Lid retraction following blow-out fracture of the orbit.

A case of lid retraction following blow-out fracture of the orbit with enophthalmos is reported. This paradoxical complication has been described previously in only two cases, both by the same authors. It has been hypothesized that the lid retraction is secondary to Mueller's muscle overaction; however, excision of Mueller's muscle had no effect in this case. A new hypothesis is presented that this condition may be due to traction on the connective tissue sheath of the levator palpebrae muscle through its interconnections with the connective tissue systems of the other extraocular muscles.