LAUSR

PURPOSE To determine the effect of different durations of topical anesthesia on intravitreal injection (IVI) pain. METHODS This was a double-blinded randomized comparative study. Three hundred and twelve sequential eyes undergoing IVI were randomized to one of six groups according to the duration of topical anesthesia (from 1 to 30 minutes, one group for every 5-minute range, Group 1-6). Topical anesthesia before IVI was standardized. Patients graded their pain using the visual analogue scale (VAS) and the Wong-Baker FACES Scale (WBF) at 15 minutes after the procedure. RESULTS The pain scores among the six groups were significantly different for the VAS (P = 0.013) and WBF (P = 0.024). The mean pain scores for Group 4 were 1.97 ± 1.04 (VAS) and 2.02 ± 1.08 (WBF) and were significantly lower than those of Group 1, 2, 5, or 6. CONCLUSION The duration of topical anesthesia was significantly correlated with IVI pain. Preoperative 0.5% proparacaine hydrochloride drops were most effective in relieving IVI pain 11-20 minutes after topical administration.