Acquired retinal macroaneurysm

From EyeWiki
Original article contributed by: Sharon Fekrat, MD
All contributors: Brad H. Feldman, M.D., Sharon Fekrat, MD and Vinay A. Shah M.D.
Assigned editor: Peter A.Karth, MD
Review: Assigned status Update Pending by Brad H. Feldman, M.D. on December 24, 2014.



Disease Entity

Etiology

An acquired retinal macroaneurysm forms when arteriosclerosis leads to weakening of the arteriolar wall and consequently, the arterial wall develops an outpouching that results in a macroaneurysm.

Risk Factors

Systemic hypertension, cardiovascular disease, and hyperlipidemia are risk factors for acquired retinal macroaneurysm formation. Females are more likely to be affected in their sixth or seventh decade.

General Pathology

Histopathologically, there is distension of the affected arteriolar wall, often with surrounding lipid, hemosiderin, blood and proliferation of fibroglial cells.

Diagnosis

History

There may be no symptoms at all in an eye with an acquired retinal macroaneurysm that has not bled or leaked into the macula. In some eyes, there may be sudden painless loss of vision.

Physical examination

A complete ophthalmologic examination with pupillary dilation should be performed.

Symptoms

The patient may be asymptomatic or may notice a painless sudden decrease in vision.

Clinical diagnosis

On ophthalmoscopy, fusiform or round outpouchings or dilations may be evident along one of the retinal arterioles. About 90% are unilateral. The macroaneurysm is usually located in the posterior pole at one of the first 3 bifurcations of the retinal arterioles, with the superotemporal artery being the most common. In some eyes, multilayer hemorrhage is often noted----subretinal, subhyaloid/preretinal, intraretinal and vitreous hemorrhage may be present, obscuring the macroaneuyrsm itself. These locations of hemorrhage is characteristic in eyes with an acquired retinal macroaneurysm that has bled. If a vitreous hemorrhage is present, Bscan ultrasonography may demonstrate the multilayer hemorrhage as well.

Diagnostic procedures

Fluorescein angiography can be very useful in making the diagnosis, particularly in those eyes that have associated hemorrhage where the macroaneurysm may light up with the fluorescein where the macroaneurysm usually fills in the early arterial phase. In the late phase frames, the wall of the aneurysm may demonstrate leakage or staining. However, in some eyes, the blood is so extensive that the macroaneurysm is not visible even on fluorescein angiography since the blood blocks the fluorescence.

Laboratory test

Patients with an acquired retinal macroaneurysm should have a lipid panel evaluated by their internist as well as a blood pressure evaluation.

Differential diagnosis

The following entities should be considered in the differential diagnosis of acquired retinal macroaneurysm when associated with hemorrhage: branch retinal vein occlusion, retinal telangiectasis, proliferative diabetic retinopathy, neovascular age-related macular degeneration when associated with hemorrhagic pigment epithelial detachment.

Management

General treatment

Instruct the patient to followup with the patient's internist to monitor and treat blood pressure and any lipid abnormalities. Smoking should be discouraged.

Surgery

Laser photocoagulation

Complications

Complications related to the presence of the retinal macroaneurysm include lipid deposition in the foveal center, macular edema, subfoveal hemorrhage, and vitreous hemorrhage.

Additional Resources

  • AAO, Basic and Clinical Science Course, Section 12: Retina and Vitreous, 2010-11.
  • American Academy of Ophthalmology. Refractive Management/Intervention: Acquired retinal macroaneurysm Practicing Ophthalmologists Learning System, 2017 - 2019 San Francisco: American Academy of Ophthalmology, 2017.