|
Related Articles | ARMD, Exudative
Branch Retinal Vein Occlusion
Hemangioma, Capillary
Hemangioma, Cavernous
Macular Edema, Diabetic
Melanoma, Choroidal
Neovascular Membranes, Subretinal
Retinopathy, Diabetic, Background
Retinopathy, Diabetic, Proliferative
|
| Patient Education |
|
Click here for patient education.
|
|
You are in: eMedicine Specialties >
Ophthalmology > RETINA
Macroaneurysm
Article Last Updated: Jul 2, 2007
AUTHOR AND EDITOR INFORMATION
Section 1 of 11  
Author: Edward Chaum, MD, PhD, Professor and Director, Vitreoretinal Service, Plough Foundation Professor of Retinal Diseases, Department of Ophthalmology, Associate Professor of Pediatrics, Anatomy and Neurobiology, and Biomedical Engineering, University of Tennessee Health Science
Edward Chaum is a member of the following medical societies: Alpha Omega Alpha, American Academy of Ophthalmology, American Society of Retina Specialists, American Telemedicine Association, Association for Research in Vision and Ophthalmology, and Juvenile Diabetes Foundation International
Editors: Russell P Jayne, MD, Consulting Vitreoretinal Surgeon, The Retina Center at Las Vegas; Simon K Law, MD, PharmD, Assistant Professor of Ophthalmology, Jules Stein Eye Institute; Chief of Section of Ophthalmology Surgical Services, Department of Veterans Affairs Healthcare Center, West Los Angeles; Steve Charles, MD, Director of Charles Retina Institute; Clinical Professor, Department of Ophthalmology, University of Tennessee College of Medicine; Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri; Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Author and Editor Disclosure
Synonyms and related keywords:
retinal macroaneurysm, hypertension, macular hemorrhage, vitreous hemorrhage, retinal detachment, macular holes, choroidal neovascular membranes, choroidal neovascularization, decreased visual acuity, vision loss
Background
Retinal macroaneurysms are acquired, usually round, dilations of the large arterioles of the retina. Macroaneurysms are associated with systemic hypertension in approximately 75% of patients. They commonly are associated with macular exudation and hemorrhage, which may result in decreased visual acuity. A 10% incidence of bilateral disease exists, and multiple aneurysms in the same eye occasionally are seen.
Pathophysiology
Formation of retinal macroaneurysms is associated with systemic hypertension and atherosclerotic disease, but serum lipid abnormalities also have been reported. About 10% of patients have focal arterial wall atheroma occurring at defects in the wall, which may be sites at risk of aneurysm formation. The aneurysms are sites of leakage of exudates and hemorrhage in the macula. Over time or after acute hemorrhage, spontaneous thrombosis and closure of the aneurysm may occur; in some cases, the artery may return to normal.
Frequency
United States
Not reported
International
Not reported
Mortality/Morbidity
The visual prognosis in many patients is excellent, but vision loss that results from retinal macroaneurysm formation usually results from scarring in the macula due to either chronic edema or hemorrhage.
Race
No racial predilection exists.
Sex
The female-to-male ratio is 3:1.
Age
This condition occurs most commonly in the sixth to seventh decade. This condition is rare before age 60 years.
History
- Most patients present with sudden onset of painless vision loss in one eye.
-
- If the central macula is spared, the patient may be asymptomatic.
-
- Aneurysms that present without exudation or hemorrhage are asymptomatic.
-
Physical
- Aneurysmal dilation of the retinal arterioles occurs, usually at the site of vessel bifurcation or arteriovenous crossing in the major branch retinal arteries.
- The right eye more commonly is affected.
- The supertemporal artery most commonly is involved.
- Macroaneurysms also have been reported in cilioretinal arteries and on the optic nerve head.
- Occasionally, multiple aneurysms are present.
- Pulsatile flow occasionally is observed but does not necessarily indicate a higher risk of hemorrhage.
- Usually, leakage of protein-rich serum occurs, leading to circinate exudation and macular edema.
- Serous retinal detachment can occur.
- Bleeding is a common complication of aneurysm formation and can occur beneath the retina, the retinal pigment epithelium (RPE), the internal limiting membrane (ILM), or into the vitreous.
- Clinical complications of retinal macroaneurysms include vitreous hemorrhage, retinal detachment, macular holes, and choroidal neovascular membrane formation.
Causes
- The most commonly associated risk factor is hypertension.
-
- Generalized arterial sclerosis is a common feature.
-
- In some patients, serum lipid abnormalities have been reported.
-
- In some patients, the Valsalva maneuver may be associated with an increased risk of hemorrhage.
-
ARMD, Exudative
Branch Retinal Vein Occlusion
Hemangioma, Capillary
Hemangioma, Cavernous
Macular Edema, Diabetic
Melanoma, Choroidal
Neovascular Membranes, Subretinal
Retinopathy, Diabetic, Background
Retinopathy, Diabetic, Proliferative
Other Problems to be Considered
Radiation retinopathy
Leber miliary aneurysms
Lab Studies
- Blood pressure is likely to be elevated.
-
- Serum lipids may be elevated.
-
- Blood glucose is likely in the reference range. This test may be indicated to exclude undiagnosed diabetes in patients with exudative retinopathy in which the etiology is unclear.
-
Imaging Studies
- Fluorescein angiography is the most helpful imaging study for the diagnosis.
- Saccular dilation of the arteriolar wall is diagnostic of the disease.
- The angiogram is particularly important in making the diagnosis when hemorrhaging (which obscures the vasculature) occurs.
- Late fluorescein leakage from within the areas of hemorrhage is characteristic of the aneurysms and may assist in the diagnosis when the vasculature is not visible on direct examination.
Other Tests
- B-scan (and possibly A-scan) ultrasound may be indicated to rule out a choroidal mass or hemorrhagic retinal detachment in cases of hemorrhagic RPE detachment that may simulate a choroidal melanoma or a dense vitreous hemorrhage (which obscures visualization of the posterior pole).
Histologic Findings
Microvascular abnormalities (eg, widening of the periarterial capillary free zone, capillary dilation, nonperfusion, intra-arterial collaterals) have been identified. Histologic studies of the macroaneurysm show a break in the arterial wall, surrounded by a laminated layer of fibrin-platelet clot and blood. Lipid-laden macrophages, hemosiderin, and fibroglial reaction are also observed.
Medical Care
Control hypertension and serum lipids.
Surgical Care
- Laser photocoagulation
- The treatment of retinal macroaneurysms by direct laser photocoagulation is controversial.
- The natural history of the disease suggests that many patients have significant visual recovery without treatment.
- Treatment is generally recommended for persistent or progressive exudation in the macula.
- Moderately heavy argon green or yellow dye laser is used with large spot size (500 µm) and long duration (0.5 s).
- Direct treatment of the aneurysm is performed.
- Laser hyaloidotomy
- In the setting of dense subhyaloid hemorrhage, YAG laser hyaloidotomy has been performed to release the sequestered blood into the vitreous cavity.
- Release of blood that is sequestered over the macula may reduce the risk of macular scarring and epiretinal fibrosis. This procedure is controversial because of the risk of macular injury and vitreous hemorrhage.
- Surgical evacuation
- In rare settings where vitreous hemorrhage is present and the etiology of bleeding is unclear, vitrectomy surgery may be indicated. Removal of dense subretinal hemorrhage is very controversial and has the potential of causing many serious complications.
- The goal is to remove the extravasated blood and to assist in the diagnosis and possible treatment. Recently, pneumatic displacement of premacular hemorrhages using SF6 gas has also been reported.
Consultations
Medical workup if not previously diagnosed with hypertension
Diet
Per primary care provider
Activity
Reducing the risk of the Valsalva maneuver in patients with active pulsatile retinal macroaneurysms may be beneficial. However, this has not been proven to reduce the incidence of hemorrhages in these patients.
The primary care provider should control hypertension and serum lipids.
Further Outpatient Care
- Refer to the primary care provider for management of hypertension, if the patient is not already receiving care for this condition.
-
In/Out Patient Meds
- Control hypertension and serum lipid levels, per the primary care provider.
-
Complications
- Vision loss from macular edema due to chronic exudation is well documented in many patients.
- Laser treatment may be appropriate.
- Additional complications include risk of retinal and subretinal hemorrhage, vitreous hemorrhage, and epiretinal membrane formation.
- Complications also can occur from laser photocoagulation (see Medical/Legal Pitfalls).
Prognosis
- The visual prognosis is excellent for many patients.
- The natural history of macroaneurysms suggests that most close spontaneously with restoration of near normal vision.
- Chronic macular exudation and hemorrhage can lead to vision loss, which is an indication to consider laser photocoagulation.
- A study suggests that patients with preretinal hemorrhages or vitreous hemorrhages due to retinal macroaneurysms have a good visual prognosis; however, patients with submacular hemorrhages have a poor visual prognosis.
Medical/Legal Pitfalls
- No general consensus exists about laser treatment of retinal macroaneurysms.
- The natural history of the disease suggests that spontaneous closure is common. Treatment may not be indicated for most patients.
- The most frequently cited indication for laser photocoagulation of the macroaneurysm is persistence or progression of macular exudation. The current recommendation for photocoagulation of macroaneurysms is the use of the argon green or yellow dye laser for direct photocoagulation of the lesion. Some authors have recommended indirect treatment to minimize the risk of arteriolar occlusion and hemorrhage, but little rationale to this approach exists since the site of leakage is the macroaneurysm. Others recommend low power settings sufficient to create a light-to-moderate burn intensity, using large spot size (500 µm) and long duration (0.5 s) pulses directly to the lesion.
- Complications of laser treatment may include macular infarction from retinal arteriolar occlusion and laser-induced hemorrhage or retinal damage. Increased retinal exudation and scarring with subsequent retinal traction are also possible.
- Laser treatment may not improve the visual outcome, even when closure is successful, because of chronic edema and macular scarring.
| Media file 1:
Red-free photograph of left fundus of a 79-year-old woman presenting with decreased vision in left eye. This shows central macular exudation involving the fovea and intraretinal hemorrhages along the inferotemporal arcade. A whitish lesion is seen adjacent to the artery within the area of hemorrhage but is not well visualized. Visual acuity is 20/400. |
 |  View Full Size Image | |
Media type: Photo
|
| Media file 2:
Fluorescein angiogram during the venous phase demonstrating delayed filling of the retinal macroaneurysm with fluorescein dye. The aneurysm is obscured partially by the presence of hemorrhage, but filling by the dye enhances visualization. |
 | View Full Size Image | |
Media type: Photo
|
| Media file 3:
Fluorescein angiogram during the late phase showing complete filling of the retinal macroaneurysm with fluorescein dye. |
 | View Full Size Image | |
Media type: Photo
|
| Media file 4:
Fluorescein angiogram photograph taken 3 weeks after focal laser photocoagulation of the retinal macroaneurysm. Complete closure of the aneurysm is demonstrated. No embarrassment of arterial flow following treatment is present. The arterial lumen appears normal in the region of the aneurysm. Persistent macular edema is present. |
 | View Full Size Image | |
Media type: Photo
|
- Abdel-Khalek MN, Richardson J. Retinal macroaneurysm: natural history and guidelines for treatment. Br J Ophthalmol. Jan 1986;70(1):2-11. [Medline].
- Chaum E, Greenwald MA. Retinochoroidal anastomoses and a choroidal neovascular membrane in a macular exudate following treatment for retinal macroaneurysms. Retina. Jun 2002;22(3):363-6. [Medline].
- Ciardella AP, Barile G, Schiff W, Del Priore L, Langton K, Chang S. Ruptured retinal arterial macroaneurysm associated with a stage IV macular hole. Am J Ophthalmol. Jun 2003;135(6):907-9. [Medline].
- Fichte C, Streeten BW, Friedman AH. A histopathologic study of retinal arterial aneurysms. Am J Ophthalmol. Apr 1978;85(4):509-18. [Medline].
- Lavin MJ, Marsh RJ, Peart S, Rehman A. Retinal arterial macroaneurysms: a retrospective study of 40 patients. Br J Ophthalmol. Nov 1987;71(11):817-25. [Medline].
- Lewis RA, Norton EW, Gass JD. Acquired arterial macroaneurysms of the retina. Br J Ophthalmol. Jan 1976;60(1):21-30. [Medline].
- Mitamura Y, Miyano N, Suzuki Y, Ohtsuka K. Branch retinal artery occlusion associated with rupture of retinal arteriolar macroaneurysm on the optic disc. Jpn J Ophthalmol. Sep-Oct 2005;49(5):428-9. [Medline].
- Murhty K, Puri P, Talbot JF. Retinal macroaneurysm with macular hole and subretinal neovascular membrane. Eye. Apr 2005;19(4):488-9. [Medline].
- Panton RW, Goldberg MF, Farber MD. Retinal arterial macroaneurysms: risk factors and natural history. Br J Ophthalmol. Oct 1990;74(10):595-600. [Medline].
- Park SW, Seo MS. Subhyaloid hemorrhage treated with SF6 gas injection. Ophthalmic Surg Lasers Imaging. Jul-Aug 2004;35(4):335-7. [Medline].
- Perry HD, Zimerman LE, Benson WE. Hemorrhage from isolated aneurysm of a retinal artery: report of two cases simulating malignant melanoma. Arch Ophthalmol. Feb 1977;95(2):281-3. [Medline].
- Russell SR, Folk JC. Branch retinal artery occlusion after dye yellow photocoagulation of an arterial macroaneurysm. Am J Ophthalmol. Aug 15 1987;104(2):186-7. [Medline].
- Shults WT, Swan KC. Pulsatile aneurysms of the retinal arterial tree. Am J Ophthalmol. Mar 1974;77(3):304-9. [Medline].
- Tashimo A, Mitamura Y, Ohtsuka K, Okushiba U, Imaizumi H, Takeda M. Macular hole formation following ruptured retinal arterial macroaneurysm. Am J Ophthalmol. Apr 2003;135(4):487-92. [Medline].
- Tashimo A, Mitamura Y, Sekine N, Takeda M, Ohtsuka K. Rhegmatogenous retinal detachment after rupture of retinal arterial macroaneurysm. Am J Ophthalmol. Sep 2003;136(3):549-51. [Medline].
- Tassignon MJ, Stempels N, Van Mulders L. Retrohyaloid premacular hemorrhage treated by Q-switched Nd-YAG laser. A case report. Graefes Arch Clin Exp Ophthalmol. 1989;227(5):440-2. [Medline].
- Tonotsuka T, Imai M, Saito K, Iijima H. Visual prognosis for symptomatic retinal arterial macroaneurysm. Jpn J Ophthalmol. Sep-Oct 2003;47(5):498-502. [Medline].
- Townsend-Pico WA, Meyers SM, Lewis H. Indocyanine green angiography in the diagnosis of retinal arterial macroaneurysms associated with submacular and preretinal hemorrhages: a case series. Am J Ophthalmol. Jan 2000;129(1):33-7. [Medline].
Macroaneurysm excerpt Article Last Updated: Jul 2, 2007
|
