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Updated: Aug 6, 2026
Use of the Operant Orofacial Pain Assessment Device (OPAD) to Measure Changes in Nociceptive Behavior
Published on: June 10, 2013
Randomized, controlled crossover comparison of oral cannabidiol with oral opioid for postoperative PRK pain control
Yujia Zhou1, Kayla Swiatek, Andrew Nguyen
1From the Department of Ophthalmology, University of Florida, Gainesville, Florida (Zhou, Swiatek, Tuli, Steigleman); University of Florida College of Medicine, Gainesville, Florida (Nguyen).
Purpose:
To compare the safety and efficacy of low-tetrahydrocannabinol (THC) oral cannabidiol (CBD) with oral codeine-acetaminophen for postoperative pain control after photorefractive keratectomy.
Setting:
Academic outpatient clinical practice.
Design:
Prospective, randomized, crossover, self-controlled clinical trial.
Methods:
35 adults underwent bilateral sequential PRK, receiving oral CBD (50 mg twice daily) for one eye and oral T3 (codeine-acetaminophen 30 to 300 mg every 4 hours) for the contralateral eye in a randomized sequence. Primary outcomes included pain and uncorrected visual acuity at month 3. Secondary outcomes included diary-reported symptoms and patient-reported quality-of-life scores: Patient-Reported Outcomes With LASIK, Quality-of-Life Impact of Refractive Correction, and Ocular Surface Disease Index.
Results:
Pain scores peaked on postoperative day 2 across both interventions with no significant difference in mean or maximum pain ratings ( P = .538). Visual acuity improved significantly by postoperative month 3 ( P < .001), with no treatment-related differences ( P = .928). Sensorium was significantly higher when taking CBD for the first eye, and not the second eye, indicating first-exposure effect ( P = .035). Other symptoms and outcomes were equivalent between treatments.
Conclusions:
Low-THC oral CBD provides noninferior pain control to codeine-acetaminophen after PRK with similar recovery outcomes and minimal side effects. Mild sensorium changes may occur in surgically naïve patients taking CBD. CBD may represent a viable opioid-sparing alternative in refractive surgery or acute pain management.
