title: Comparative Study Between Lidocaine Gel 2% and 5% for Ophthalmic Procedures.
abstract: To compare same-day pain control and safety of 2 different anesthetic gels utilizing 5% and 2% lidocaine gel. Main outcome is to determine whether 5% lidocaine gel is more effective in decreasing pain during conjunctival clamping compared to 2% lidocaine gel 5 and 10 min after gel application.
  
  
  
  This is a prospective, randomized double-blind clinical trial. Patients were randomized to receive 2% or 5% lidocaine gel in each eye. Discomfort during the gel instillation and pain during conjunctival clamping 5 and 10 min after gel application were compared. Extent of corneal conjunctival staining was graded according to the Oxford scale.
  
  
  
  Eighty eyes of 40 patients were enrolled. The groups were similar in gender, with a mean age of 48 ± 16.26 years. The 5% lidocaine gel resulted in higher discomfort during initial instillation (P = 0.092), however, the pain during conjunctival clamping was lower in the 5% lidocaine gel eyes (P = 0.564) in both 5 and 10 min later (P < 0.001). The majority of patients (80%) had no corneal conjunctival dye staining. The tear break-up time was not statistically different after lidocaine gel 2% (20.35 ± 7.37 s) and lidocaine 5% (19.75 ± 7.00 s).
  
  
  
  Five percent and 2% lidocaine gel have similar efficacy controlling pain 5 min after instillation, however, 5% lidocaine gel appears to be more effective with a longer duration of action, without corneal toxicity. There was no corneal toxicity noted with either concentration.
authors.affiliation: 1 Department of Ophthalmology and Visual Sciences, Paulista School of Medicina, Federal University of São Paulo , São Paulo, Brazil .
authors.forename: Hélio Francisco
authors.initials: HF
authors.lastname: Shiroma
authors.affiliation: 1 Department of Ophthalmology and Visual Sciences, Paulista School of Medicina, Federal University of São Paulo , São Paulo, Brazil .
authors.forename: Kleber Eidi
authors.initials: KE
authors.lastname: Shimono
authors.affiliation: 1 Department of Ophthalmology and Visual Sciences, Paulista School of Medicina, Federal University of São Paulo , São Paulo, Brazil .
authors.forename: Michel Eid
authors.initials: ME
authors.lastname: Farah
authors.affiliation: 2 Department of Ophthalmology, Bascom Palmer Eye Institute , Miami, Florida.
authors.forename: Raquel
authors.initials: R
authors.lastname: Goldhardt
authors.affiliation: 1 Department of Ophthalmology and Visual Sciences, Paulista School of Medicina, Federal University of São Paulo , São Paulo, Brazil .
authors.forename: Astor
authors.initials: A
authors.lastname: Grumann
authors.affiliation: 1 Department of Ophthalmology and Visual Sciences, Paulista School of Medicina, Federal University of São Paulo , São Paulo, Brazil .
authors.forename: Eduardo Buchele
authors.initials: EB
authors.lastname: Rodrigues
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D005260:Female; D005782:Gels / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D005782:Gels; D008012:Lidocaine