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

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 www.randomizer.org 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:

• "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.
• "How many tablets of study-related pain medication did you take today in the AM/PM?"
• "How many times did you use topical tetracaine today in the AM/PM?"
• "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.

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