Most common cause of proptosis in adults is
(Refer: AK Khurana Comprehensive Ophthalmology, 6th edition, pg no. 403 - 407)The most common cause of unilateral proptosis in children is orbital cellulitisThe most common cause of unilateral proptosis in adults is thyroid ophthalmopathy
Orbital cellulitis
Thyroid ophthalmopathy
Carotico-cavernous fistula
Trauma
Ocular trauma 