Abstract
Purpose: :
Patients are distressed by the pain and subconjunctival hemorrhage (SCH) associated with intraocular medicine injections. Many practitioners anesthetize the injection site with subconjunctival lidocaine (SCL) and try to minimize the time before injection for clinical efficiency. The optimal wait time is uncertain. Studies comparing topical and subconjunctival anesthesia have used varying wait times. In these studies, the mean 10-point pain score after waiting 30 seconds was 3.3 and after 1-2 minutes was 1.83. No previous report has specifically investigated the wait time that will maximize both patient comfort and appearance as well as clinical efficiency for the practitioner. The purpose of this study is to determine that optimal time.
Methods: :
Prospective randomized study. Twenty-six consecutive eligible patients who had not received an intraocular injection for at least one year were randomly assigned to one of three groups: wait time of 2 minutes (n=9), 3 minutes (n=9) or 4 minutes (n=8). All patients received 0.2 ml of 2% SCL with a 30-gauge needle. Pain after SCL anesthesia was graded on a 10-point scale, and any SCH was measured in clock-hours. After bevacizumab injection with a 30-gauge needle, pain and SCH were again recorded. Data was analyzed by ANOVA.
Results: :
SCL anesthesia mean pain scores [0.4 ± 0.6 (2 minutes), 0.2 ± 0.4 (3 minutes), 0.4 ± 0.7 (4 minutes)] were not significantly different (p=0.7). Only one patient in the 2 minute group had SCH. The mean pain scores after bevacizumab injection showed a decreasing trend with longer wait time [0.9 ± 1.3 (2 minutes), 0.6 ± 0.7 (3 minutes), 0.4 ± 0.6 (4 minutes)], but this was not statistically significant (p=0.5). Post-injection SCH was greater in the 4 minute group (1.4 ± 0.9 clock-hours) versus 2 or 3 minutes (0.8 ± 0.9 clock-hours for both) but not significantly (p=0.3).
Conclusions: :
SCL anesthesia resulted in minimal discomfort and rare SCH and is a valid anesthetic technique for intraocular bevacizumab injection. Waiting minutes longer between lidocaine and intraocular injection may decrease patient discomfort but may result in greater SCH at 4 minutes.