Cannabidiol vs Opioid for Photorefractive Keratectomy Pain Control

University of Florida (Other)
Overall Status
Not yet recruiting ID
Consortium for Medical Marijuana Clinical Outcomes Research (Other)

Study Details

Study Description

Brief 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. Patients will receive PRK in each eye sequentially, using the CBD chemovar or codeine/acetaminophen for one eye and the other treatment for the fellow eye two weeks later.

Condition or Disease Intervention/Treatment Phase
  • Drug: oral CBD
  • Combination Product: oral codeine/acetaminophen
Phase 2

Study Design

Study Type:
Anticipated Enrollment :
35 participants
Intervention Model:
Crossover Assignment
None (Open Label)
Primary Purpose:
Official Title:
Randomized, Controlled Cross-over Comparison of Cannabidiol to Oral Opioid for Postoperative Photorefractive Keratectomy Pain Control
Anticipated Study Start Date :
Sep 1, 2022
Anticipated Primary Completion Date :
Sep 1, 2024
Anticipated Study Completion Date :
Sep 1, 2024

Arms and Interventions

Arm Intervention/Treatment
Experimental: Oral CBD

Oral softgel containing cannabidiol (CBD) extract

Drug: oral CBD
Cannabidiol 15mg softgel (less than 0.5mg THC)

Active Comparator: Oral codeine/acetaminophen

Oral codeine-acetaminophen for controlling pain

Combination Product: oral codeine/acetaminophen
10 tablets of acetaminophen-codeine combination (300-30mg) without refills.

Outcome Measures

Primary Outcome Measures

  1. Pain as recorded by the FACES scale [1 week]

    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"

Secondary Outcome Measures

  1. Uncorrected visual acuity [1 week]

    Uncorrected visual acuity as measured by Snellen Chart, as well as change in uncorrected visual acuity.

  2. Subjective vision questionnaire [1 week]

    An online questionnaire derived from the Ocular Surface Disease Index (OSDI) and the Patient-Reported Outcomes With LASIK (PROWL) will be given to patients after PRK. A ocular discomfort score will be calculated at one week.

  3. Corneal haze [1 week]

    Corneal haze will be recorded by slit lamp exam according to the Fantes scale, which measures degree of corneal haze after surface ablation.

  4. Ocular discomfort questionnaire [1 week]

    An online questionnaire derived from the Ocular Surface Disease Index (OSDI) and the Patient-Reported Outcomes With LASIK (PROWL) will be given to patients after PRK. A subjective vision score will be calculated at one week.

Eligibility Criteria


Ages Eligible for Study:
18 Years to 65 Years
Sexes Eligible for Study:
Accepts Healthy Volunteers:
Inclusion Criteria:
  • 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.

Exclusion Criteria:
  • 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 CBD 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.

Contacts and Locations


No locations specified.

Sponsors and Collaborators

  • University of Florida
  • Consortium for Medical Marijuana Clinical Outcomes Research


  • Principal Investigator: W Steigleman, MD, University of Florida

Study Documents (Full-Text)

None provided.

More Information


None provided.
Responsible Party:
University of Florida Identifier:
Other Study ID Numbers:
  • IRB202201660 -A
First Posted:
Jul 28, 2022
Last Update Posted:
Jul 28, 2022
Last Verified:
Jul 1, 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD:
Studies a U.S. FDA-regulated Drug Product:
Studies a U.S. FDA-regulated Device Product:
Product Manufactured in and Exported from the U.S.:
Additional relevant MeSH terms:

Study Results

No Results Posted as of Jul 28, 2022