Comparison of 3 different anesthetic approaches for intravitreal injections: a prospective randomized trial

To compare the anesthetic effectiveness of topical proparacaine drops, subconjunctival lidocaine, and 2% lidocaine gel.

Ninety-two patients undergoing intravitreal injections were randomized to 1 of 3 groups: proparacaine 0.5% drops (Group Drops), proparacaine 0.5% drops plus subconjunctival lidocaine (Group SC), or 2% lidocaine gel (Group Gel). Patients were asked to score their pain experience using a visual analog scale of 0 to 10 immediately following the injections and 10 min, 1 h, 6 h, and 24 h after the injections. Patients also graded the overall injection experience as Excellent, Very Good, Fair, Poor, or Awful. The physician evaluated the patients' eye movement during intravitreal injection on 3 levels: (0) none or minimal, (1) not compromising the injection, and (2) compromising the injection.

The patients in Group Drops had the worst mean pain scores during the injection and 10 min after, with the highest occurrence of movements compromising the procedure (Grade 2; 38.7%). The patients in Group SC had a higher percentage of good experiences (37.9%) but a higher incidence of chemosis (16.7%). The patients in Group Gel had similar overall pain scores to Group Drops patients but a higher incidence of keratitis (19.4%). There was no statistically significant correlation between the use of aspirin or anticoagulants and the occurrence of hyperemia or hyposphagma.

Subconjunctival lidocaine was most effective in preventing pain and eye movements during intravitreal injections. Although 2% lidocaine gel produced a good overall experience for the patients, the incidence of keratitis was very high (19.4%). Therefore, we do not recommend 2% lidocaine gel as the first anesthetic choice for intravitreal injections. There is no evidence to suspend the use of aspirin or other anticoagulants drugs prior to intravitreal injections.