Oral Gabapentin for the Treatment of Postoperative Pain after Photorefractive Keratectomy

Purpose

To evaluate oral gabapentin for postoperative pain after photorefractive keratectomy (PRK).

Design

Prospective, nonrandomized clinical trial.

Methods

In additional to a standard regimen of topical antibiotics, topical steroids, and topical tetracaine as required, all PRK patients at our laser vision center were treated after surgery for pain for a two-month period with Percocet (oxycodone/acetaminophen) [Endo Pharmaceuticals; Chadds Ford, Pennsylvania, USA] 5 mg/325 mg as required for three days (control group). Patients completed a pain assessment survey using a faces pain scale (from zero through 6) on the evening of surgery and each subsequent morning and evening until postoperative day 3. A successive cohort of patients received Neurontin (gabapentin) [Pfizer, New York, New York, USA] 300 mg thrice daily (first dose administered two hours or more before the procedure) as an oral pain medication for three days, and the same survey data were collected.

Results

Data were collected on 141 patients in each cohort. Successful pain management score (defined as faces zero through 2 on the scale) differences did not reach statistical significance between the two cohorts except on the morning of the second postoperative day, when gabapentin was superior. On all postoperative days, patients in the oxycodone/acetaminophen cohort used significantly less tetracaine eye drops as required. The percent of patients rating overall pain experience as better than expected was 35% and 36%, those rating pain experience as about what was expected was 50% and 49%, and those rating pain experience as worse than expected was 15% and 15% in the oxycodone/acetaminophen and gabapentin cohorts, respectively.

Conclusions

We found no difference in overall subjective pain management ratings between gabapentin and oxycodone/acetaminophen for postoperative PRK pain, although gabapentin was associated with significantly more frequent use of anesthetic eye drops as required.