Abducens nerve palsy after orbital decompression

Double vision after decompression surgery for Thyroid Eye Disease (TED) is well described in the literature and the incidence ranges from 0 to 64%. The Mechanisms for new onset diplopia after orbital decompression are poorly understood. Common theories include: Fibrosis of muscles, displacement of the muscle cone, and reactivation of the TED.We present two cases with Abducens nerve palsy after uncomplicated secondary orbital decompression surgery.Two patients with inactive TED, who were followed for an average of 2 years prior to uneventful secondary decompression surgery, presented at the first postoperative visit with double vision and limitation of abduction in the recently operated eye. Magnetic resonance imaging(MRI) was done in both cases and revealed no abnormal bleeding or scaring.Our two cases of Abducens palsy following reoperative orbital decompression may be due to ischemic neuropathy caused by postoperative hemorrhage or inflammation.