Session: Poster session B

Evaluating Botulinum Toxin Injection to Treat VI Nerve Palsies : A Retrospective Study

INTRODUCTION 

Sixth nerve palsy (VI CNP) is a prevalent form of oculomotor paralysis associated with the risk of chronic diplopia. Botulinum toxin injections into the medial rectus muscle have been proposed to prevent complications, but their efficacy in acute VI CNP remains unclear.

 

METHODS 

This retrospective observational study, conducted between January 2018 and September 2022, aimed to compare the recovery rates of patients with acute VI CNP who received early medial rectus botulinum toxin injections to those who did not. Propensity score matching addressed inherent biases, considering factors such as age, gender, etiology, and initial deviation angle. Statistical analysis employed the Chi-square test.

 

RESULTS

Of the initially eligible 117 patients, 59 were excluded based on predefined criteria. Propensity score matching yielded two groups of 14 patients each. The recovery rate in the treated group was 75%, compared to 50% in the untreated group, although the difference was not statistically significant (p = 0.11). Transient side effects were observed in six patients, aligning with existing literature.

 

CONCLUSIONS

This study found no difference in long-term recovery between patients who received botulinum toxin injections and those who did not. However, the retrospective nature of the study does not allow us to conclude that there was no real lack of efficacy. In addition, further studies would be interesting to assess the effect on medial rectus contracture and the improvement in patients' quality of life after botulinum toxin injection. Finally, a randomised trial with a large number of patients is needed to determine the effectiveness of botulinum toxin in recovery and to better select the patients who would benefit most from it.