Topical NSAIDs effect on corneal sensitivity

Topical nonsteroidal antiinflammatory drugs (NSAIDs) are administered topically for a variety of ophthalmologic conditions. Brand diclofenac and brand ketorolac were previously shown to have topical anesthetic effects in addition to analgesic effects. Using the same method, we measured similar anesthetic effects of the 4 currently available topical NSAIDs--generic diclofenac, generic ketorolac, brand bromfenac, and brand nepafenac.

Baseline corneal sensitivity was measured on 10 healthy adult volunteers with a Cochet-Bonnet esthesiometer. One drop of the agent being studied was applied to the right eye every 5 minutes for a total of 4 drops. Corneal sensitivity was measured immediately after the last topical application and every 15 minutes for 60 minutes. After a 1-week washout period, a different agent was studied until all 4 NSAIDs were evaluated.

Corneal sensitivity profiles over time were similar for all NSAIDs. Corneal sensitivity decreased significantly from baseline immediately after topical application remaining flat from 0 to 30 minutes and then rising from 45 to 60 minutes back toward baseline in all treatment groups (P < 0.001). The maximal absolute drop in corneal sensitivity as measured by pressure thresholds was greatest for diclofenac [28.6 mm (95% confidence intervals {CI}, 19.8-37.4)], followed by ketorolac [21.1 mm (95% CI, 15.1-27.1)], bromfenac [16.9 mm (10.7-23.1)], and nepafenac [16.4 mm (95% CI, 12.7-20.1)]. Only diclofenac and nepafenac were statistically different in maximal decrease in sensitivity.

All 4 currently available NSAIDs demonstrated anesthetic effects similar to brand diclofenac and brand ketorolac.