Intraocular penetration of topical lidocaine 4%

J Cataract Refract Surg. 1999 May;25(5):642-7.


Purpose: To evaluate the intraocular penetration of lidocaine 4% topically applied before phacoemulsification.

Settings: Institute of Ophthalmology, University of Verona, and Department of Medical Pharmacology, University of Padua, Italy.

Methods: Thirty eyes having phacoemulsification for senile cataract were anesthetized by topical application of lidocaine 4%. The drug was applied 3 times in 30 minutes in 15 eyes and 6 times in 60 minutes in 15 eyes. At the beginning of surgery, aqueous humor samples were obtained to measure the lidocaine levels. Blood samples were obtained in 6 patients 30 and 60 minutes after aqueous humor collection. The aqueous humor levels were compared with the amount of pain perceived by patients during surgery.

Results: Mean aqueous humor lidocaine concentration was 8.68 micrograms/mL +/- 2.43 (SD) after 3 instillations and 23.21 +/- 8.87 micrograms/mL after 6 instillations. Blood levels of lidocaine were negligible. Patients whose intraocular level was below 12 micrograms/mL perceived more pain during surgery. Only 2 eyes had these low levels after 6 instillations.

Conclusions: Topically applied lidocaine 4% effectively penetrates the eye, providing analgesia for phacoemulsification. We suggest at least 6 instillations in the hour preceding surgery. In this study, pain during surgery was primarily related to poor intraocular levels of the anesthetic agent.

Publication types

  • Comparative Study

MeSH terms

  • Absorption
  • Aged
  • Aged, 80 and over
  • Anesthesia, Local / methods*
  • Anesthetics, Local / administration & dosage
  • Anesthetics, Local / pharmacokinetics*
  • Aqueous Humor / metabolism*
  • Blood-Aqueous Barrier
  • Chromatography, High Pressure Liquid
  • Female
  • Humans
  • Lidocaine / administration & dosage
  • Lidocaine / pharmacokinetics*
  • Male
  • Middle Aged
  • Ophthalmic Solutions
  • Pain Measurement
  • Phacoemulsification


  • Anesthetics, Local
  • Ophthalmic Solutions
  • Lidocaine