Carl D. Regillo
• Acquired retinal macroaneurysms are focal saccular or fusiform dilations of retinal arterioles within the first three orders of branching of the arteriolar system:
– Typically located at arteriovenous crossings or arteriolar bifurcations
– The superotemporal arteriole is the most commonly reported site of involvement (due to its proclivity for visual impairment).
• Macroaneurysms may be bilateral in one-fifth of patients.
• Multiple macroaneurysms may be present in about 10% of patients.
• Systemic hypertension (75%)
• Atherosclerotic cardiovascular disease
• Age (most patients > 60 years)
• Sex (60–80% female)
• Retinal vein occlusions (12× higher prevalence of macroaneurysm in area drained by occluded vein)
Strict medical management of systemic hypertension
• Inelasticity of retinal arterioles secondary to the effects of aging, hypertension, and atherosclerotic disease predisposes to dilatation and formation of a macroaneurysm, of which there are 2 classical types (2)[C].
– Saccular (group 1): Characterized by acute decompensation with a variable degree of intraocular hemorrhage
– Fusiform (group 2): Characterized by chronic exudation of plasma constituents
See “Risk Factors.”
COMMONLY ASSOCIATED CONDITIONS
See “Risk Factors.”
• Painless vision loss; onset may be acute or subacute depending on the type of macroaneurysm.
– Macroaneurysms without any exudation or hemorrhage are asymptomatic and usually found incidentally.
• Macroaneurysm is evident on clinical ophthalmoscopic exam; pulsatile flow may be observed.
• Multiple macroaneurysms may be present on rare occasion.
• Serous retinal detachment, lipid exudation, and/or macular edema may be present.
• Hemorrhage may occur at various levels:
– Subretinal and subretinal pigment epithelium
DIAGNOSTIC TESTS & INTERPRETATION
• Fluorescein angiography (FA):
– Focal, uniform filling in the early arterial phase
– Leakage of surrounding dilated capillaries
• Indocyanine green (ICG) angiography:
– Useful for establishing the diagnosis in the setting of sub- or premacular hemorrhage; longer wavelength
• Optical coherence tomography:
– May be useful in cases with chronic exudation to track changes
Check blood pressure
• Gross: Distention of the retinal arteriole
• Microscopic: Fibroglial proliferation, deposits of hemosiderin, lipoidal exudates, extravasated blood
• Retinal vascular abnormalities and diseases:
– Diabetic retinopathy
– Retinal capillary hemangioma
– Retinal venous occlusive disease
– Retinal telangiectasis
– Retinal cavernous hemangioma
– Hemorrhagic pigment epithelial detachment of age-related macular degeneration
– Polypoidal choroidal vasculopathy
Observation hemorrhage or in the absence of vision loss
– For exudation that threatens or involves the fovea in the absence of hemorrhage that would preclude laser
– Low intensity, longer duration argon green or yellow laser to microvascular changes surrounding the leaking aneurysm
– Direct treatment of the aneurysm remains controversial (may in theory result in vitreous hemorrhage or branch retinal artery occlusion and distal ischemia).
• Pars plana vitrectomy:
– To clear vitreous hemorrhage
– For recent (<1 week) massive subfoveal hemorrhage, surgical evacuation with subretinal injection of tissue plasminogen activator has been described.
• Retina specialist
• Primary care physician for evaluation and management of associated systemic risk factors (See “Risk Factors”)
Macroaneurysm: eMedicine Ophthalmology (emedicine.medscape.com/article/1224043-overview)
• The visual prognosis may be variable (2)[B]:
– Macular hemorrhage or chronic edema may result in decreased visual acuity.
– Spontaneous thrombosis and involution may occur, leaving a vessel kink overlying a pseudodisciform plaque.
– Artery may in some cases return to normal.
• Vision loss related to the following:
– Macular scarring secondary to hemorrhage or chronic edema
– Vitreous hemorrhage
– Retinal detachment
1. Panton RW, Goldberg MF, Farber MD. Retinal artery macroaneurysm: Risk factors and natural history. Br J Ophthalmol 1990;74(10):595–600.
2. Abdel-Khalek MN, Richardson J. Retinal macroaneurysm: Natural history and guidelines for treatment. Br J Ophthalmol 1986;70(1):2–11.
3. Brown DM, Sobol WM, Folk JC, et al. Retinal arteriolar macroaneurysms: Long term visual outcome. Br J Ophthalmol 1994;78:534–538.
4. Rabb MF, Gagliano DA, Teske MP. Retinal arterial macroaneurysms. Surv Ophthal 1988;33:73–96.