Retinal arterial macroaneurysms are acquired ectasias of the first 3 orders of retinal arterioles. Large macroaneurysms can actually traverse the full thickness of the retina. Vision loss may occur from embolic or thrombotic occlusion of the end arteriole (white infarct) or from sub–internal limiting membrane, intraretinal, subretinal, or vitreous hemorrhage, often in combination. Other retinal findings may include capillary telangiectasia and remodeling, as well as retinal edema and exudate involving the macula (Fig 6-22). Often, there are multiple arterial macroaneurysms, although only 10% of cases are bilateral. Arterial macroaneurysms are associated with systemic arterial hypertension in about two-thirds of cases and may occur in the area of previous vascular occlusions. Sclerosis and spontaneous closure often accompany macroaneurysm-related hemorrhage; bleeding more than once is rare.
Laser photocoagulation treatment may be considered if increasing edema in the macula threatens central visual function. In most instances, moderate-intensity laser treatment of the retina—performed immediately adjacent to the macroaneurysm using 2–3 rows of large-spot-size (200–500 μm) applications—results in closure. Some specialists prefer direct treatment. Caution should be used when treating macroaneurysms that occur in macular arterioles because a primary complication of the disease and its therapy is thrombosis with retinal arterial obstruction distal to the macroaneurysm. Anti-VEGF treatment has been reported to hasten resolution of macular edema from macroaneurysms without improving ultimate visual outcome.
Figure 6-22 Fundus photograph of a retinal arterial macroaneurysm with some exudate in the superior macula, resulting from leakage of the lesion, and mild hemorrhage.
(Courtesy of Colin A. McCannel, MD.)
Cho HJ, Rhee TK, Kim HS, et al. Intravitreal bevacizumab for symptomatic retinal arterial macroaneurysm. Am J Ophthalmol. 2013;155(5):898–904.
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Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.