Role of inferior rectus botulinum toxin injection in iatrogenic vertical strabismus.

INTRODUCTION

We describe the uses and effectiveness of botulinum toxin to the inferior rectus muscle in iatrogenic vertical strabismus.

METHODS

A retrospective review of our database to identify patients who had undergone inferior rectus botulinum toxin injection between 1982 and 2006 for iatrogenic vertical strabismus.

RESULTS

There were 13 patients, 5 female, with an age range of 14 to 78 years. Eight left eyes were injected. The mean period of follow-up was 3.3 years. Etiologies included post-local anesthetic, post-plaque radiotherapy for malignant melanoma, adherence syndrome after inferior oblique surgery, and post-botulinum toxin to the levator muscle to produce a temporary therapeutic ptosis. Reversal on first injection occurred in 7 patients and occurred in a further 2 patients on second injection. Pre-injection binocularity was not demonstrable in 3 patients; 2 of these patients did have binocular vision demonstrable after botulinum toxin injection. Seven patients had one injection, 3 patients had two, 1 had three, 1 had five, and 1 had six.

DISCUSSION: The data demonstrate the range of indications that can be successfully treated and managed with inferior rectus botulinum toxin injection in iatrogenic vertical strabismus.