Macroaneurysm

Carl D. Regillo


BASICS


DESCRIPTION


• 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).


EPIDEMIOLOGY


• Macroaneurysms may be bilateral in one-fifth of patients.


• Multiple macroaneurysms may be present in about 10% of patients.


RISK FACTORS


• Systemic hypertension (75%)


• Atherosclerotic cardiovascular disease


• Hyperlipidemia


• Age (most patients > 60 years)


• Sex (60–80% female)


• Retinal vein occlusions (12× higher prevalence of macroaneurysm in area drained by occluded vein)


GENERAL PREVENTION


Strict medical management of systemic hypertension


PATHOPHYSIOLOGY


• 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


ETIOLOGY


See “Risk Factors.”


COMMONLY ASSOCIATED CONDITIONS


See “Risk Factors.”


DIAGNOSIS


HISTORY


• 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.


PHYSICAL EXAM


• 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


– Intraretinal


– Preretinal


– Vitreous


DIAGNOSTIC TESTS & INTERPRETATION


Imaging


• 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


Diagnostic Procedures/Other


Check blood pressure


Pathological Findings


• Gross: Distention of the retinal arteriole


• Microscopic: Fibroglial proliferation, deposits of hemosiderin, lipoidal exudates, extravasated blood


DIFFERENTIAL DIAGNOSIS


• 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


TREATMENT


Observation hemorrhage or in the absence of vision loss


SURGERY/OTHER PROCEDURES


• Laser photocoagulation (24)[B]:


– 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.


ONGOING CARE


FOLLOW-UP RECOMMENDATIONS


• Retina specialist


• Primary care physician for evaluation and management of associated systemic risk factors (See “Risk Factors”)


PATIENT EDUCATION


Macroaneurysm: eMedicine Ophthalmology (emedicine.medscape.com/article/1224043-overview)


PROGNOSIS


• 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.


COMPLICATIONS


• Vision loss related to the following:


– Macular scarring secondary to hemorrhage or chronic edema


– Vitreous hemorrhage


– Retinal detachment



REFERENCES


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.

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Nov 9, 2016 | Posted by in OPHTHALMOLOGY | Comments Off on Macroaneurysm
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