Spontaneous involution of a large retinal arterial macroaneurysm

. Background: Acquired retinal macroaneurysms are round dilatations of retinal arterioles that occur in the posterior fundus. They tend to rupture before they grow large and cause a visual decrease. The average diameter of macroaneurysms in the previous reports is 281 micrometer. Methods: A 63-year-old man complained of a sudden decrease of visual acuity in the left eye. Fundus examination of his left eye revealed a large protruded mass, 2 disc diameters in size, at the first bifurcation of the inferotemporal retinal artery. Preretinal vitreous bleeding and serous retinal detachment were observed around the lesion. Indocyanine green (ICG) angiography showed this mass to be continuous with the inferotemporal retinal artery and ICG dye leaked from the retinal artery into the lumen of the mass, with pulsation. Results: Six months later, the large macroaneurysm underwent spontaneous involution. Conclusion: As shown in this patient, retinal macroaneurysms may grow extremely large. ICG angiography was useful to diagnose this large retinal arterial macroaneurysm.