Unilateral proptosis with bilateral VI
th
 nerve palsy,diagnosis is -
Unilateral proptosis and bilateral 6th nerve polsy suggest the diagnosis of CST.
Bilateral 6th nerve palsy suggests the involvement of opposite side cavernous sinus. In more than 50% of the patients of CST opposite side is involved. 6th nerve is earliest to be involvement.
Grave's disease
Retinoblastoma
Pseudotumour of orbit
Cavernous sinus thrombosis