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This 5-year-old girl was noted by her parents to have misaligned eyes since age 6 months. The child is now and has been in good health. There is no family history of strabismus. Eye examination revealed cycloplegic refraction of OD +1.00 sphere and OS +0.50 +0.50 X 90. This girl in casual seeing tilted her head to the left as seen in picture 15. She has facial asymmetry, with the larger face on the right. This finding and a drooping of the right upper lid with right hypotropia are seen in picture 14 (note full excursion of the right upper lid in several other pictures). She prefers fixation with the left eye in spite of acuity reported at 20/50 compared to 20/20 in the right eye. She has a left hypertropia greater in right gaze with overaction of the left inferior oblique and a greater hyperdeviation in left head tilt. Some limitation of downgaze in the left eye is noted (best seen in picture 8).

1.	The motility diagnosis is:
	b -- left superior oblique palsy This is clearly a case of left superior oblique palsy based on the left hyper being greater in right gaze and with left head tilt.  There is also some limitation of depression making this likely to be a class IV left superior oblique palsy. (For more information go to E-Learning and register for the course on Superior Oblique Palsy: ST-11.05.)
2.	The right lower lid being down in picture 14 is related to:
	e -- more than one of the answers above There are three answers among the options presented that are correct. This girl has a pseudoptosis of the right upper lid present when she fixes with her paretic left eye. Extra innervation required by the paretic left superior oblique is sent to the yoke right inferior rectus according to Hering’s law of distributed innervation.  The right superior rectus and levator are inhibited then, in compliance with Sherrington's law of reciprocal innervation.
3.	Based on the diagnosis, the facial asymmetry in this case is:
	e -- none of the above This asymmetry of the face is not what would be typically seen with a left superior oblique palsy where the head tilt would be to the right to put the eyes out of the field of action of the paretic muscle, and the larger face would be on the left.  While facial asymmetry is seen with head tilt, this head tilt is atypical for the diagnosis.  This kind of facial asymmetry is not reversible after a certain age, probably not more than +/- 12 months.  This atypical facial asymmetry is a very significant finding in that it confirms that the facial asymmetry is simply on the basis of the head posture and is not related specifically to the neurological deficit. (To learn more about facial asymmetry and strabismus go to the E-Learning certificate ST-11.00 on the Superior Oblique.)