A Case of Idiopathic Dense Vitreous Hemorrhage: Suspected Rupture of a Large Retinal Arterial Macroaneurysm on the Optic Disc

We report a novel case of vitreous hemorrhage associated with suspected rupture of 2-disc-diameter retinal arterial macroaneurysm on the optic disc. A 90-year-old woman presented with blurred vision (sudden onset) in her left eye. Examination of the fundus revealed acute onset vitreous hemorrhage of unknown origin without retinal detachment. She underwent vitrectomy, but after excision of the dense vitreous hemorrhage, a 2-disc-diameter hematoma appeared on the optic disc and was removed promptly. Because the bleeding at the base of the hematoma was of arterial origin and pulsating, the first vitrectomy could not achieve hemostasis. Five days after the first surgery, we performed a second vitrectomy. This revealed a subretinal hemorrhage along the superior and inferior arcade vessels and a macular hole, which was almost completely closed with an inverted internal limiting membrane flap. Unfortunately, the macular hole reopened 41 days after the second surgery. In patients presenting with only a large hematoma on the optic disc, it might be prudent to leave the hematoma. However, this large retinal arterial macroaneurysm was on a rare location on the optic disc, making it doubly difficult for the surgeons to diagnose and choose the best option intraoperatively. The differential diagnosis for dense vitreous hemorrhage of unknown origin should include a large retinal arterial macroaneurysm on the optic disc.