Randomized clinical trial of two anesthetic techniques for intravitreal injections: 4% liquid lidocaine on cotton swabs versus 3.5% lidocaine gel

Abstract

Objective: To compare same-day and next-day pain control and safety of two anesthetic techniques utilizing 4% liquid lidocaine applied with sterile cotton swabs versus 3.5% lidocaine gel for intravitreal injections. Main outcome measures were: discomfort during anesthetic preparation and needle penetration, 1 and 24 h after injection.

Methods: Patients were randomized to alternate anesthetic method at two consecutive injections in one eye or in different eyes on the same day if requiring bilateral injections. Overall satisfaction, corneal staining, and subconjunctival hemorrhage (SCH) were compared.

Results: Fifty patients were enrolled. Both methods resulted in similar mild discomfort during anesthetic preparation, 1 and 24 h later. The gel resulted in slightly higher discomfort during needle penetration (p = 0.026). Patients were satisfied with both techniques (p = 0.91), however, 52% patients preferred gel, 33% were indifferent, and 15% preferred cotton swabs (p = 0.002). There were significantly less corneal staining (p = 0.001) and SCH (p = 0.004) after the gel.

Conclusion: Both techniques are equally effective and yield mild discomfort scores during the procedure and the next day. The gel method results in significantly less ocular surface irritation.

Keywords::

• anesthesia
• discomfort
• intravitreal injection
• lidocaine
• lidocaine gel
• pain

Acknowledgements

The study was registered on the ClinicaTrials.gov with the following Identifier NCT01087489. The data outlined in this manuscript were partially presented at the 2011 Angiogenesis meeting, Miami, February, 2011; the Association for Research in Vision and Ophthalmology, Fort Lauderdale, May, 2011; the American Society of Retina Specialists, Boston, August, 2011.