A sub-Tenon's capsule injection of lidocaine induces extraocular muscle akinesia and mydriasis in dogs

作者：Ahn J S; Jeong M B; Park Y W; Lee Y S R; Lee E R; Kim S H; Lee I; Seo K^*

来源：Veterinary Journal, 2013, 196(1): 103-108.

DOI：10.1016/j.tvjl.2012.08.012

• Sub-Tenon's anaesthesia
• Akinesia
• Mydriasis
• Lidocaine
• Dog

The effect of local anaesthetic on the extraocular muscles was investigated in dogs by injecting lidocaine into the space between Tenon's capsule and the sclera. A cross-over design was used with both eyes from five Beagle dogs randomly injected, under general anaesthesia, with 1 mL of 2% lidocaine (1 mL-lidocaine group), 2 mL of 2% lidocaine (2 mL-lidocaine group) or 2 mL of normal saline (control group). Each eye was assigned to all treatments with a minimum 14 day interval between injections. Changes in eye position, pupil diameter, and intraocular pressure (IOP) were evaluated during the procedure.
All eyes in the 2 mL-lidocaine group exhibited akinesia and mydriasis (pupil diameter >10 mm) with an onset time of 6.5 +/- 4.9 and 4.2 +/- 4.3 min, respectively. In the 1 mL-lidocaine group, akinesia was induced in nine eyes and mydriasis occurred in seven eyes at 10.7 +/- 5.8 and 5.4 +/- 2.4 min after the injection, respectively. No changes in eye position or pupil diameter were observed in the control group. Akinesia was maintained for 44.3 +/- 26.7 min in the 1 mL-lidocaine group and for 88.5 +/- 17.2 min in the 2 mL-lidocaine group. Duration of mydriasis was 51.7 +/- 28.9 min in the 1 mL-lidocaine group and 82.9 +/- 15.6 min in the 2 mL-lidocaine group. Marked chemosis and sub-conjunctival haemorrhage occurred in 16/30 and 15/30 eyes, respectively. No significant change in IOP was observed between the mean pre- and post-injection values in all groups. These results suggest that a sub-Tenon's injection of 2 mL of 2% lidocaine provided effective extraocular muscle akinesia and mydriasis in dogs.

• 出版日期2013-4