ATLA::Alternatives to Laboratory Animals

Volume 23, Number 4

The effects of carbocaine hydrochloride on isolated porcine corneas in vitro: a comparison of opacity, hydration and thickness.

ATLA 23, 539-545, July/August 1995

Haruyoshi Igarashi, Chiharu Sato, Katsuhiro Ogawa, Michio Kojima and Yuu Chiba

Department of Dental Pharmacology, Ohu University School of Dentistry, 31-1 Misumido, Tomita-machi, Koriyama-shi, Fukushima, 963-Japan

SUMMARY

Several concentrations of carbocaine hydrochloride, a local anaesthetic, were applied to isolated porcine corneas and stromas for periods of 1, 2, 3 and 4 hours. Increases in opacity (manifested as decreases in the intensity of a beam of light passed through the cornea from the epithebum to the endothelium), hydration (determined by the loss of water on drying to constant weight), and thickness (measured with a micrometer screw gauge) were determined. Small, time-related increases in opacity, associated with increases in hydration and thickness, were observed in control preparahons and in preparations treated with 0.5-2% carbocaine hydrochloride over a 4-hour incubation period. However, only those increases resulting from incubation for 4 hours with 2% carbocaine hydrochloride differed significantly from control values. Higher concentrations (8% and 16%) also caused opacity, but decreased hydration and thickness, probably because of the hypertonicity of these solutions.

Keywords: carbocaine hydrochloride, porcine cornea, corneal opacity, corneal hydration, corneal thickness