Randomized trial of anesthetic methods for intravitreal injections

Abstract

Purpose: To compare the effectiveness of four different anesthetic methods for intravitreal injection.

Methods: Twenty-four patients each received four intravitreal injections using each of four types of anesthesia (proparacaine, tetracaine, lidocaine pledget, and subconjunctival injection of lidocaine) in a prospective, masked, randomized block design. Pain was graded by the patient on a 0 to 10 scale for both the anesthesia and the injection.

Results: The average combined pain scores for both the anesthesia and the intravitreal injection were 4.4 for the lidocaine pledget, 3.5 for topical proparacaine, 3.8 for the subconjunctival lidocaine injection, and 4.1 for topical tetracaine. The differences were not significant (P = 0.65). There were also no statistical differences in the individual anesthesia or injection pain scores. Subconjunctival lidocaine injection had the most side effects.

Conclusion: Topical anesthesia is an effective method for limiting pain associated with intravitreal injections.