CBD Matches Codeine for Post-PRK Pain, Study Finds
Oral cannabidiol provides postoperative pain control just as effectively as a standard codeine-acetaminophen regimen following eye surgery, according to a study published in the Journal of Cataract & Refractive Surgery.
Key Clinical Takeaways:
- Oral cannabidiol (50 mg, twice daily) matched the pain control efficacy of codeine-acetaminophen (30 mg–300 mg, every 4 hours) in 35 adults undergoing bilateral sequential PRK.
- Pain scores for both treatments peaked on postoperative day two, with no significant difference found in mean or maximum pain ratings (P = .538).
- Patients taking cannabidiol reported a significantly higher incidence of mild sensory changes, particularly during their first exposure to the compound.
Researchers at the University of Florida Oaks Refractive Surgery Center evaluated 35 adult patients undergoing bilateral sequential photorefractive keratectomy. Participants received oral cannabidiol at 50 milligrams twice daily for one eye, and a standard regimen of codeine-acetaminophen up to 18 morphine milligram equivalents daily for the contralateral eye. Pain ratings under both interventions peaked on postoperative day two, showing no significant difference in mean or maximum pain scores at P = .538.
Uncorrected visual acuity improved significantly by postoperative month three, revealing equivalent clinical trajectories between the two treatments at P = .928. Quality-of-life assessments and dry eye tracking using standard indices also demonstrated comparable, expected recovery patterns across both study arms, according to the investigators.
Cannabidiol Treatment Causes More Sensory Awareness Changes
The most notable divergence between the two interventions involved localized changes in sensory awareness. The study authors stated that the most notable difference was the significantly higher incidence of sensorium changes reported by patients during the cannabidiol treatment period. Researchers defined these changes as any alteration to mental faculties or perceived changes to the five senses.
This variation was heavily influenced by treatment sequence, signaling a first-exposure phenomenon. Patients randomly assigned to receive cannabidiol for their first eye reported significantly more sensorium impacts, while patients crossing over to cannabidiol for their second eye showed no such elevation. Most of these impacts involved mild visual, vestibular, and tactile symptoms rather than true cognitive or psychotropic impairment.
Nonblinded Crossover Design Limits Study Results
Study limitations include the researchers’ inability to fully separate within-participant variance or psychological carryover effects, which remains typical of nonblinded crossover designs. The results apply strictly to the full-spectrum softgel used in the trial and cannot be generalized to simultaneous bilateral PRK, cannabidiol isolates, or topical delivery methods.
The study authors recommend that clinicians discuss this specific side effect profile with patients when using cannabidiol for post-PRK care. They also call for precise, validated tools to evaluate cognitive function or investigate topical formulations to provide localized ocular analgesia while bypassing systemic absorption. This research was supported by The Consortium for Medical Marijuana Clinical Outcomes Research based in Gainesville, Florida.
Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding any medical condition, diagnosis, or treatment plan.