Session: Poster session C

Effect and duration of diagnostic injection of lidocaine into extraocular muscles

Introduction: Lidocaine injection into extraocular muscles induces a temporary paralysis which may be useful in clinical practice. It may be used as an alternative to the use of botulin toxin injection, which has a longer lasting effect and more side effects, as a diagnostic procedure to evaluate complicated diplopias.

 

Methods: Description of 3 cases of perimuscular lidocaine 2% injection into extraocular muscles focusing on obtaining a time-effect curve and diagnosis of diplopias with uncertain prognosis after surgery.

 

Results: Description of 3 cases of diplopia which was not entirely compensated by prisms. Two out of three cases had a great symptomatic improvement which was followed by a good surgical result as well as a correction of the asthenopia which was the main symptomatic complain. The time-curve effect showed a possible maximum effect between 4-6 hours after injection and a complete effect cessation 24 hours after injection. 

 

Conclusion: In conclusion, lidocaine is considered as a promising diagnostic procedure useful for complex cases. In our clinical practice a good correlation between lidocaine effect and an adequate surgical result was found. It has a fast and reversible effect in less than 24 hours with a probable maximum effect between 4 and 6 hours. Further investigation is required to improve our understanding of lidocaine effect and establish the best moment to examine the patient to acquire the best clinical information.