Temporal branch retinal vein obstruction masquerading as a retinal arterial macroaneurysm: the Bonet sign.

We present the case report of a patient with a hemorrhage at an arteriovenous crossing which was erroneously interpreted as being an arterial macroaneurysm. Shortly thereafter, the typical appearance of a temporal branch retinal vein obstruction was evident indicating that the hemorrhage was an early sign of the venous obstruction. This sign (the Bonet sign) should alert the clinician to this disorder so that the correct diagnosis and recommendations for patient care can be undertaken.