or cause patients to suffer from double vision. Because all survey measurements are implied to be binocular at 3 months after both surgeries are done, results are displayed by group instead of intervention. There is no separate measurement.
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.
Outcome measures
| Measure |
Cannabidiol
n=16 Participants
Patients given 50mg CBD chemovar twice a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
Tylenol T3
n=19 Participants
Patients given Tylenol T3 30-300mg three times a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
|---|---|---|
|
Ocular Discomfort Questionnaire
Pre-op
|
4.9 score on a scale
Standard Deviation 5.7
|
4.8 score on a scale
Standard Deviation 5.4
|
|
Ocular Discomfort Questionnaire
Post-op Month 3
|
4.9 score on a scale
Standard Deviation 4.8
|
3.9 score on a scale
Standard Deviation 4.0
|
SECONDARY outcome
Timeframe: 3 months after second surgeryUncorrected visual acuity as measured by Snellen Chart
Outcome measures
| Measure |
Cannabidiol
n=19 Participants
Patients given 50mg CBD chemovar twice a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
Tylenol T3
n=16 Participants
Patients given Tylenol T3 30-300mg three times a day by mouth after photorefractive surgery on one eye. Depending on study group, this may be after the first or second surgery.
|
|---|---|---|
|
Uncorrected Visual Acuity of Second Eye Surgery
|
-0.051 LogMAR
Standard Deviation 0.16
|
-0.075 LogMAR
Standard Deviation 0.121
|
Adverse Events
Cannabidiol
Tylenol T3
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place