First , you have to deal with what bothers the parents i.e the esotropia - in many cases like this I noticed that most parents are only aware of the horizontal deviation , this is really right , since the primary position is the most important cardinal direction to be respected , so first to be done here is BMR recession to correct the infantile esotropia

Then what about the bilateral limitation of elevation of the adducted eyes ?

This is a typical case of Bilateral Brown syndrome. Of course, this must be confirmed by demonstrating restricted forced ductions to elevation  in adduction

Second , You must think about the differential diagnosis of this condition :

Strabismus Course : Lecture 17 : Slide 51

You can simply exclude other causes since there is no history of trauma , of course this is not  a thyroid eye disease , also there is no history of previous strabismus or orbital surgeries , however IO palsy should be suspected since there is a history of other neurological disorders together with the facial asymmetry and the abnormal head circumference 

See Forced duction Test in this patient

Based on the typical appearance, it is safe to schedule surgery with confidence that the diagnosis of Brown will be confirmed. The choice of surgical procedure depends on the experience and the preference of the surgeon.

1) The first surgical procedure is :

      Expose the entire superior oblique tendon after a ‘cuffed’ superior limbal      incision, usually with detachment of the superior rectus . explore the superior oblique tendon from the trochlear cuff to the tendon's insertion freeing any obvious restrictions , replace the superior rectus and close.