Clinical Trial: CBD Provided Pain Relief Comparable to Codeine-Acetaminophen After Laser Eye Surgery
- Oral cannabidiol (CBD) provided pain relief comparable to codeine-acetaminophen in a randomized crossover trial involving 35 adults undergoing photorefractive keratectomy (PRK) eye surgery.
- Participants received 50 mg of low-THC oral CBD twice daily after one procedure and codeine-acetaminophen (30 mg codeine/300 mg acetaminophen) after the other, allowing direct within-subject comparison.
- No significant differences were found in pain levels, visual acuity improvement, or patient-reported outcomes between CBD and codeine-acetaminophen; both showed peak pain on day two post-surgery.
- Researchers noted mild first-exposure subjective effects from CBD but concluded that low-THC oral CBD is a potentially viable opioid-sparing pain management alternative for refractive surgery, with further larger studies needed.
Oral cannabidiol (CBD) provided pain relief comparable to codeine-acetaminophen following laser eye surgery, according to a randomized clinical trial published in the Journal of Cataract & Refractive Surgery.
Researchers from the University of Florida compared low-THC oral CBD with codeine-acetaminophen for controlling postoperative pain following photorefractive keratectomy (PRK), a laser procedure used to correct nearsightedness, farsightedness and astigmatism.
The prospective, randomized crossover trial included 35 adults who underwent PRK on each eye in separate procedures. Each participant received CBD after one procedure and codeine-acetaminophen after the other, with the order randomly assigned.
For the CBD portion of the trial, participants received 50 milligrams twice daily. For the comparison portion, they received tablets containing 30 milligrams of codeine and 300 milligrams of acetaminophen as often as every four hours.
Because each participant received both treatments, researchers were able to compare the medications within the same individuals rather than between two separate groups.
Pain peaked on the second day following surgery under both treatments. Researchers found no statistically significant difference between CBD and codeine-acetaminophen in either average or maximum pain ratings.
Visual acuity improved significantly by the third postoperative month, with no differences associated with which pain treatment participants received. Other symptoms and patient-reported outcomes were also similar between the two treatments.
Researchers did identify a possible first-exposure effect. Sensorium scores, measuring subjective changes in awareness or mental state, were significantly higher when participants received CBD following their first eye procedure. The difference was not observed when CBD was used following the second procedure.
The researchers described the changes as mild and said the treatment otherwise produced minimal side effects.
“Low-THC oral CBD provides non-inferior pain control to codeine-acetaminophen following PRK with similar recovery outcomes and minimal side effects,” the researchers concluded.
They said CBD may offer a viable opioid-sparing option for refractive surgery and potentially other forms of acute pain management.
The findings are limited by the trial’s small size and its focus on a single surgical procedure. Larger studies would be needed to determine whether CBD can consistently replace opioid medications following other operations or injuries.
The study was sponsored by Florida’s Consortium for Medical Marijuana Clinical Outcomes Research.