Spontaneous Orbital Hemorrhage Related to the Extraocular Muscles

The authors present the largest series of patients to date of spontaneous hemorrhage in relation to extraocular muscles (EOMs).

Observational retrospective case series. Institutional review board approval was obtained.

Eighteen patients with a mean age of 71 years presented with 20 episodes of spontaneous orbital hemorrhage closely related to an EOM. Most patients woke with unilateral proptosis, pain, and diplopia. Vision was impaired in 25%. Imaging identified a characteristic well-circumscribed hematoma arising within the muscle sheath or intermuscular septum. Three episodes required surgical drainage. All patients had good recovery of vision.

The authors describe a distinct clinical entity of idiopathic hemorrhages related to EOMs. No patient had an underlying vascular malformation or other lesion. The authors demonstrate that a proportion of these patients have vascular risk factors, namely, hypertension, hyperlipidemia, and antiplatelet use. This study suggests that inferior rectus is the most commonly affected EOM and shows that it is the muscle sheath or intermuscular septum of inferior rectus that is involved, rather than the muscle belly. Most patients can be managed conservatively with good visual outcomes. However, there were 3 exceptional cases that required surgical intervention.

The findings that spontaneous orbital hemorrhages related to EOMs have certain predisposing factors, a characteristic radiological appearance, and a typically benign course will be helpful for clinicians in the management of this condition.