THE EFFECT OF SUCCINYLCHOLINE ON THE ORBITAL MUSCULATURE OF THE CAT

SUMMARY With the use of new recording methods the effects of succinylcholine on the smooth musculature of the orbit were investigated in more than 30 cats anaesthetized with allobarbitone. The methods render it possible to study the retrobulbar smooth musculature of the nictitating membrane and the orbitin situ. Succinylcholine relaxes the smooth muscles in the orbit, and this results in a retraction of the eyeball together with a lateral movement of the nictitating membrane. The rise in intra‐ocular pressure under the influence of succinylcholine cannot be explained by any muscular factor in the orbit either from the striated or from the smooth extraocular muscles. In contrast to succinylcholine, curare does not produce retraction of the eyeball, lateral movement of the nictitating membrane or a rise in intra‐ocular pressure.