Traumatic eye with late presentation of hyperaemic sclera with unilateral proptosis is due to -

Retrobulbar hematoma usually presents with a history of trauma, painful exophthalmos (proptosis), retriction of extraocular movement, diffuse subconjunctival hemorrhage, periorbital edema and ecchymosis. Retrorbital abscess develops as a complication of orbital cellulitis (there is no history of symptoms of orbital cellulitis in this question). Carotico-covernous fistula typically presents, days or weeks after the trauma. There is characteristic pulsatile exophthalmos with severe and sudden cephalic & orbital pain, a roaring sound in head synchronous with the pulse, decreased vision, diplopia and ophthalmoplegia. Sorry friends, I could not get the reference for pneumo-orbit.