CRAO

Symptoms:

• abrubt, painless vision loss (pain = OIS)
• amaurosis fugax precedes visual loss in 10% of patients
• men:woman = 2:1; mean age = 60; bilateral involvement = 1-2%

Findings:

• VA 20/800 to LP (NLP = ophthalmic artery obstruction or temporal arteritis)
• +APD
• anterior segment normal (except if OIS, can have NVI)
• ischemic whitening of the retina
• cherry red spot at macula
• ONH pallor with splinter retinal hemorrhages
• 20-25% demonstrate visible emboli

Differential diagnoses:

• mild, nonischemic CRVO
• neuroretinitis
• hypertensive retinoathy

Sequelae:

• after 4-6 weeks, retinal whitening dissipates, leaving optic nerve pallor
• arterial collaterals
• absent foveal reflex
• RPE hyperplasia from stress to the RPE
• NVI/NVG = 18% (make referal for panretinal laser photocoagulation)
• after >100 minutes, complete irreversible loss

Causes:

• Blood conditions: coagulopathies or poor blood flow, antiphospholipid antibody syndrome, protein S deficiency, protein C deficiency, antithrombin III deficiency
• Systemic disease: 60% of patients have HTN, 25% have DM, 50% no cause identified
• Heart disease: 30% have carotid artery disease; Refer patients (especially those <50> 50 y/o
• Optic neuritis
• Local trauma producing damage to the optic nerve
• Radiation exposure
• Behcet disease
• Migraine
• Syphilis
• Optic disc drusen
• Prepapillary arterial loops

Management:

• 350mg ASA, agressive digital ocular massage, topical beta blocker, oral Diamox 2 x 250mg (attempt to lower IOP to decrease resistance to nerve and retinal blood flow), breath into brown paper bag (stimulate rtinal arterials)
• Labs:
• CBC w/ differential and platelets
• blood pressure
• fasting BS
• lipid panel
• cholesterol
• ESR (if yes, requires high-dose corticosteroid treatment)
• CRP
• HLA-B27
• FTA-Abs
• HIV
• electrocardiogram with 2-D echo
• transesophageal electrocardiogram
• carotid doppler
• MRI