Ptosis caused by orbicularis myokymia and treated with botulinum toxin

A 23-year-old systemically healthy lady presented with
complaints of ptosis of the left upper eyelid, present
persistently since 3 months.
On examination, the best-corrected visual acuity was
6/6, in both eyes. The left upper eyelid was 1 mm lower
in position and the lower eyelid was 1 mm raised,
compared to the right eye. There was increased tone
noted in the lower eyelid pretarsal orbicularis (Figure 1a).
The left upper eyelid showed the presence of constant,
rhythmic, fibrillations. The ptosis was constant, on

evaluation on three different days, for an hour each. Post-
closure, the upper eyelid was also slower to open. The

levator action was 15 mm and the lid crease height was
8 mm, in both eyes. Remaining ocular examination was
unremarkable.
Magnetic resonance imaging of the central nervous
system was unremarkable. Special attention was paid to
the VII nerve complex and the cerebropontine angle to
rule out a dolichoectatic basilar vessel compression on
the VII nerve, as a possible cause. Electro-myography of
the left orbicularis muscle was performed and
demonstrated over-activity (Figure 1b).

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