The anatomical location and laterality of orbital cavernous haemangiomas.

Purpose: To determine the anatomical location and laterality of orbital cavernous haemangiomas (OCH).

Design: Retrospective case series.

Methods: The records of 104 patients with OCH were analyzed.

Main Outcome Measures: The anatomical location of each OCH defined by the location of a point at the centre of the lesion, and its laterality.

Results: There were 104 patients included in the study. No patient had more than one lesion. Sixteen (15.4%) were located in the anterior third of the orbit, 74 (71.2%) were in the middle third, and 14 (13.5%) in the posterior third. In the middle third, 10 of 74 (13.5%) were extraconal and 64 intraconal (86.5%), with 30 of 64 (46.9%) middle third intraconal lesions lying lateral to the optic nerve. Of 104 lesions, 56 (53.8%) were left sided, showing a trend towards a predilection for the left side (p = 0.065). If data from other published series which included data on laterality is added to our own data and analysed, 270 of 468 (57.7%) OCH occurred in the left orbit (p < 0.005).

Conclusions: OCH may occur at almost any location within the orbit. The commonest location is the middle third of the orbit, in the intraconal space lateral to the optic nerve. This may reflect an origin of these lesions from the arterial side of the circulation, as there are more small arteries in the intraconal space lateral to the optic nerve than in other locations. A predilection for the left orbit remains unexplained.