Viscoanesthesia. Part I: toxicity to corneal endothelial cells in a rabbit model.
OBJECTIVE
To evaluate the toxicity of a solution combining sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to the rabbit corneal endothelium.


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


METHODS
Each rabbit cornea was excised, and the endothelium was exposed to 1 of the following solutions for 20 minutes: viscoanesthetic solution (0.5%, 1.0%, or 1.65% lidocaine in sodium hyaluronate 1.5%; 5 corneas each), sodium hyaluronate 1.5% (n = 5), balanced salt solution (BSS(R)) (n = 5), mitomycin-C 0.02% (n = 2), dextran 15% (n = 2), or distilled water (n = 2). The endothelium was then stained with trypan blue and alizarin red. Two corneas were stained immediately after excision. Cell morphology and damage to the corneal endothelium were analyzed by microscopic examination.


RESULTS
The endothelium in the corneas of the viscoanesthetic groups was comparable to that in the sodium hyaluronate 1.5% and the BSS groups and to the corneas not exposed to any solution. In some areas of the 1.0% and the 1.65% viscoanesthesia groups, the corneal endothelial cells presented irregular intercellular borders. Staining with trypan blue, which indicates cellular damage, was observed in some linear areas corresponding to corneal folds in all groups. The folds were probably caused during manipulation for corneal excision and staining. The corneal endothelium was destroyed in the mitomycin group. In the dextran and distilled-water groups, morphological alterations probably resulting from osmotic changes were observed.


CONCLUSIONS
The 3 concentrations of viscoanesthetic solutions appeared to be safe to rabbit corneal endothelium.
Trivedi
Rupal H
RH
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
Macky
Tamer A
TA
D000085:Acetates / Q000633:toxicity; D000779:Anesthetics, Local / Q000633:toxicity*; D000818:Animals; D000880:Anthraquinones; D004396:Coloring Agents; D004338:Drug Combinations; D004728:Endothelium, Corneal / Q000187:drug effects* / Q000473:pathology; D006820:Hyaluronic Acid / Q000633:toxicity*; D008012:Lidocaine / Q000633:toxicity*; D008903:Minerals / Q000633:toxicity; D016685:Mitomycin / Q000633:toxicity; D023421:Models, Animal; D011817:Rabbits; D012965:Sodium Chloride / Q000633:toxicity; D013194:Staining and Labeling / Q000379:methods; D014343:Trypan Blue
D000085:Acetates; D000779:Anesthetics, Local; D000880:Anthraquinones; C030660:BSS solution; D004396:Coloring Agents; D004338:Drug Combinations; D008903:Minerals; D012965:Sodium Chloride; D016685:Mitomycin; C010078:alizarin; D006820:Hyaluronic Acid; D008012:Lidocaine; D014343:Trypan Blue