Abnormal chin up due to A pattern esotropia
One of the most valuable contributions in the second part of the twentieth century to the field of strabismus was the emphasis on what has come to be known as the A and V patterns of strabismus.
A pattern esotropia usually Associated with : Mongoloid Fissure , Medial Pulley down & Lateral Pulley up
The strabismus surgeon should be aware of the existence of pulleys. Although the surgeon will neither observe nor manipulate these structures they are an important factor in a proper diagosis in many cases
Surgery on the horizontal rectus muscles alone may effectively reduce vertical incomitance. Thus, when dysfunction of the oblique muscles is not evident. ttt of A pattern Et is :
Horizontal Surgery + MR upshift & LR down