AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Retinal vein occlusion (RVO) has been recognized as a distinct entity for quite some time. In 1854, Leibreich described it as "retinal apoplexy," and Leber soon after in 1877 called it "haemorrhagic retinitis" based on its common retinal findings.

Even today, the current understanding of the disease and its treatment is still evolving. From the perspective of emergency medicine, it is useful to conceptualize RVO as being composed of two distinct entities. The two entities have different etiologies, presentations, and ultimate outcomes. When a patient is referred for further evaluation and treatment by an ophthalmologist much of the ophthalmologist's initial work will be done to discern the two. Further separating RVO into a more elaborate framework depending on the vein affected is possible but that is more the realm of ophthalmology, and whether this detail is helpful to an emergency physician in the conceptualization, evaluation, treatment, and ultimate referral of RVO from the emergency department is debatable.

Retinal vein occlusion (RVO) can be separated into the following categories:

• Nonischemic RVO (venous stasis retinopathy) is potentially benign and self-limited with usually a good visual outcome.
• Ischemic RVO (hemorrhagic retinopathy) carries a poor visual prognosis. Ischemic RVO accounts for a quarter of RVO cases overall.

Pathophysiology

Tendency for RVO can be remembered by recalling Virchow's triad.

• Stasis in the blood (eg, external compression, hypotension)
• Damage to the vessel wall (eg, phlebitis, inflammatory diseases)
• Increased tendency of the blood to form thrombus eg, (factor deficiencies, hypercoagulable states)

Most researchers believe the pathogenesis is multifactorial. The most common associated diseases are hypertension, diabetes mellitus, and atherosclerotic heart disease. Patients with glaucoma have a 5 times more likely chance of developing RVO than patients without glaucoma.

Frequency

United States

RVO is the second most common retinal vascular disorder after diabetic retinopathy; however, exact frequencies are not known.

International

International incidence is not known.

Mortality/Morbidity

• Ischemic RVO has significant complications.
• Nonischemic RVO usually has a good prognosis and outcome unless the macula is involved, though a third of cases may convert to ischemic RVO within 4 years.
• Mortality and morbidity may occur secondary to the underlying pathology.

Race

Little documentation exists regarding race and RVOs; however, they are thought to be rare in the Asian and West Indian populations.

Sex

Reportedly, all clinical categories are slightly more common in men than in women except major branch retinal vein occlusion (BRVO).

Age

Reported cases occur in those aged from 8 months to 92 years. More than one half of cases occur after the age of 65.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• Patients with nonischemic RVO may present much more subtly than those with ischemic RVO. Retinal hemorrhages may be found incidentally on funduscopic examination without visual complaint, or patients may complain of increasing blurry vision, usually worse in the morning upon waking and improving throughout the day. Diurnal variations in blood pressure are thought to account for this, with relative nighttime hypotension able to lead to decreased retinal vein blood flow. The history may be progressive, because of increasing macular edema, and blurry vision may be preceded by episodes of amaurosis fugax.
• Ischemic RVO presents with an acute decrease in visual acuity.

Physical

• Retinal hemorrhages may not be present for several days or if present may be difficult to visualize in the ED with direct ophthalmoscopy. Peripheral hemorrhages tend to be the first to appear and may only be visible with indirect ophthalmoscopy.
• Cotton wool spots represent deeper focal retinal ischemia.
• An afferent pupillary defect may be noted.
• Visual field cuts may be noted.
• Markedly decreased visual acuity tends to be more common in ischemic RVO. In one study, a visual acuity of 20/200 or better was seen in 80.9% of nonischemic cases and in only 6.7% of ischemic RVO.
• Swollen optic disc may be seen.
• Dilated, tortuous retinal veins may be present.

Causes

• Local disease processes include the following:
• • Trauma
  • Open- and closed-angle glaucoma
  • Orbital abscesses
  • Orbital tumors
  • Vascular hypertension
• Systemic disease processes include the following:
• • Diabetes mellitus
  • Hypertension
  • Arteriosclerosis
  • Hyperviscosity syndromes (neoplasms, polycythemia vera, sickle cell anemia)
  • Coagulation disorders (antithrombin III deficiency, antiphospholipid antibodies, activated protein C resistance)
  • Dehydration
  • Cocaine use
  • Sickle cell anemia
  • Vasculitis
  • Renal insufficiency
  • Dysproteinemias

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Amaurosis fugax
Eclipse burn
Hysterical blindness (functional blindness)
Ophthalmic migraine
Retrobulbar neuritis

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• The most essential element is emergent ophthalmologic consultation and follow-up. The extent of the initial ED workup should be dictated by the practice setting.
• For a patient with retinal artery occlusion, target laboratory testing to uncover underlying medical conditions.
• • Initial testing may include a complete blood count (CBC) and a coagulation profile to evaluate for a blood dyscrasia.
  • Electrolytes, blood urea nitrogen (BUN), creatinine, and serum glucose measurements also are recommended to explore the possibility of diabetes mellitus, renal disease, or dehydration.
  • An erythrocyte sedimentation rate (ESR) may be helpful in detecting inflammatory causes.
  • A lipid profile may reveal an underlying hyperlipidemia.
  • In the appropriate clinical context, a sickle cell preparation or urine drug screen could be helpful.

Imaging Studies

• Obtaining a chest radiograph for a complete initial evaluation is recommended. However, this may not be necessary during the initial ED evaluation.

Other Tests

• Focus other testing on specific ophthalmic evaluation.
• • Visual acuity is mandatory in virtually all instances.
  • Initially consider at least a gross evaluation of visual fields. Formal testing can follow at a later point.
  • Tonometry is useful.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Emergency Department Care

No effective, reliable treatment is available. Several treatments have been advocated in the past; however, many were not based on scientific evidence and may represent only normal resolution of nonischemic RVO. Treatments that may be considered from the ED after consultation with an ophthalmologist are use of systemic corticosteroids, treatment of elevated intraocular pressure, and use of acetazolamide.

• Systemic corticosteroids are the only therapy shown to reduce macular edema in nonischemic RVO. Not all patients will respond. Patients with vasculitis may show marked improvement.
• Lower intraocular pressure if elevated with the typical agents used for glaucoma (see Medications Carbonic anhydrase inhibitor, Beta-blockers and Miotics).
• In nonischemic RVO, some patients on acetazolamide will have decreased macular edema as long as they remain on the medication.
• Photocoagulation is currently the treatment of choice. However, considerable debate continues regarding whom the treatment may benefit.
• Anticoagulants, antiplatelet agents, fibrinolytics, and thrombolytics have no therapeutic value and may be harmful.
• Other therapies that have been used but found to be ineffective include surgical decompression, low molecular weight dextran, hemodilution, and carbon dioxide inhalation.

Consultations

Ophthalmologic consultation is mandatory. Management is outside the scope of emergency medicine.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

The goal of therapy is to reduce macular edema and lower intraocular pressure if elevated.

Drug Category: Corticosteroids

These agents have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.

Drug Category: Carbonic anhydrase inhibitor

An enzyme found in many tissues of the body, including the eye, which catalyzes a reversible reaction that involves the hydration of carbon dioxide and the dehydration of carbonic acid.

Slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport may inhibit CA in the ciliary processes of the eye. This effect decreases aqueous humor secretion, reducing the intraocular pressure.

Drug Name	Dorzolamide (Trusopt)
Description	Use concomitantly with other topical ophthalmic drug products to lower intraocular pressure. If more than one ophthalmic drug is being used, administer the drugs at least 10 min apart.
Adult Dose	1 gtt in affected eye or eyes tid
Pediatric Dose	Not established
Contraindications	Documented hypersensitivity; hepatic disease; severe renal disease; adrenocortical insufficiency; severe pulmonary obstruction
Interactions	Can decrease therapeutic levels of lithium and alter excretion of drugs (amphetamines, quinidine, phenobarbital, salicylates) by alkalinizing urine
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Patients with impaired hepatic function may go into coma; may cause substantial increase in blood glucose in some diabetic patients

Drug Category: Beta-blockers

Timolol, levobunolol, carteolol, betaxolol, and metipranolol are topical beta-blockers that reduce elevated and normal intraocular pressure, with or without glaucoma. The immediate objective in angle-closure glaucoma is to reopen the angle, requiring constriction of the pupil with a miotic. These agents have little or no effect on the pupil. When they are used to reduce elevated intraocular pressure in angle-closure glaucoma, they should be used concurrently with a miotic. The exact mechanism of ocular antihypertensive action is not established, but it appears to be a reduction of aqueous production. However, some studies show a slight increase in outflow facility with timolol and metipranolol.

Drug Name	Levobunolol (Betagan, AKBeta)
Description	Nonselective beta-adrenergic blocking agent that lowers intraocular pressure by reducing aqueous humor production and may increase outflow of aqueous humor. Dosages of more than 1 gtt of 0.5% levobunolol twice daily have not been shown to be more effective. If intraocular pressure not at satisfactory level on this regimen, concomitant therapy can be instituted. However, do not administer 2 or more topical ophthalmic beta-adrenergic blocking agents simultaneously.
Adult Dose	0.5% solution: 1-2 gtt in affected eye or eyes qd 0.25% solution: 1-2 gtt in affected eye or eyes bid Severe or uncontrolled glaucoma: 0.5% solution bid; closely monitor patient >1 gtt (0.5% levobunolol) bid not shown to be more effective; if intraocular pressure not at satisfactory level on this regimen, concomitant therapy can be instituted; do not administer 2 or more topical ophthalmic beta-adrenergic blocking agents simultaneously
Pediatric Dose	Not established
Contraindications	Documented hypersensitivity; bronchial asthma; severe chronic obstructive pulmonary disease; sinus bradycardia; second- and third-degree AV block; overt cardiac failure; cardiogenic shock
Interactions	May cause bradycardia and asystole when used in combination with systemic beta-blockers (may cause additive effects)
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Beta-blockade may potentiate muscle weakness consistent with certain myasthenic symptoms (eg, diplopia, ptosis, generalized weakness); product may have sulfites, which may cause allergic-type reactions in certain susceptible persons

Drug Name	Betaxolol (Betoptic)
Description	Selectively blocks beta1-adrenergic receptors with little or no effect on beta2-receptors. Reduces intraocular pressure by reducing the production of aqueous humor. Consider concomitant therapy if intraocular pressure not satisfactory following this treatment. This beta-blocker tends to be less potent than the nonselective beta-blockers.
Adult Dose	1-2 gtt in affected eye or eyes bid
Pediatric Dose	Not established
Contraindications	Documented hypersensitivity; bronchial asthma; severe chronic obstructive pulmonary disease; sinus bradycardia; second- and third-degree AV block; overt cardiac failure; cardiogenic shock
Interactions	May have additive systemic effects if patient is already on systemic beta-blockers
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Beta-blockade may potentiate muscle weakness consistent with myasthenic symptoms; product may have sulfites, which may cause hypersensitivity reactions in susceptible persons

Drug Category: Miotics

Direct-acting miotics are parasympathomimetic (cholinergic) drugs, which duplicate the muscarinic effects of acetylcholine. These drugs produce pupillary constriction when applied topically and stimulate the ciliary muscles. These effects in turn result in an increase in aqueous humor outflow. In addition, contraction of the iris sphincter produces miosis causing increased tension on the scleral spur (reducing outflow resistance). This, in turn, opens the trabecular meshwork spaces, facilitating aqueous humor outflow. With the increase in outflow, a decrease in intraocular pressure results.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Further Inpatient Care

• Discuss decisions regarding inpatient care versus outpatient care with the consulting ophthalmologist.

Further Outpatient Care

• Assurance of follow-up care is extremely important if the patient is discharged from the ED.

Transfer

• Transfer may be necessary if ophthalmologic consultation is unavailable at a particular hospital.

Complications

• Decreased visual acuity
• Blindness

Prognosis

• In ischemic RVO, the prognosis is extremely poor.
• With nonischemic RVO, the prognosis is much more variable. In one study, up to a third converted to ischemic RVO, half of these occurring within the first 4 months.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Avoid aspirin because it may cause excessive retinal hemorrhages.
• Assess the patient for any underlying pathology that may lead to retinal occlusions.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• Amirikia A, Scott IU, Murray TG, et al. Outcomes of vitreoretinal surgery for complications of branch retinal vein occlusion. Ophthalmology. Feb 2001;108(2):372-6. [Medline].
• Bhagat N, Goldberg MF, Gascon P, et al. Central retinal vein occlusion: review of management. Eur J Ophthalmol. Jul-Sep 1999;9(3):165-80. [Medline].
• Bijayananda P, Nagpal PN, Namperumalsamy P, Kalsi R. Retinal vascular disorders. Ophthal Clin North Am. Dec 1998;11(4):601-617.
• Chiang CC, Begley S, Henderson SO. Central retinal vein occlusion due to hyperviscosity syndrome. J Emerg Med. Jan 2000;18(1):23-6. [Medline].
• Cormack G, Dhillon B. Sudden loss of vision. Practitioner. Dec 1998;242(1593):851-3. [Medline].
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• Hayreh SS. Retinal vein occlusion. Indian J Ophthalmol. 1994;42:109-32. [Medline].
• Hayreh SS, Zimmerman B, McCarthy MJ, Podhajsky P. Systemic diseases associated with various types of retinal vein occlusion. Am J Ophthalmol. Jan 2001;131(1):61-77. [Medline].
• Hayrey SS. Retinal Vascular Disorders. Ophthal Clin North Am. Dec 1998;11(4):559-592.
• Kearns TP. Differential diagnosis of central retinal vein obstruction. Ophthalmology. May 1983;90(5):475-80. [Medline].
• Keenan JM, Kritzinger EE, Dodson PM. Management of retinal vein occlusion. Br J Hosp Med. Feb 17-Mar 2 1993;49(4):268-73. [Medline].
• Kohner EM, Laatikainen L, Oughton J. The management of central retinal vein occlusion. Ophthalmology. May 1983;90(5):484-7. [Medline].
• Morgan A, Hemphill RR. The difficult diagnosis: Acute visual change. Emerg Med Clin North Am. Nov 1998;16(4):825-43. [Medline].
• Opremcak EM, Bruce RA. Surgical decompression of branch retinal vein occlusion via arteriovenous crossing sheathotomy: a prospective review of 15 cases. Retina. 1999;19(1):1-5. [Medline].
• Ostelah MD, Charles S. Surgical decompression of branch retinal vein occlusions. Arch Ophthalmol. 1998;106:1469-71.
• Porcu P, Cripe LD, Ng EW, et al. Hyperleukocytic leukemias and leukostasis: a review of pathophysiology, clinical presentation and management. Leuk Lymphoma. Sep 2000;39(1-2):1-18. [Medline].
• Shah GK, Sharma S, Fineman MS, et al. Arteriovenous adventitial sheathotomy for the treatment of macular edema associated with branch retinal vein occlusion. Am J Ophthalmol. Jan 2000;129(1):104-6. [Medline].
• Shingleton BJ, O''Donoghue MW. Blurred vision. N Engl J Med. Aug 24 2000;343(8):556-62. [Medline].
• The Central Vein Occlusion Study Group. Natural history and clinical management of central retinal vein occlusion. The Central Vein Occlusion Study Group. Arch Ophthalmol. Apr 1997;115(4):486-91. [Medline].
• The Eye Disease Case-Control Study Group. Risk factors for branch retinal vein occlusion. The Eye Disease Case-control Study Group. Am J Ophthalmol. Sep 15 1993;116(3):286-96. [Medline].
• Weinstein R, Mahmood M. Case records of Massachusetts General Hospital. Weekly clinicopathological exercises. Case 6-2002. A 54-year-old woman with left, then right, central-retinal-vein occlusion. N Engl J Med. Feb 21 2002;346(8):603-10. [Medline].
• Williamson TH. Central retinal vein occlusion: what''s the story?. Br J Ophthalmol. Aug 1997;81(8):698-704. [Medline].
• Zun LS. Acute visual loss. Emerg Med Clin North Am. Feb 1988;6(1):57-72. [Medline].

Article Last Updated: Mar 30, 2006