Post-operative Pain Control After Photorefractive Keratectomy Comparing Acetaminophen/Codeine vs Acetaminophen/Oxycodone


Photorefractive keratectomy (PRK) is a refractive error correction procedure that helps eliminate or reduce the dependence on corrective lenses. An important aspect of PRK is post-operative pain management. Post-operative pain can be significant in the first three to five days and is typically controlled utilizing various modalities including narcotic pain medication. Simple observation suggests a difference in the post-operative pain levels of patients utilizing the more potent oxycodone- versus the less potent codeine-containing acetaminophen preparations. There have been no studies performed to explore any differences in perceived pain comparing these two medications when used following PRK. This study is designed to answer this question by means of a pain survey conducted in the first five days post-op. This may help better manage similar patients in the future.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Supportive Care
    • Masking: Double (Participant, Investigator)
  • Study Primary Completion Date: October 28, 2019

Detailed Description

This will be a prospective pain assessment study utilizing a simple three question survey given to patients undergoing bilateral PRK. Following recruitment and enrollment (see section 4.1 and 4.2 for recruitment and consent process), patients will be randomized to be prescribed either 1) Group 1: codeine 30mg/acetaminophen 300mg (standard of care dosage) or 2) Group 2: oxycodone 5mg/acetaminophen 325mg (standard of care dosage) post-operatively. All post-operative patients will receive standard bandage contact lenses and as needed tetracaine as per standard of care. Patients will be removed from the study if they take other non-study pain medications. They will be asked to record their pain levels four times daily as well as the number of as needed narcotic pain medication taken and the number of tetracaine drops used (to isolate a potential confounding pain control modality). Randomization will be performed with the aid of which will generate a randomized assignment to either group 1 or group 2. All PRK procedures will be performed per standard of care. The procedure will be performed by one of the 4 approved surgeons. All surgeons will use the same technique using either the VISX or the Allegretto laser machines. This technique will include use of a brush for mechanical removal of corneal epithelial cells. The surgeons will take note at this time of the relative adherence of the epithelium to the underlying tissue and grade the adherence on a scale of 0-4 (0=least adherent and 4=most adherent). In the data analysis, differences between surgeons and between operating platform (VISX vs Allegretto) will be compared to account for any possible bias in operating parameters. The survey will be worded as follows: 1. "Rate your eye pain or level of discomfort at 0800, 1200, 1600 and 2000. Please write the number closest to your response in the table below under the appropriate day and time. 2. "How many tablets of study-related pain medication did you take today in the AM/PM?" 3. "How many times did you use topical tetracaine today in the AM/PM?" 4. "Did you take any other non-study related pain medications?" Patients will be followed-up post-operatively as per standard of care. This includes follow-up visits at 1 day, 1 week, 1 month, 3 months, 6 months and 12 months. Starting on post-operative day 1, the patients will be asked to record their pain levels using the pain survey at four hour intervals (0800, 1200, 1600, 2000). At the 1 week post-operative visit, the pain surveys will be collected from the patients. Visual acuity data will be extracted from all but the 12 month follow-up appointment and used as a secondary outcome to correlate any possible differences in pain scores to functional outcomes in terms of visual acuity.


  • Drug: acetaminophen/codeine vs acetaminophen/oxycodone
    • pain medications

Arms, Groups and Cohorts

  • Active Comparator: Acetaminophen with codeine
    • codeine 30mg/acetaminophen 300mg Take one to two tablets every 4 to 6 hours as needed for pain for up to 4 days following surgery.
  • Active Comparator: Acetaminophen with oxycodone
    • oxycodone 5mg/acetaminophen 325mg Take one tablet every 4 to 6 hours as needed for pain for up to 4 days following surgery.

Clinical Trial Outcome Measures

Primary Measures

  • Post-operative median daily pain scores
    • Time Frame: 1 week after surgery
    • The PRK Post-Operative Pain Survey consisted of a scale of 0 – 10 with a score of 0 equal to no pain, a score of 1 – 3 equal to mild pain, a score of 4 – 6 equal to moderate pain and a score of 7 – 10 equal to severe pain

Secondary Measures

  • Post-operative visual acuity
    • Time Frame: Post-operative day 1, week 1, and month 1,3 and 6.
    • Visual acuity will be tested at each post-operative visit.

Participating in This Clinical Trial

Inclusion Criteria

  • M/F >21 years of age (PRK is not done on anyone under the age of 21 at this surgery center) – Have met all criteria for bilateral PRK Exclusion Criteria – Patients who do not meet the criteria for refractive surgery – Patients receiving LASIK – Patients known to have an allergy to either of the study pain medications – Patients receiving refractive surgery on only one eye – Pregnant women, children, military basic trainees, prisoners and detainees – Subject has used narcotics in the last 6 months

Gender Eligibility: All

Minimum Age: 21 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • 59th Medical Wing
  • Provider of Information About this Clinical Study
    • Principal Investigator: Charisma Evangelista, Chief of Refractive Surgery – 59th Medical Wing
  • Overall Official(s)
    • Charisma B Evangelista, MD, Principal Investigator, 59th Medical Wing

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