Efficacy and safety of three ophthalmic inserts for topical anaesthesia of the cornea. An exploratory comparative dose‐ranging, double‐blind, randomized trial in healthy volunteers

Background Cataract surgery requires prolonged anaesthesia, concomitant with permanent hydration and lubrication of the cornea, in order to provide a clear view of the operation area. Aims The primary objective of the study was to assess several formulae of a soluble ophthalmic insert: TOPICSERT [bupivacaine (Bupi) + hyaluronic acid (HA) or sodium hyaluronate] in terms of complete and long‐lasting anaesthesia of the cornea. The hydration properties of HA were not assessed in this study. Methods In a prospective double‐blind, cross‐over, randomized study, with latin‐square allocation of treatments, 16 healthy volunteers received a single dose of each formula (A, 1 mg Bupi and 0.1 mg HA; B, 0.5 mg Bupi and 0.1 mg HA; C, 1 mg Bupi and 0 mg HA, and D acting as a placebo) via the ocular route with 1 week of wash‐out between each period. Corneal anaesthesia was measured using a Cochet‐Bonnet esthesiometer. Results There was a statistically significant difference between treatments with regard to the main criterion (complete anaesthesia lasting at least 20 min) when general association statistics were used (Mantel–Haenzel test, P