Safety and efficacy of various concentrations of topical lidocaine gel for intravitreal injection

Intravitreal injection (IVT) is one of the most common vitreoretinal procedures, a large majority are performed with local anesthesia. The purpose of this study was to investigate the safety to the cornea and anesthetic efficacy of five concentrations of lidocaine gel.A prospective clinical trial was conducted testing lidocaine gel in five preparations: 2, 3.5, 5, 8 and 12%. Patients with macular degeneration, diabetic edema or retina vein occlusion were scheduled for intravitreal treatment received topical anesthesia with lidocaine gel 5 and 10 min before the procedure. Patients answered the visual analog scale for pain during the procedure. Corneal and conjunctival was evaluated using the Oxford scale.In total, 260 patients were randomized into five groups. The mean pain scores (± standard deviation) were 2.63 (± 1.68) in the 2% group, 2.08 (± 1.35) in the 3.5%; 2.00 (± 1.65) in the 5%, 1.93 (± 1.40) in the 8% and 1.83 (± 1.35) in the 12% group. Mean pain score among all groups was similar (p = 0.077). There was no significant difference between groups in regard to keratitis mean score (p = 0.897).Lidocaine gel at concentrations from 2 to 12% induced similar anesthetic effect for IVTs, without adverse effects on cornea and conjunctiva.