A Comparison of Pregabalin (Lyrica®) to Placebo in Pain Relief After Photorefractive Keratectomy (PRK) Surgery

A Comparison of Pregabalin (Lyrica®) to Placebo in Pain Relief After Photorefractive Keratectomy (PRK) Surgery

A Comparison of Pregabalin (Lyrica®) to Placebo in Postoperative Pain Relief of Patients Status-post Photorefractive Keratectomy: A Double-masked Randomized Prospective Study

The purpose of this study is to compare the efficacy of pregabalin to placebo for postoperative pain control after photorefractive keratectomy.

Study subjects will be taken from a standard group of typical candidates for PRK surgery including active duty and DoD (Department of Defense) beneficiaries. Prior to being approached for the study, all patients will have had a previous desire for surgery and had a pre-operative evaluation indicating healthy ocular status. Patients scheduled for PRK surgery will be briefed on the purpose of the study and invited to participate at the preoperative appointment. After the consent process, patients will be randomized in a 1:1 fashion to receive either oral pregabalin 75mg twice daily or placebo for pain control, in addition to the standard care treatment of as needed Percocet and tetracaine ophthalmic drops. Subjects will be evaluated daily for 4 days post-operatively for subjective pain assessment, adverse drug events and compliance, use of concomitant medications as well as monitoring of healing time. Quality of life will be measured at baseline and post-op day 2 when the peak of pain is anticipated. Analysis will be performed to detect an approximate 10% improvement in pain scores. Secondary outcomes will include measuring healing time, quality of life and use of rescue medications.

1 capsule (75 mg) by mouth twice daily starting two hours prior to surgery and continuing 4 days postoperatively.

1 capsule by mouth twice daily starting two hours prior to surgery and continuing 4 days postoperatively.

Determine if clinical efficacy is achieved with pregabalin administered prior to PRK and continued for 5 days. This will be evaluated using the short-form McGill pain questionnaire (SF-MPQ). Primary efficacy is assessed on 100mm Visual Analog Scale (VAS); total range is 0 to 100. A score closer to zero indicates a better outcome of less pain.

Determine if clinical efficacy is achieved with pregabalin administered prior to PRK and continued for 5 days. This will be evaluated using the short-form McGill pain questionnaire (SF-MPQ). Secondary efficacy is assessed with present pain intensity (PPI) score. Scale is 0 (no pain) to 5 (excruciating pain)

Determine if clinical efficacy is achieved with pregabalin administered prior to PRK and continued for 5 days. This will be evaluated using the short-form McGill pain questionnaire (SF-MPQ). Secondary efficacy is assessed using the Total MPQ Score. Scale minimum is 0 (no pain) to maximum of 45 (severe pain). A higher score indicates a worse outcome.

Determine if there was an improvement in the patient's functional health and well-being associated with pregabalin compared to standard of care as assessed by Brief Pain Inventory-short form (BPI-SF). Data was assessed on the day of surgery (Day 0) and at the expected peak of pain, postop Day 2 in the morning. Scale is minimum 0 (no pain) to maximum of 10 (pain as bad as you can imagine). A higher score indicates a worse outcome.

Determine if there was a reduction in the need for use of rescue pain medications, Percocet and tetracaine, in those subjects who received pregabalin. Total number of doses was collected. A higher number of doses required indicates a worse outcome.

Determine if there was a reduction in healing time associated with pregabalin as seen with daily slit-lamp observation. Epithelial defect was measured at post-operative day 3, 5, 7, and 9 in each eye. A higher number of days required for healing indicates a worse outcome.

Inclusion Criteria: Healthy ocular status Stable preoperative refractive anisometropia Consented to the PRK surgical procedure Exclusion Criteria: Pregnant or breastfeeding Diagnosed with autoimmune disease or diabetes Patients with a known adverse reaction or hypersensitivity to gabapentin or pregabalin Patients only desiring PRK on one eye Patients with history of drug use/abuse/addiction Patients who are on chronic pain medications Patients currently taking anti-epileptic, antidepressant and/or anti-psychotic medications Patients with a history of suicidality Patients with chronic renal insufficiency (defined as estimated creatinine clearance less than 30ml/min or Scr ≥ 2.0) 10) Patients who have experienced angioedema, or have heart failure

Meek JM, Rosbolt MB, Taylor KR, Fusco EA, Panday VA, Reilly CD. Pregabalin versus placebo in postoperative pain relief of patients' status post photorefractive keratectomy: a double-masked, randomized, prospective study. J Ocul Pharmacol Ther. 2014 Sep;30(7):527-32. doi: 10.1089/jop.2013.0208. Epub 2014 Jun 10.