Abstract
Purpose:
To investigate the safety to the cornea; and efficacy of five concentrations (2%, 3.5%, 5%, 8% and 12%) of anesthetic gel for intravitreal administration of pharmacologic agents.
Methods:
After approval of the Ethics Committee, a prospective, randomized and double-blinded clinical trial using lidocaine gel in five preparations, 2%, 3.5%, 5%, 8% and 12%, was conducted. Patients scheduled for intravireal treatment received topical anaesthesia with lidocaine gel five and ten minutes before the procedure. After intravitreal injection, patients answered the Visual Analogue Pain scale (VAS) about pain during the procedure. Corneal and conjunctival staining with lissamine green and fluorescein was measured in the first post-operative day using Oxford Scale. Statistics analysis were performed with SPSS for Windows (SPSS for Windows Version 17, Chicago, IL) and the level for significance was p<0.05.
Results:
Two hundred sixty patients were allocated into five groups with a mean age of 70.07(±13.3). The groups were similar in gender, drug administrated, pathology and eye treated (p >0.05). We treated patients with AMD, diabetic macular edema, central or branch vein occlusion and edema secondary to other diseases. There was an inverse correlation between age and pain (ρ=0.239, p<0.001). The mean pain score in 2% lidocaine was highest 2.63 (±1.68), comparing with other groups, in 3.5% was 2.08 (±1.35), in 5% was 2.00 (±1.65), in 8% was 1.93 (±1.40) and in 12% was 1.83 (±1.35). Confronting each group, there was a significant difference between mean pain score in 2% lidocaine group compared to all other groups, 5% (p=0.041), with 8% (p=0.02) and with 12% (p=0.012). There was no significant difference between groups in regard to keratitis mean score (p=0.897) and for the lissamine green (p= 0.397).
Conclusions:
Lidocaine gel 3.5%, 5%, 8% and 12% induced less pain than 2 % topical ocular anestesia for intravitreal injection. In this study, we didin’t observe relationship between concentration of lidocaine and corneal toxicity . No systemic effects were observed.
Keywords: 412 age-related macular degeneration •
561 injection •
762 vitreoretinal surgery