The episcleral blood vessels may become dilated if certain conditions are present.
Conditions associated with dilated episcleral blood vessels:
(1) carotid-cavernous fistula
(2) cavernous sinus thrombosis
(3) untreated glaucoma
(4) hyperviscosity syndrome
(5) occlusion of the orbital veins at the apex of the orbit
(6) ophthalmic vein thrombosis
(7) tricuspid regurgitation
(8) uveal neoplasm with localized vascular engorgement
(9) chronic respiratory disease
