MAR 11, 2011
The authors of this study hypothesize that there is no clinical difference in analgesic effectiveness between some of the most common topical anesthetics used for intravitreal injection.
To test this hypothesis, they conducted a double-blind study that randomized 93 patients scheduled to receive an intravitreal injection for wet AMD to 0.5% tetracaine hydrochloride drops and a 4% lidocaine pledget, 0.5% tetracaine hydrochloride drops alone, or 4% cocaine drops alone. Patients scored their pain experience using a visual analogue scale immediately following and 15 minutes after their injection. The primary outcome wasthe average of these scores. The physician performing the procedure separately scored his perception of the patients' pain using the Wong-Baker FACES scale.
Patient reported pain was similar among the groups, as was the physician's perception of patients' pain. The authors conclude that this study validates their hypothesis and lends support to the use of topical anesthetic agents for intravitreal injections.