Comparison of the analgesic efficacy and safety of nepafenac ophthalmic suspension compared with diclofenac ophthalmic solution for ocular pain and photophobia after excimer laser surgery: a phase II, randomized, double-masked trial.

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of nepafenac ophthalmic suspension 0.03% and 0.1% for the treatment of postoperative pain and photophobia in patients undergoing excimer photoreactive keratectomy (PRK).

METHODS

In this 7-day, randomized, double-masked, parallel-group trial at 2 sites, patients undergoing PRK surgery were randomly assigned to receive nepafenac ophthalmic suspension 0.03% or 0.1%, or diclofenac sodium ophthalmic solution 0.1%. Patients were treated on day 0 (surgery) and day 1 (the day after surgery). The dose regimen for all 3 treatments was the same. On day 0, patients received 2 drops in the operative eye -1 hour before surgery; 2 drops within 1 hour after surgery; 1 drop -4 hours after the first postoperative dose; and 1 drop -8 hours after the first postoperative dose. On day 1, patients instilled 1 drop of study drug QID. Thereafter, the study medication was discontinued. In the perioperative period, study personnel instilled the drops. The patients instilled the drops when they went home. Patients recorded pain and photophobia from day 0 through day 2, rating pain from 0 to 9 on a visual analog scale (0=none, 9=extreme) and photophobia from 0 to 3 on an ordinal, categoric scale (0=none, 3=severe). Patients were permitted to take acetaminophen 500 mg as needed for pain. They returned for postoperative follow-up visits on days 1, 3, and 7. Adverse events were documented when reported by the patients themselves, and when study personnel asked about specific events.

RESULTS

Sixty patients (20 per group) were enrolled. On the day of surgery, there were no significant differences between groups, except at 3 hours after surgery, when the nepafenac 0.03% group had a significantly higher mean pain score than the nepafenac 0.1% group (4.0 vs 3.0; P<0.038). On day 2, the nepafenac 0.1% group had less pain at bedtime than the diclofenac group (mean score, 1.9 vs 3.1; P<0.024) and less photophobia in the morning (mean score, 1.2 vs 1.8; P<0.023). For the nepafenac 0.03% group, the mean pain and mean photophobia scores were 2.5 and 1.6, respectively. There were no significant differences between the 3 treatment groups in the proportion of patients who took acetaminophen for pain at any time point (P=NS). There was no statistically significant difference in corneal re-epithelialization rates among the 3 groups. Adverse events were infrequent, and no serious adverse events occurred. Two ocular adverse events related to therapy occurred: a corneal infiltrate in 1 patient in the nepafenac 0.03% group; and ocular discomfort in 1 patient in the nepafenac 0.1% group. Both patients continued the study.

CONCLUSIONS

Both nepafenac 0.03% and 0.1% were effective for treatment of pain and photophobia in these patients undergoing PRK surgery. There was no difference in the proportion of patients who took rescue acetaminophen for pain. All treatments were well tolerated in these patients.