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This 42-year-old woman underwent ethmoid sinus surgery 2 ½ months ago. Immediately after surgery she noted a large XT and presented for an eye examination. Except for the motility that can be observed in the pictures, the eye examination was normal. The patient has double vision, but the images are so far apart that the double vision is not a big problem. She complains of her appearance and the inability to adduct the right eye. As can be seen in the pictures her eyes are close to alignment in right gaze but in all other positions a large exotropia is noted, increasing to a maximum in left gaze.

1.	Upon taking the history and observing the patient initially you conclude:
	c -- This condition could be related to the sinus surgery. It is probable that during the surgery on the ethmoid sinus, the rotating tissue remover used by the surgeon to clean out the sinus went through the thin medial wall, entering the orbit. Once in the orbit, the rotating cutting tool “chewed up” the medial rectus that lies along this thin wall that separates the orbit from the sinus.  Since its first use more than 20 years ago, this type of instrument has caused this to happen many times, I have seen it several times. (EMH)
2.	Given that the eye examination is normal, what would be a good test to order:
	d -- imaging of the orbit Once the eye examination has been completed in the clinic, normal in this patient except for the motility, the next thing to do is obtain imaging of the orbit.  It is common for cases like this to come to litigation so it is especially important to have documentation even if clinically you are sure of the diagnosis.  This imaging also tells you how much of the muscle is gone, helping decide on the type of surgery.  As you can see in the MRI, a large portion of the right medial rectus is missing.  The radiologist estimates 16 mm. (See the MRI)
3.	The patient asks you what she can expect in the way of needed treatment to “fix” her eyes.
	a -- surgery In a case like this surgery is indicated.  Too much medial rectus is gone to have any chance to reunite the cut ends.  This means that a muscle transfer is indicated.  It would be nice to recess the lateral rectus before doing a vertical rectus transfer to the medial rectus.  But this would invite anterior segment ischemia with all anterior ciliary arteries cut.  Alternatives would be the following: 1. Botox to the lateral rectus and full tendon transfer of the vertical recti to the area of the medial rectus insertion. The Botox could be given first. When the lateral rectus is paralyzed, the muscle transfer could be done.  This leaves one anterior ciliary artery remaining intact.  2. Recess the lateral rectus and transfer the medial half of the vertical recti to the medial rectus insertion.  If done so as to preserve the medial anterior ciliary arteries in the vertical recti, two anterior ciliary arteries should remain.  3. It is also possible to pull the nasal half of the bellies of the vertical recti toward the medial rectus insertion without disinserting them, while placing them as close as can be done, thereby changing the pull of the muscles without cutting the anterior ciliary arteries.  This can be done with or without recessing the lateral rectus or with Botox in the lateral rectus.   (See Surgical Management of Strabismus, page 270.)