Viscoanesthesia. Part II: toxicity to intraocular structures after phacoemulsification in a rabbit model.
OBJECTIVE
To investigate the toxicity of a solution that combines sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to intraocular structures.


METHODS
Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.


METHODS
Phacoemulsification was performed in both eyes of 29 rabbits. They were divided into 3 groups; in each group (n = 7), 1 viscoanesthetic solution was used before capsulorhexis. After irrigation/aspiration, 0.2 mL of the solution was purposely left in the capsular bag. In 1 rabbit in each group, the solution was injected into the vitreous cavity through a posterior capsulorhexis. In 8 rabbits used as controls, balanced salt solution (BSS(R)) (n = 4) or sodium hyaluronate 1.5% (n = 4) was injected into the vitreous cavity. Enucleations were performed 15, 30, and 60 days postoperatively. Histological sections were cut and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson trichrome stains.


RESULTS
Light microscopic evaluation of the eyes enucleated after 15, 30, and 60 days in the study and control groups showed similar findings in intraocular structures such as the ciliary body and retina. No evidence of an inflammatory reaction, cell necrosis, or cell degeneration was observed in the histological sections.


CONCLUSIONS
The use of viscoanesthesia during phacoemulsification appeared to be safe, with no histologic abnormalities observed with the 3 lidocaine concentrations. The efficacy of the anesthetic effects of these solutions will be addressed in clinical trials.
Macky
Tamer A
TA
Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.
Werner
Liliana
L
Apple
David J
DJ
Izak
Andrea M
AM
Pandey
Suresh K
SK
Trivedi
Rupal H
RH
D000779:Anesthetics, Local / Q000633:toxicity*; D000818:Animals; D019923:Capsulorhexis; D002924:Ciliary Body / Q000187:drug effects / Q000473:pathology; D004338:Drug Combinations; D005123:Eye / Q000187:drug effects* / Q000473:pathology; D006820:Hyaluronic Acid / Q000633:toxicity*; D007903:Lens Capsule, Crystalline / Q000187:drug effects; D008012:Lidocaine / Q000633:toxicity*; D023421:Models, Animal; D018918:Phacoemulsification; D011817:Rabbits; D012160:Retina / Q000187:drug effects / Q000473:pathology
D000779:Anesthetics, Local; D004338:Drug Combinations; D006820:Hyaluronic Acid; D008012:Lidocaine