Gabapentin for Postoperative Pain After Photorefractive Keratectomy: A Prospective, Randomized, Double-blind, Placebo-controlled Trial

PURPOSE: To determine whether treatment with oral gabapentin reduces postoperative pain after photorefractive keratectomy (PRK). METHODS: This prospective, randomized, double-blind, placebo-controlled study comprised 40 patients scheduled for bilateral PRK. Exclusion criteria were previous refractive surgery; diseases that could affect epithelial healing; use of antihistamines, nonsteroidal anti-inflammatory drugs, or steroids; and use of mitomycin C during PRK. Patients were divided into two groups: 20 patients received gabapentin capsules (300 mg) and 20 patients received identical placebo capsules. Visual acuity, slit-lamp examination, and a 12-question, 10-point visual numerical scale questionnaire were evaluated at each postoperative follow-up. Main outcome measures were the severity of pain at each follow-up and during the previous 24 hours. Secondary outcome measures were maximum and minimum severity of pain, healing time, uncorrected distance visual acuity, and the rating of other symptoms and potential side effects. RESULTS: The gabapentin group had less pain during the first 72 hours (P=. 024 to .001). A significant difference in favor of gabapentin was found for the first 48 hours regarding minimum pain severity (P=. 005 and .01 for 24 and 48 hours, respectively) and for the first 72 hours for maximum pain severity (P=. 014, .007, and .001 for 24, 48, and 72 hours, respectively). No significant differences were observed for side effects, symptoms, or healing time except discomfort in favor of gabapentin during the first 24 hours (P=. 043). CONCLUSIONS: Gabapentin significantly reduced postoperative pain after PRK compared to placebo, with no increase in reported side effects. [J Refract Surg. 2011; 27(8): 613-617.] doi:10.3928/1081597X-20110210-01